Game Design in Virtual Reality
DIPLOMARBEIT
zur Erlangung des akademischen Grades
Diplom-Ingenieur
im Rahmen des Studiums
Media- and Human-Centered Computing
eingereicht von
BSc. Onur Gürcay
Matrikelnummer 00827880
an der Fakultät für Informatik
der Technischen Universität Wien
Betreuung: Ao.Univ.Prof. Mag. Dr. Horst Eidenberger
Wien, 1. Jänner 2021
Onur Gürcay Horst Eidenberger
Technische Universität Wien
A-1040 Wien Karlsplatz 13 Tel. +43-1-58801-0 www.tuwien.at

Game Design in Virtual Reality
DIPLOMA THESIS
submitted in partial fulfillment of the requirements for the degree of
Diplom-Ingenieur
in
Media- and Human-Centered Computing
by
BSc. Onur Gürcay
Registration Number 00827880
to the Faculty of Informatics
at the TU Wien
Advisor: Ao.Univ.Prof. Mag. Dr. Horst Eidenberger
Vienna, 1st January, 2021
Onur Gürcay Horst Eidenberger
Technische Universität Wien
A-1040 Wien Karlsplatz 13 Tel. +43-1-58801-0 www.tuwien.at

Erklärung zur Verfassung der
Arbeit
BSc. Onur Gürcay
Hiermit erkläre ich, dass ich diese Arbeit selbständig verfasst habe, dass ich die verwen-
deten Quellen und Hilfsmittel vollständig angegeben habe und dass ich die Stellen der
Arbeit – einschließlich Tabellen, Karten und Abbildungen –, die anderen Werken oder
dem Internet im Wortlaut oder dem Sinn nach entnommen sind, auf jeden Fall unter
Angabe der Quelle als Entlehnung kenntlich gemacht habe.
Wien, 1. Jänner 2021
Onur Gürcay
v

Acknowledgements
First of all, I would like to thank Prof. Eidenberger for supporting me through my years
at TU Wien and helping me restore my self-confidence.
I would also like to thank Ahmed Othman who also worked on the Vreeclimber project and
prepared the template everyone is currently using for their virtual climbing applications.
He always tried to make time whenever I needed someone’s help during the development
and evaluation stages of the thesis.
I also want to thank my sister, Burcu Gürcay-Morris, who has always been there for me
and ready to help no matter what.
And lastly, I want to thank my test group for making time for me in the current state of
the world.
vii

Kurzfassung
Das letzte Jahrzehnt hat sehr große Verbesserungen in der Virtuelle Realität (VR)-
Technologie gezeigt. Neben Gaming wird VR in vielen unterschiedlichen Bereichen wie
im medizinischen Bereich verwendet. Beispielsweise können Chirurgen lernen, kompli-
zierte Operationen mehrmals in VR durchzuführen, ohne das Leben ihrer Patienten zu
riskieren. Die Möglichkeiten wie in diesem Beispiel erweiterten die Anwendungsbereiche
bedeutend, als der führende Sektor, Gaming, für die Verbraucher attraktiver wurde. Viele
Spieleentwicklungsunternehmen begannen, immersive Erlebnisse zu produzieren, welches
zu der Stärkung ihrer Position auf dem Markt durch die Gewinnung neuer Benutzer
führte. Trotz all dieser Entwicklungen bleibt VR-Gaming jedoch immer noch hinter
dem traditionellen Videospielerlebnis zurück, hauptsächlich aufgrund des Mangels an
hochwertigen Inhalten und der zusätzlichen Kosten, die mit VR-Geräten einhergehen.
Der Hauptgrund für die Knappheit an hochwertigen Inhalten ist, dass das Erstellen von
VR-Spielen immer noch das Ausprobieren neuer Ideen erfordert, in dem das allgemeine
Wissen über Spieldesign verwendet wird, das aus der Entwicklung von Videospielen
stammt. Die Tatsache, dass der Spieler in VR-Spielen präsent ist, sollte die Perspekti-
ve der Spieledesigner beim Aufbau der Erfahrung ändern. Die Spieledesigner müssen
Spieldesign-Elemente wie Ästhetik, Herausforderungen und Wiederspielbarkeit anpassen
und so ändern, dass die VR für die Spieler immer noch überzeugend sein kann. Um
diese inhaltlichen Probleme anzugehen, untersucht diese Diplomarbeit die Anwendbarkeit
verschiedener digitaler Spieldesignelemente auf VR-Spiele durch die Entwicklung eines
VR-Spiels namens Astroclimb. Astroclimb ist ein Science-Fiction- und Weltraumspiel,
bei dem es darum geht, eine Himmelswand im Weltraum hochzuklettern. Der Kletterteil
des Spiels findet dank des Vreeclimber-Projekts der TU Wien auch in der Realität statt,
einem VR-Klettersystem, das eine unendlich rollende Kletterwand ermöglicht.
Während der Entwicklungsphase von Astroclimb waren die Verbesserungen der Qualität
der Benutzererfahrung und des Ermöglichens einer hohen Immersion-Stufe die Hauptziele
von Astroclimb. Die endgültige Version des Spiels wurde von einer kleinen Testgruppe mit
Fragebögen und optional kurzen unstrukturierten Interviews sowie die Beobachtung des
Spielers während des Durchspielens evaluiert. Die Auswertung zeigte, dass die Anwendung
verschiedener Spieldesign-Elemente erfolgreich die Immersion im Spiel steigerte und das
Spiel für die Spieler attraktiver machte.
ix

Abstract
The last decade showed immense improvements in Virtual Reality (VR) technology. VR
is used in many different areas other than gaming such as in the medical area. As an
example, surgeons can learn how to perform certain complicated surgeries over and over
in VR without risking anyone’s life. The possibilities such as this example widened its
application areas significantly as the leading sector, gaming, became more appealing to
consumers. Many game development companies started to produce immersive experiences
which led to strengthening their position on the market by attracting new users. However,
VR gaming still falls behind the traditional video gaming experience mainly due to the
lack of quality content and the additional costs that come with VR devices. The main
reason behind the scarcity of quality content is that creating VR games still involves
trying out new ideas by using the general knowledge of game design inherited from
developing video games. The fact that the player is present inside VR games should
change the perspective of the game designers while building the experience. They need to
adapt game design elements such as aesthetics, challenge, and replayability and change
them in such a way so the VR can be still compelling to players. To address these
content-related issues, this thesis investigates the applicability of different digital game
design elements onto VR games by developing a VR game called Astroclimb. Astroclimb
is a science fiction and space-themed game that revolves around climbing a celestial wall
in outer space. The climbing part of the game also takes place in reality thanks to the
Vreeclimber project of TU Wien, which is a virtual reality climbing system that enables
an infinitely rolling climbing wall.
During the development stage of Astroclimb, improving the quality of user experience
and the level of immersion were the two main goals for Astroclimb. The final version of
the game was evaluated by a small test group with questionnaires and optional short
unstructured interviews as well as observing the player during the playthroughs. The
evaluation showed that the application of different game design elements successfully
increased the immersion level in the game and made the game more compelling to players.
xi

Contents
Kurzfassung ix
Abstract xi
Contents xiii
1 Introduction 1
1.1 Problem Statement and Motivation . . . . . . . . . . . . . . . . . . . . . 1
1.2 Aim of the Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2
1.3 Methodological Approach . . . . . . . . . . . . . . . . . . . . . . . . . 3
1.4 Thesis Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
2 State-of-the-Art 7
2.1 Virtual Reality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
2.1.1 Evolution of Virtual Reality over the Last Decade . . . . . . . 7
2.1.2 Application Areas . . . . . . . . . . . . . . . . . . . . . . . . . 9
2.1.3 Interaction Techniques . . . . . . . . . . . . . . . . . . . . . . . 12
2.1.4 VR Game Development . . . . . . . . . . . . . . . . . . . . . . 15
2.1.5 Game Releases . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
2.2 Game Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.1 Definition of Game . . . . . . . . . . . . . . . . . . . . . . . . . 19
2.2.2 Digital Game Design Elements . . . . . . . . . . . . . . . . . . . 21
2.2.3 Game Mechanics . . . . . . . . . . . . . . . . . . . . . . . . . . 24
2.2.4 Playtesting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
2.2.5 Reflection on Virtual Reality . . . . . . . . . . . . . . . . . . . 27
2.2.6 Immersion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
2.2.7 Motion Sickness . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
2.3 Climbing in Virtual Reality . . . . . . . . . . . . . . . . . . . . . . . . 32
2.3.1 Traditional Indoor Climbing . . . . . . . . . . . . . . . . . . . . 32
2.3.2 Virtual Climbing . . . . . . . . . . . . . . . . . . . . . . . . . . 33
2.3.3 Virtual Climbing Technologies . . . . . . . . . . . . . . . . . . 35
2.4 Related Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37
3 Conception of Astroclimb 41
xiii
3.1 Requirements for Designing the Game . . . . . . . . . . . . . . . . . . . 41
3.2 Design Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42
3.3 Included Game Design Elements . . . . . . . . . . . . . . . . . . . . . 44
3.4 Possibilities for Improvement . . . . . . . . . . . . . . . . . . . . . . . 46
4 Implementation of Astroclimb 49
4.1 Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2 Created Scenes in the Game . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.1 The Moon Scene . . . . . . . . . . . . . . . . . . . . . . . . . . 49
4.2.2 The Owl Scene . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51
4.2.3 The Asteroid Belt Scene . . . . . . . . . . . . . . . . . . . . . . 52
4.3 Gameplay and Atmosphere in the Game . . . . . . . . . . . . . . . . . 55
4.3.1 Game Chapters and Events . . . . . . . . . . . . . . . . . . . . 55
4.3.2 Score, Timer, and Height Indicators . . . . . . . . . . . . . . . 56
4.3.3 Modeling and Use of Game-ready Assets . . . . . . . . . . . . . 57
4.3.4 Music and Sound Effects . . . . . . . . . . . . . . . . . . . . . . 59
4.4 Technical Aspects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.4.1 Calibration Process . . . . . . . . . . . . . . . . . . . . . . . . . 61
4.4.2 Scripts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 62
5 Evaluation 65
5.1 Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65
5.2 Covid-19 measures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.3 Testing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
5.4 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5.4.1 Immersion, Aesthetics, and Story . . . . . . . . . . . . . . . . . 70
5.4.2 Fun, Tiredness, and Motion Sickness . . . . . . . . . . . . . . . 72
5.4.3 Problem Solving, Critical Thinking, and Replayability . . . . . 74
5.4.4 Element of Surprise, Curiosity, and Progression . . . . . . . . . 75
5.4.5 Overall Results of Applying Game Design Element . . . . . . . 77
5.5 Discussion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 79
6 Conclusion and Future Work 81
A Step-by-step Test Procedure 83
List of Figures 85
Bibliography 87
CHAPTER 1
Introduction
1.1 Problem Statement and Motivation
This diploma thesis focuses on applying traditional game design elements used for video
games to virtual reality games without making any concessions to the most important
aspect of virtual reality “immersion” [97] and improving it if possible. Virtual reality is
still a fairly new technology. Game development in this area has not gained the popularity
of PC, console, or mobile gaming yet. There are several reasons for this unpopularity
which can be divided into hardware and software-related problems. One of the main
hardware-related issues is the price of the device and the additional costs it brings with
itself. Apart from the price drawbacks, virtual reality devices are still clunky to use
and discourage users to even try them out. Technology still needs time to improve the
hardware and increase the usability of virtual reality devices.
Software-related issues are mainly content-based because people do not want to pay for a
relatively expensive device if the amount of the game content they will receive with it is
lacking or not as high quality as on PC or console platforms. These reasons and many
more have been causing a deficiency of consumer attraction to virtual reality compared
to PC, console and mobile gaming which did not help with shaping the necessary game
design properties for virtual reality. To shade a light on the content-related problems and
define possible game design principles for virtual reality, the diploma thesis investigates
the following research questions:
• Are common and generally accepted game design practices and methods directly
applicable to the virtual reality platform? In what way do core concepts of digital
game design such as immersion, usability, and game feel mean differently when
applied to the virtual reality experience?
• At what level can problem solving, critical thinking, elements of surprise and
1
1. Introduction
suspense, physical training and activity, engagement, and competition be applied
while designing a game for virtual reality platforms to increase the quality of user
experience without any negative side-effects for virtual reality?
The thesis explores the mentioned points in order to make virtual reality game design more
appealing and enjoyable to users without causing any disadvantages such as decreasing
the immersion or bolstering cybersickness that comes with it.
1.2 Aim of the Work
The thesis aims to design a game for the ongoing virtual reality project called Vreeclimber
[35]. Vreeclimber’s infrastructure consists of a vertically rolling climbing system that
enables the climber to experience the sensations of climbing in a perfectly safe environment.
Since the mechanical and logical aspects of the project are finalized, it opened up
opportunities to create content for the project. The content of the game is based on a
playground in a deep space where the player has the mission to climb a celestial wall.
The pure reason behind this choice is providing players with an environment that would
give them a unique experience.
Vreeclimber’s template project comes with algorithms that enable climbing in virtual
reality via a calibration process. The calibration process initially detects the trackers on
the wall to align the physical wall and the climbing holds with their virtual representation
in the virtual environment. In addition to the initial calibration process, the climbing
holds remain aligned during the rotation of the wall. Avatar hands and shoes used in the
virtual environment are the second part of the calibration process, enabling players to
track their hands and feet accordingly.
The implementation of the game aims to include various game design elements which
should make sense with the planned gameplay for the game. The first gameplay ideas
that were considered are listed below:
Difficulty levels The difficulty level of the climbing can be adjusted by rendering out
a certain number of available climbing holds which leaves the climber with a smaller pool
of climbing holds to choose from during the climb. The smaller the number of climbing
holds the more challenging the climb becomes.
Sandbox mode This mode represents no winning or losing as the term “sandbox”
states. However, a scoring system can be defined for using specific types of grips during
the climb. Grasping those grips would yield a higher score in the end. Competition
elements can be added by creating a global scoreboard or the climbers can simply try to
beat their personal bests.
Transitions between scenes The look of the virtual environment can be changed
based on the progression players made throughout the game.
2
1.3. Methodological Approach
The implementation is mainly based upon these gameplay ideas with some modifications
and adaptations to the game design elements. During the game design and implementation
processes, the differences between designing a video game and a virtual reality game
should be considered in order to take advantage of the virtual reality aspect. The applied
game design elements should furthermore be in harmony with each other to increase the
quality of user experience without lowering the immersion levels. The prototypes should
be created following these points.
After each game prototype, the functionality and the effects of the added game design
elements should be tested. Based on the given feedback, the appropriate parts of the game
should be adjusted to meet the requirements and improve the overall user experience.
After the creation of a satisfactory prototype, a test group corresponding to the scope of
a thesis should be used to evaluate the success rate of the used game design elements,
their impact on the quality of user experience and immersion.
1.3 Methodological Approach
The methodological approach compromises of the following steps:
1. Literature Review: Firstly, research on the definition of “game design” and its
elements is done while investigating how they changed over the years with the
advancements in technology and if virtual reality played a role in these alterations.
This part of the research was important to understand the influence of virtual
reality on game design. Since there was not a single set of game design elements
that are accepted globally, a long list of different game design elements and their
sub-elements was created. The next step was narrowing the list down by eliminating
the ones that are not compatible to virtual reality. The elimination happened per
definition and choice since it is impossible to include every single game design
element that is mentioned in the literature. The result of this part of the research
was a new categorization of game design elements that are commonly accepted
and game design elements specific to virtual reality games. Another part of the
research was determining the advantages and disadvantages virtual reality brings
to the table while designing games. The gathered information helped with filtering
the game design elements further. In addition to these findings, further research
on the effects of using chosen game design elements on the players helped improve
the user experience. Furthermore, it improved forming directives to come up with
better game-play ideas.
2. Implementation: The implementation of the game prototype was performed by
using Unity game engine with the help of Steam virtual reality software for virtual
reality capabilities. Previously mentioned game-play ideas were the starting point
for the implementation part. Since the center point of the game is climbing a
physical climbing wall with supporting virtual representations, some of the used
assets were pre-defined such as the virtual climbing wall and avatar hands. They
3
1. Introduction
were a must-have to achieve simple climbing in a virtual reality environment. The
composition of the objects in the virtual environment was created by modeling
and using game-ready assets. Adding game design elements to the game started
with creating the environment and continued with implementing the gameplay.
Some game components were modified or removed throughout the implementation
process to meet the requirements and provide players with a better experience.
Furthermore, the calibration process received some adjustments to meet the game-
play requirements. During the whole implementation process the most important
aspect of virtual reality, immersion, is kept in mind so the ideas or added game
components do not break it.
3. Playtesting: During the whole implementation process, every added feature was
tested and feedback was given based on the experience from the test sessions. The
testing sessions and received feedback helped with improving the weak points of the
game. Moreover, playtesting also proved and disproved some ideas that sounded
reasonable during the brainstorming process.
4. Evaluation: The evaluation process consisted of different methods to gather data
from the participants. The initial method was using a questionnaire to gather
information about participants’ gaming and climbing habits and experiences before
the climb. The participants were further encouraged to think aloud during their
game sessions. A second questionnaire was handed over to the participants after
their experience with Astroclimb to gain insight into their experience regarding the
immersion level they perceived, the impact of using different game design elements,
and quality of user experience. Moreover, a short unstructured interview was
conducted afterwards to receive further feedback to improve the game and user
experience.
1.4 Thesis Structure
The second chapter of the thesis presents the current state-of-the-art. The section starts
with giving some information about the evolution of virtual reality over the last decade,
virtual reality application areas, and its possible interaction techniques. It then explains
the stages developing a game goes through. The subsection also includes some virtual
reality game examples on the market and their comparison with each other. The game
design subsection covers the definition of “game” which gives insight into game design
elements. It also explains what game mechanics mean for a game and how playtesting is
a crucial part of the game design life-cycle. All these aspects are then reflected in virtual
reality. It further clarifies the advantages and disadvantages virtual reality brings. The
importance of immersion in virtual reality and motion sickness covers the next subsections.
Moreover, climbing in virtual reality and the tools that enable this experience forms the
last sections together with the related work done in the research area.
4
1.4. Thesis Structure
The third chapter covers the conception of the game. The first subsection explains the
research questions and requirements that are necessary to create a specific concept of the
game. The design approach covers the ideas behind designing the game and why this
approach is chosen based on given tools to work with. The section also informs about
the chosen game design elements and their effects in the game. Lastly, the possibilities
to improve the game are discussed.
The fourth chapter includes all relevant aspects of technically designing Astroclimb while
the fifth chapter reflects results from the evaluation. The last chapter gives a short
summary of the whole work done for the thesis and possible future work that can be
achieved with the project Vreeclimber.
5

CHAPTER 2
State-of-the-Art
2.1 Virtual Reality
2.1.1 Evolution of Virtual Reality over the Last Decade
Virtual reality has been around for decades, however, it has only recently started to gain
momentum due to advancements in science and technology. These improvements brought
the current state of virtual reality to a point that made it look far different than how
it started with Sutherland’s “The Ultimate Display" [26]. How we view and use virtual
reality changed over the decades with the impacts of multiple breakthroughs in research
and innovation.
One of these breakthroughs happened with Google introducing Street View in 2007 [53].
Street View is a virtual representation of our surroundings all over the world that is
supported by Google Maps [52]. It consists of millions of panoramic images that enable
people to virtually explore the world. Google, then released a virtual reality version of
Google Earth [51] for Valve’s Steam computer gaming platform and integrated Street
View into Google Earth VR. This update lets the user explore Street View imagery from
85 countries right within Earth VR by using VR controllers [79]. Figure 2.1 shows a user
using an HTC VIVE headset with its controllers to navigate through the world.
Another crucial breakthrough for VR was the design of the first Oculus Rift VR headset
prototype in 2010 [83]. Palmer Luckey, the inventor of the Oculus Rift VR headset,
kickstarted his design in 2012 for enthusiasts to back his project. John Carmack’s [109]
short demonstration of an early version of the prototype at the E3 event [33] helped
Luckey receive more than enough endorsements to reach his goal. Figure 2.2 shows
how the very first prototype was assembled for its display at the expo. The modest
campaign goal of $250,000 broke 2 million dollars in a short time with the generous help
of known gaming industry names such as John Carmack, and Gabe Newell of Valve
7
2. State-of-the-Art
Figure 2.1: With the help of the controller the user is able to select a location on the
small globe and fly towards it. [56]
[77]. A week before Facebook bought the Oculus VR company for $2 billion in 2014 [31],
Luckey released a new version of Oculus Rift called Developer Kit 2 (or DK2). This new
version fixed and improved upon some of the original headset’s flaws such as switching
the technology powering their display from LCD to OLED, decreasing the latency of
the headset from 60 milliseconds to 30 milliseconds, and inserting entirely black frames
in between other frames to see smoothly moving images [87]. The improvements also
helped with reducing the occurrences of motion blur which is one of the main reasons for
motion sickness [102]. The acquisition of Oculus VR by Facebook did not change the
main goal of making games but expanded the use of it in other areas such as education
and healthcare with social networking built-in.
Facebook buying the Oculus VR company was a defining moment in VR’s history because
VR gained momentum after this. Sony announced the development of a VR headset for
the PlayStation 4 (PS4) under the name Project Morpheus [39] which then evolved and
became a part of the equipment for PlayStation5 (PS5) VR games. Google joined the
race with the release of the Google Cardboard [55]. Google Cardboard(Figure 2.3) is
a low-cost and do-it-yourself (DIY) stereoscopic viewer for smartphones. It works by
placing a smartphone at the optimal distance away from the lenses that create a 3D effect
when held up to the eyes. However, it requires compatible apps to work with. Samsung
Gear VR [139] announcement in 2014 was another advancement for VR. Samsung Gear
VR, a headset, uses Samsung Galaxy smartphones as a viewer with similar built-in
functionalities as Google Cardboard has. It then became a part of Sony’s PlayStation
VR (PSVR) in 2016.
In 2015, the use of VR expanded and became widely available to the general public:
• The Wall Street Journal launched a VR roller coaster that followed the ups and
downs of the Nasdaq Stock Market. [137]
• The BBC created a 360-degree video where users view a Syrian migrant camp.
[106]
• The Washington Post released a VR experience of the Oval Office at the White
8
2.1. Virtual Reality
Figure 2.2: An interviewer tries out
one of the first prototypes of Oculus
VR at E3. [42]
Figure 2.3: A variety of Google
Cardboards. [54]
House Correspondents’ Association Dinner. [1]
• RYOT, a media company, exhibited Confinement, a short VR film about solitary
confinement in US prisons. [138]
More releases followed in 2016 that focused on the free movement of users while wearing
a headset. HTC VIVE SteamVR headset [134] was one of them. This was the first
commercial release of a headset with sensor-based tracking which allowed users to move
freely in a space. Two years after that Facebook released its untethered Oculus Go
headset [117].
Further developments such as many companies developing their own VR headsets including
Google, Apple, Amazon, Microsoft, Sony, and Valve accelerated the advancement for
VR headsets. Valve Index [71] was released in 2019 and is currently if not the best one
of the best VR headsets on the market [47]. It provides an optimized pixel layout with
dual 1440x1600 RGB LCDs greatly reducing the “screen door” effect [113] VR headsets
had to deal with especially in the early stages of developments. Moreover, the headset
runs at 120Hz with an experimental option of 144Hz improving the realism and optical
comfort of the users which also reduces the possible occurrence of motion sickness [78].
Besides these features, increment in field of view (FOV) to 130 degrees (perceived as 120)
makes the users feel more present in the experience [75].
Virtual reality has significantly advanced and is now being used in a variety of ways,
from providing immersive gaming experiences, to helping treat psychological disorders,
to teaching new skills and more. Now that we are aware of important technological
advancements in VR, the next subsection dives into a collection of application areas of
VR and informs how different areas take advantage of these improvements.
2.1.2 Application Areas
VR has attracted a lot of people in the last decade which led companies to adopt and
improve it [122]. With the help of the tools VR brings to the table users are able to
9
2. State-of-the-Art
manipulate the simulated world in a natural way. Since the simulated world can be
designed in an infinite number of possible ways, VR opens many doors for people to get
creative and achieve their goals in different areas. Figure 2.4 shows which application
areas VR favors in terms of market share. The remaining of this section focuses on how
VR got embraced by different application areas and what kind of great benefits VR
provided them.
Figure 2.4: Global VR headset market share, by application, 2020 (%) [130]
1. Gaming: Gaming with VR gives players a truly immersive, first and third-person
perspective of game action. VR lets players experience and influences the game
environment through a variety of VR gaming devices and accessories, including
VR headsets, sensor-equipped gloves, controllers, trackers, and more. The next
subsection goes into details about these interaction devices and methods. VR
games can be played on standalone systems, specialized game consoles, or using
PCs and laptops that can power VR headsets. PC and console-tethered headsets
usually have better performance and provide a more immersive experience, while
mobile headsets are relatively inexpensive and easier to set up and use. Although
the bodily movements in real life are not translated to that in VR for standalone
headsets except the head rotations to view the space in 360-degree environments,
companies such as Facebook, Google, and HTC are developing cheaper mobile VR
devices to attract more users to adopt VR headsets [95]. Gamers have a higher
average outlay for upgrading their gaming PCs and consoles compared to people
who do not indulge in gaming. This has encouraged companies to capitalize on
VR games within the reasonable price range for gamers [136]. These VR games
have the same scope as traditional video games including single, cooperative, and
online multiplayer games. Some of these games place players in physical combat
environments, while others provide more relaxing letting players traverse worlds
and various spaces. Other VR games take players on adventures by challenging
them to solve problems and explore unknown places. Section 2.1.5 gives more
insight into different types of games and provide examples.
2. Entertainment: Although gaming is also a part of the entertainment application
area, it deserves its own section because of the influence it alone has on the
10
2.1. Virtual Reality
market. Besides gaming, VR has other applications for entertainment such as
providing virtual museums [136] and galleries [8]. These setups make visitors the
center point of interactive exhibitions so that they can take a tour in these virtual
environments. Some of these environments also provide scene manipulation options
such as arranging the position of artworks and changing the lighting and color of the
walls as needed. Virtual theme parks [32] are another great example of using VR
for entertainment purposes. VR gives people the opportunity to visit theme parks
and join rides such as Tron at Shanghai Disneyland [131] and Jurassic World The
Ride at Universal Studios Hollywood [63] while they are sitting on their couches.
Another entertainment source VR provides is letting people join music concerts
and be on the stage to experience live music. Virtual concerts [86] come with many
benefits for the user from seeing admired artists without having to leave home, to
not worrying about getting a good seat, to being able to adjust the volume, and
more. Although these remote entertainment opportunities come with benefits there
is still room to improve. Improving the visual quality and making the audio more
spatial would be essential improvements to increase immersion and therefore the
user experience.
3. Healthcare: Due to VR’s interactive nature and simulative aspect, medical train-
ing and mental health rehabilitations stood forward for this application area.
Medical and dental students have begun using VR to practice surgeries and proce-
dures [160], allowing for a learning environment without having consequences of
making mistakes. Therefore, the risk of inflicting harm on patients while practicing
is eliminated. OssoVR [181] is one of the well-known platforms that provide surgical
training and assessment. With the help of VR, students can develop skills in various
simulations which can later be applied in real-world scenarios. Besides the benefit of
training high-skill personnel, VR creates a great opportunity to optimize costs [27].
Patient treatment has also become one of the core application areas in healthcare.
Pain management is an example where VR captures the mind’s attention and
blocks pain signals from reaching the brain [14]. Stress and depression treatments
are further examples in this area. Moreover, VR also proved to be a promising and
motivating platform to safely practice and rehearse social skills for children with
Autism Spectrum Disorders (ASD) [29].
4. Education: VR provides various ways to enable education between students and
teachers. VR education gives the opportunity to make learning experiences social
by allowing students to communicate with each other. Using avatars and mapped
facial expressions [38], students can come together to discuss, synthesize, and
learn from one another. All of these can be achieved by distance learning [128].
Students can be put together in the same room with digital representations of
themselves while teachers guide them through their knowledge and experiences.
Another possibility VR provides is letting students experience places across the
world without leaving the classroom. The technical part of this possibility includes
using the 360 VR technology. 360 VR contents are interactive and immersive
11
2. State-of-the-Art
experiences that completely surrounds a user as if they are standing in the middle
of a scene. The user can look in any direction, allowing them to see and interact
with the content as they would in real life [2]. Real-world locations are captured
with special equipment using 360 VR and then the footage is used to create these
captured locations into VR environments. Although VR is currently not as popular
as other application areas such as gaming and healthcare, the growth of VR within
education in previous years [72] shows potential for VR to become one of the most
used learning tools in near future. ClassVR [180] is a step in the right direction to
expand the horizons of VR in education. It presents an open platform, supporting
virtual, augmented, and mixed reality curriculum content, as well as allowing
students and teachers to create, upload, and share their own content, creating a
collaborative community of global educational resources.
5. Retail: VR usage favors both retailers and customers in this application area.
The focus point of using VR from the retailer’s perspective is training employees.
In 2017, Walmart provided VR headsets to Walmart Training Academies to train
associates in handling daily tasks and situations such as managing the frozen
section and various events like Black Friday [69]. Another mention-worthy VR
advancement in retail is eBay’s VR store which functions via gaze-based interaction.
eBay launched the world’s first virtual reality department store in partnership
with Australian retailer Myer in 2006 [104]. In this virtual shop, customers can
select their areas of interest at the beginning of the experience and the store builds
itself around these needs. Customers are additionally able to browse through the
products, gain detailed information about them and purchase them.
The application areas of VR are, of course, not limited to the ones listed above and the
ones seen in Figure 2.4, however, this section covers only some of the most important
ones. VR needs various interaction techniques and devices to serve its purpose in order
to enable human and computer interaction in these application areas. The next section
dives into these different types of interaction techniques and devices.
2.1.3 Interaction Techniques
VR users can enhance their experience in virtual environments by increasing the level
of immersion they perceive. One of the most important ways of achieving this is using
various interaction techniques that would make the environment feel natural. This
section explores some fundamental interaction concepts such as selection, manipulation,
locomotion, and social interaction with the specialized devices that enable these concepts.
1. Selection: Selection involves telling the system which object or UI element the
user wishes to interact with. Once an object or UI element is selected it becomes
the center of focus, so further interaction inputs can be processed for it. Selection
can be performed using controller input, gestures, or gaze. Vanacken et al. [173]
came up with design guidelines for selection techniques that include the selections in
12
2.1. Virtual Reality
virtual environments to be fast, accurate, easy to understand, produce low levels of
fatigue, and more. The devices that were developed in the last decade followed this
suit to improve the quality of user experience. Controller input is one of the most
widely used techniques for this purpose. In this technique, a virtual laser-pointer
(ray-cast) is fired from the controller to select objects. The user can change the
controller orientation to aim the laser beam at desired objects. Although as of
right now there are different variations of VR controllers on the market (Figure
2.5) that are used in many application areas, this type of selection technique is
still used. Using gestures is another way to select objects in virtual environments.
Figure 2.5: From left to right: HTC VIVE [178], Sony PlayStation Move [126], Oculus
Touch [118], Valve Index [70] controllers.
Precise tracking of hands and fingers is a requirement in order to achieve selection
via gestures. Leap Motion controller [166] was one of the first devices that achieved
finger tracking in short distances. It is based on an optical hand tracking module
that captures the movements of hands without any further requirements such as
wearing a piece of clothing. Manus Prime II [101] motion capture gloves are another
example of precise finger tracking that involves wearing a sensor-equipped piece
of clothing. As the technology for hand tracking evolved, this type of tracking
started to get integrated into VR headsets. Newer devices such as Oculus Quest
[119] support native hand tracking. Common interaction techniques such as using
a laser beam cast from a hand coupled with a pinch gesture can be used to confirm
the selection of an object. Nearby objects can, of course, be grabbed naturally by
the visual representations of tracked hands without any further combination of
selection techniques.
Gaze-based selection involves the head-pose or actual eye-gaze which can be tracked
by the gyroscopes inside VR headsets [92]. The selection interface usually consists
of a reticle or a cursor displayed in the virtual world as seen in Figure 2.6. The
process of selecting through gazing starts with the user looking directly at the
object. Then the selection can be confirmed via either an external controller input
or staring at the target for a certain amount of time.
2. Manipulation: Once an object is selected, the user may also want to manipulate
the object. Resizing, moving, reorienting, scaling, and rotating it are some of the
available manipulative actions the user can apply to objects. The limits of these
13
2. State-of-the-Art
Figure 2.6: An example for a gaze-based selection cursor in Unity. [94]
interactions depend on the available input controller’s capability. These can change
from simply rotating the controller itself to complicated actions such as performing
hand gestures. One of the widely used manipulation techniques is simply rotating
an object just to inspect it while holding it in possession. If the held object has
a complex structure and just rotating the object is not sufficient to inspect it in
detail, then it might require simultaneous inputs from different devices such as
multiple controllers or tracked objects such as avatar hands [91]. In this case,
while the object can be held and rotated with one controller, a part of the object
can be further manipulated by the inputs of the second controller. Moreover, the
user could even hold a real object in hand that is tracked by external cameras
and manipulate it which would yield haptic feedback to the user. Another way
of tracking objects is using special trackers such as VIVE Trackers [179] that can
be attached to real objects. The user then can manipulate these objects e.g. with
their tracked hands or feet in the virtual world.
3. Locomotion: While selection and manipulation focus on the interaction with
objects in the virtual environment, locomotion enables user movement within the
virtual world. These movement types mainly consist of repositioning and reorienting
the user. There is a decent number of locomotion interaction techniques that are
used widely in different application areas [94]. One of them is called “On-Rails”
where the user has no control over their movement in VR [6]. VR roller coaster
describes this experience best because the user rides along while only being able to
look around. The most important challenge on-rails locomotion interaction poses
is reducing or eliminating the feeling of disorientation [94]. Section 2.2.7 goes into
details regarding this type of VR sickness.
Gaze-directed steering[84] is an extension to on-rails movement type where the user
moves in the direction they look. The velocity of the movement can be constant or
vary throughout the movement segment by different input triggers. The Jumpcube
[34] project includes various gaming applications where the movement is based
on gaze-directed steering. “Mission TU Mars”, a solar system flight application
developed in Unity, includes this type of locomotion interaction technique where
the user traverses the space and changes directions based on the direction they
14
2.1. Virtual Reality
look.
Teleport is another locomotion technique to traverse large spaces in a short time.
Users can use controller-based or gaze-based raycast to select an area of the virtual
environment they want to move to and trigger the teleportation by a controller
input. More advanced teleportation methods can include rotation specifications
where the user can specify the direction they want to face when they teleport.
Real movement also counts as one of the locomotion interaction techniques where the
user can simply walk around the virtual world. However, walking around without
seeing the real environment increases the risk of collision with real-world objects.
Some manufacturers such as Oculus provide some sort of proximity alert system to
protect users from possible accidents [116]. Other solutions to limited traversing
area problems include omnidirectional treadmill simulators such as Virtuix Omni
Platform [68] and The Virtualizer [76] that use a special platform to simulate
endless locomotion in every direction. However, these devices are currently only
available for commercial providers and not for end-users.
4. Social Interaction: Social VR gives users the opportunity to meet other people
and talk to them in virtual reality. The spatial presence aspect of social VR can give
people a sense of belonging and fulfillment in a simulated world. The current state of
the world due to the Covid-19 pandemic increased these needs immensely [149][88].
Social interaction includes some or all other interaction techniques presented in
this section, however, it uses these interaction techniques to enhance the ability of
people to interact with each other as they are present in a simulated world.
This section provided us with valuable information on how to use different interaction
techniques in VR. Before using this information and investigating how VR games took
advantage of these interaction techniques, we will look into game development in the
next subsection to build a base for the last section of Section 2.1.
Figure 2.7: The potential of VR applications by category. [60]
2.1.4 VR Game Development
The advancement in VR made VR game development become a popular investment
[73]. VR headset sales hit their peak over the last few years and the demand for
especially standalone VR devices is expected to grow dramatically at least until 2022
[122]. According to research by the International Data Corporation (IDC), VR and
15
2. State-of-the-Art
AR market will reach 15.5 billion euros by 2022, and as seen in Figure 2.7 the video
game sector will keep leading the highest market value of VR applications [60]. Besides
showcasing the popularity and importance of VR game development in the market, this
brings us to explaining the crucial points of developing these high-value VR applications.
Instead of explaining every game development stage, we will focus on the points that are
decisive to the virtual reality aspect of game development.
Game development starts with a game idea and planning. During the planning stage,
the target audience should be defined and the characteristics of the game should be
constructed. These characteristics should help with answering the question “Why should
my game use VR?” [174]. Once these initial steps are completed, the target VR devices
for the game should be chosen. The reasons behind this decision are tightly related to
the genre and the playstyle of the game. Light mobile VR is a good choice if the game
does not require motion sensors and head movements. These types of games fall under
the category of mobile games. Google Cardboard is an example of this kind of device
which also carries the title of being the least expensive VR headset on the market by
costing around €10 [54]. Premium Mobile VR devices such as Samsung Gear VR [139]
and Google Daydream [50] are further choices for mobile games with an additional set
of sensors for head movements. PC and console VR are the high-end platform options
for games. As explained in Section 2.1.2 and 2.1.3, these high-end VR headsets provide
high-level immersion and various interaction techniques a VR game would need. The
tools this equipment offer to developers possess a high range of possibilities to bring their
game ideas alive and as imagined.
The next step would be deciding on the type of graphics for the VR game. A VR game
development cost depends significantly on the game’s graphic design. Below is a list of
types one can use for game graphics [23]:
• 2D graphics
• 3D graphics
• Photorealistic graphics
• 360 panoramic views
As 2D graphics usually adopt the cartoonish style, they can still look professional,
detailed, and complex which brings this option on par with 3D graphics. On the one
hand, photorealistic graphics require significant investment and budget especially if the
game imitates nature but on the other hand, they can provide the most realistic aesthetics
possible for a game. The other option, 360 panoramic views, gives the opportunity to
add a panoramic view to the background of the games. Adding interactive elements to
the video can, however, presents challenges and become computationally expensive [23].
The development platform would be another important decision to make during the game
development cycle. Although there is a definite diversity of VR development tools on the
16
2.1. Virtual Reality
market for the end-users, Unity [161] and Unreal Engine [44] take the lead because of
being free of charge and their wide support in tools, graphics type, operating systems, and
ease of use. Once all these decisions are made and other fundamental game development
stages [124] are processed accordingly, the next step would be publishing. For this matter,
there is a variety of markets for VR games that include Oculus Store [115], Google
Play Store [125], Apple App Store [7], Steam [172], and VIVEport [177]. Although the
popularity of these markets may vary, they form the default way to distribute content on
a range of devices.
Creating a VR game is at base not much different than developing a traditional video
game. The limitations, advantages, and additional requirements it brings create that
difference during the development process. This section clarified how developing a VR
game has its deciding points that would affect the outcome significantly. Now we will
look into some of the most successful games in VR history from different genres that are
played by millions.
2.1.5 Game Releases
This section is an overview of some of the most successful VR games on the market. The
main goal of this subsection is to investigate different types of games while looking into
the reasons behind their success.
Figure 2.8: Traversing options in Half-Life: Alyx. [11]
1. Half-Life: Alyx: Half-Life: Alyx [151], released in 2020, is a first-person shooter
(FPS) game that tells the story of an impossible fight against a vicious alien race
known as the Combine [151]. The main gameplay consists of looting and shooting
enemies that are encountered throughout the game. Half-Life: Alyx is considered
one of the most successful VR games in VR history [89] as it became Steam’s [172]
best and most rated VR game less than a year after launch. Valve’s game designers
Robin Walker and Greg Coomer stated the points that made the game a success
17
2. State-of-the-Art
story in an interview with Norman Chan [140]. Besides its beautiful graphics,
the game provides simultaneous 2-hand input to make the player more immersed
with the use of specially designed avatar hands. Players are able to interact with
many objects in the area with different input combinations applied to controllers.
Moreover, the duo informed that the density of interaction played a crucial role in
constructing the environment. Because of the high number of interactable objects
in the environment testers tend to traverse the space slower than a player would
do in a normal video game. This changed the way they designed the levels in
the game and made the interaction with objects rewarding. Another important
point mentioned was the way players traverse in the game. They did not want to
ignore the ability to traverse space and made it for players so that they can move
slowly with the help of controller inputs. However, they still kept the possibility of
blinking from one point to another to appeal to different types of gameplay. Figure
2.8 displays the types of movement in the game.
2. Beat Saber: Beat Saber [43], released in 2019, is a VR rhythm game that evolves
around slicing blocks representing musical beats with a pair of contrasting-colored
sabers. In an interview [16] one of the game designers, Vladimir Hrincar, mentioned
that the surrealistic neon environment created for players is inspired by the movie
TRON: Legacy [105]. Beat Saber provides the player two lightsabers which can
be controlled by rotating the controllers. As the cubes of different colors that are
supposed to be sliced fly towards the player, the player tries to slice the cube with
the lightsaber of matching color (Figure 2.9). All levels created in the game have
different difficulty levels which encourage players to retry and beat their scores.
Although the gameplay is pretty simple the game became popular on the market
and made the game one of the most successful VR games.
3. The Room VR: Dark Matter: The Room VR: Dark Matter [46] is the first
VR game of the well-known puzzle video game series The Room [45]. It expands
various types of puzzles around small environments at first before luring players
into bigger places such as an ornate church that holds its own series of secrets.
Each scene has a collection of hot spots for players to stand in, look around, grab
objects to add to their inventory, and try to figure out what is going on. The clues
players find throughout the game teach how to think about these puzzles for future
reference as much as how to solve the particular puzzle in front of them [82]. The
occurring events and the dark atmosphere in the game add the horror genre to the
game. Interaction with in-game objects is performed by a pair of avatar hands that
are directed by controller inputs (Figure 2.10). Traversing the space only consists
of the teleport mechanism similar to in Half-Life: Alyx.
4. Microsoft Flight Simulator: Microsoft Flight Simulator [108] is a flight sim
that offers its player base a first-person viewpoint to fly over the whole world while
in a cockpit of a plane. Players can examine all the buttons and switches a real
plane cockpit would offer up close. The simulation concept provides a high level of
18
2.2. Game Design
Figure 2.9: The player has to slice
cubes with the correct ligtsaber of
color. [62]
Figure 2.10: Players use their avatar
hands to interact with various ob-
jects. [80]
immersion as players take off and land at airports around the world, fly through the
clouds and admire the landscapes below. If players choose to just enjoy the flight,
the game’s autopilot system takes care of the challenging part of controlling a plane.
However, the option to feel like a real pilot is still there by taking over control
of everything in the cockpit [100]. The interaction part of the game consists of
controller inputs without any in-game body part representations. Microsoft Flight
Simulator’s sandbox style of gameplay lets players enjoy the sight and proves that
VR games can exist without complicated mechanics and still be successful as a
game [164].
So far, the thesis explained the virtual reality side of the main topic with memorable
mentions about gaming and game design aspects. The next section goes more into details
about the game design topic and provides broad information about its building blocks.
2.2 Game Design
2.2.1 Definition of Game
Before giving detailed information about game design, it is important to understand
what really “game” means. This subsection follows rather a philosophical approach with
quotes from renowned researchers who were or are still having a relationship to games
that will help with coming up with an acceptable definition for “game”.
“A game is something you play.” This is most likely the simplest form of game’s definition
but it does not give us any details rather than stating that it is something you play.
“A game is something that is fun to play.” is another definition everyone can agree on
which also includes the fun aspect. Understanding the building blocks of a definition is
as important as understanding the word you are trying to define, hence “fun” and “play”
need to be defined as well. Having “fun” is usually associated with having experiences that
give pleasure. However, “Fun is pleasure.” is alone not good enough because reading your
newspaper in the morning while having a coffee can give pleasure but it does not mean
19
2. State-of-the-Art
your morning routine is fun. Having fun with something requires that something involve
surprises [143]. “Fun is pleasure with surprises.” is a solid definition that distinguishes
fun from pleasure. “Play” is rather hard to express although we all know what play is
when we see it. The German playwright, poet, and philosopher Friedrich Schiller defined
play as follows:
Play is the aimless expenditure of exuberant energy. [48]
This definition expresses the outdated surplus energy theory [107] of play which claims
that the purpose of play is to expend extra energy. It also states that play has no goals,
which it most certainly does.
Early-twentieth-century philosopher Goarge Santayana describes play as “whatever is
done spontaneously and for its own sake” [112]. This definition makes sense to an extent
because play is often spontaneous when we describe the playfulness of a game. However,
that is not always the case when we think about competitive games. The participants of
competitive games have a long preparation time. Regardless of the competitive side of
plays, spontaneity is an important part of play. “For its own sake” part of the quote can
be interpreted as people do what they like to do. This is also an essential characteristic
of play because if we do not like to do it, then it is not play.
“Play is manipulation that indulges curiosity.” [141] by American video game designer
Jesse Schell is another definition for play that focuses on the curiosity aspect and the
willful action of changing something you are curious about.
Although none of these definitions explain play perfectly, it sheds light on various aspects
of what game can mean. Jesse Schell further defines game as follows:
A game is a problem-solving activity, approached with a playful attitude. [142]
This is a definition that covers many points of what a game can have and also makes
us aware that problem-solving should be playful since not every activity that involves
problem-solving is a game.
None of these definitions are perfect since it is a subjective topic, however now we have
a general idea of what game means. This subsection already sneak-peaked some of the
game design elements that are hidden in the definitions. The next subsection includes
these game design elements and more as it shows the categorization of them by different
views.
20
2.2. Game Design
2.2.2 Digital Game Design Elements
Developing a game starts with an idea that usually describes or hints about the game’s
core which can be described as a particular pattern of actions that repeats itself over and
over [110]. Expansion of the game’s core happens by adding some of the game elements
that are available in all games. This brainstorming process shapes the game with every
added game element that helps to design the game.
Before getting specific about game design elements, it is important to mention basic
elements that form a game. For this matter, there are different views with many common
elements. Andreas Alexiou et al. express in their work [4] that game mechanics, narrative,
and aesthetics form the main digital game elements. Game mechanics are procedures
and rules that are applied to the game that describes how players can or can not try to
achieve their in-game goals. These procedures facilitate the development of cognitive
skills such as problem-solving, creativity, and spatial skills [57]. Section 2.2.3 gives more
insight into game mechanics. A narrative or story is a series of events that unfold in the
game. With the help of the story element, players can construct reality and make sense
of the environment they experience [162]. On the one hand, branching and emergent
stories are not always the case while designing games, however, even in games where
storytelling is not essential such as in Pacman [183], it is still possible to at least guess
the reasons why their worlds are the way they are. On the other hand, a vast majority
of games rely on good storytelling to drive the game and to immerse players further
into the simulated worlds. Some adventure games prove the importance of story by
the success they achieved. “What Remains of Edith Finch” [36] is a great example of
an extremely successful story-driven game in which the player is playing as Edith, a
member of the Finch family, that discovers strange tales about her family members as
she traverses through the huge abandoned Finch house. Game aesthetics refer to the
sensory phenomena that the player encounters in the game [148]. In other words, it is
how games look, sound, taste, smell, and feel. Aesthetics count as a crucial aspect of
game design since they have the most direct relationship to a player’s senses [143].
Figure 2.11: The Elemental Tetrad [143]
21
2. State-of-the-Art
Jesse Schell adds the “Technology” element to the mentioned core design elements above
and describes these four core elements as “Elemental Tetrad” as seen in Figure 2.11 [143].
He states that technology does not always mean “high technology” but any tool and
interaction that can make the game work as it is supposed to. While choosing the right
technology enables your game to accomplish certain things, it also prohibits the designer
from doing other things. Moreover, it is also essential for these four core elements to work
in harmony and benefit from each other. When a set of game mechanics is considered to
be implemented, the technology should be able to support it. Additionally, the aesthetics
should emphasize these game mechanics clearly to players and the story should help the
mechanics to make sense to the players. For the sake of harmony, similar requirements
also apply to other core game design elements while characterizing them. The game
mechanics should strengthen the story, aesthetics should reinforce the idea of the story,
and the technology should suit how the particular story plays out. From the aesthetics
point of view, it is important to choose the right technology to provide and amplify the
certain look and feel that is planned to make players experience. A story with a set of
events lets the aesthetics emerge at the right place and have the biggest impact [3].
The core design elements can be further expanded such as George Kalmpourtzis did with
his “Elemental Pentad” [3]. Here, however, the design purpose of the game becomes
educational. Kalmpourtzis believes that the need of “pedagogy” as the fifth element is
highly required in the basic fundamental elements of educational games. In his design,
every other element should complement pedagogy directly and improve the experience
for its users.
Besides fundamental game design elements, there are many other digital game design
elements that can be included in games. The rest of this subsection covers some of these
elements while explaining what they mean and how they impact the game [143].
• Fun: Fun is a desirable element in nearly every game that increases the quality of
the game and the player experience. It is necessary to analyze the game during
playtesting to find the segments that do not give the feeling of fun. These parts
should be revised by questioning the reasons behind the lack of fun. Improving the
fun aspect of the game is essential because keeping the fun aspect at all stages of
the game gives that game an enjoyable flow.
• Surprise: Surprise is a crucial part of all entertainment and acts as a building block
for games. Since human brain is hardwired to enjoy surprises as research states
[144], it is an essential element to increase the enjoyment players can take from a
game. The previous subsection already mentioned this element while defining what
a game is. That alone emphasizes the importance of this element for games but it
is also necessary to understand how it can be triggered in various ways:
– The visual aesthetics in a game can be so incredible or one of a kind that
might exceed player’s expectations which can cause a pleasant surprise.
22
2.2. Game Design
– The player can learn a new in-game skill that can enhance their abilities to
move in the game and explore areas that seemed impossible to reach at first.
The capabilities this new skill gives to players can create a feeling of surprise.
– Horror games can contain unpleasant surprises such as jump-scares.
– Used technology can surprise players such as enabling interesting in-game
interaction techniques players could not think of.
– Game stories can end in unexpected ways which can surprise players.
• Curiosity: Curiosity is an element that has a direct impact on the player’s
motivation to play. The game should present players with compelling goals to reach
and give them reasons to reach those goals. As an example, setting a timer to
complete a challenge would plant the question “Am I going to be able to complete
this task in the given time?” into player’s minds and make them curious about the
result. Another way to keep player’s attention and make them curious would be
to condition them to receive rewards throughout the game and make them think
about what the next reward will be.
• Problem-solving: Problem-solving involves encouraging players to solve problems
in order to succeed at the game. Besides the obvious problems that are thrown at
players, there can be hidden or optional problems that need solving. Other than
enticing players to solve problems through critical thinking, creating additional
problems can attract more players. Some players are only interested in solving the
crucial problems and some other players, mostly completionists, do not hesitate to
spend extra time to find the hidden problems. This would also improve the time
spent in a game and make players keep coming back.
• Competition: Competition in games enables replayability of the game by giving
players something to improve on. Competition element can be added to a game in
two ways: The players can compete with themselves and improve their own scores
or achievements or they can compete with each other by beating each other’s scores.
Besides the replayability, competition also adds the socializing aspect to the game
if challenging one another is possible.
• Challenge: Challenges in a game make the game more appealing by giving players
the feeling of struggle towards a goal. However, it is important to mention that
badly designed games have little challenge, or too much challenge. If the game has
a little challenge it is highly possible that the player can lose interest in the game
very quickly. Too much challenge would also make the game unplayable for most
players and cause frustration instead of enjoyment. The games should have just
the right amount of challenge to be successful.
• Endogenous value: Greg Costikyan defines game as follows:
A game is an interactive structure of endogenous meaning that requires
players to struggle towards a goal. [58]
23
2. State-of-the-Art
The biological term “endogenous” shortly means “having an internal cause of origin”.
In his game definition, Costikyan means that things that have value in the context
of the game have value only inside of the game. This game design element as a
measurement describes how compelling a game is. The more compelling a game is,
the greater the “endogenous value” that is created within the game. So, increasing
the value of items or objects that are frequently used by players in the game also
increases their attention to the game and their will to play the game.
This section provided us with knowledge about digital game design elements a game must
or can include in itself. One of the fundamental game design elements, game mechanics,
however, needs more explaining, and therefore, the next section covers what is really
meant with game mechanics and gives details about some of its cornerstones.
2.2.3 Game Mechanics
Game mechanics are the interactions and relationships between the player and the virtual
environment that gives the game its soul [37]. This soul includes methods, rules, game
dynamics, goals, and actions players are allowed to take with the sole purpose of satisfying
the player by providing a compelling experience. The provided experience is received
in an endless cycle as long as the player keeps playing the game. This endless cycle
starts with the player interacting with a virtual environment that receives inputs from
the player and then changes its status based on the received inputs. The player, then,
analyzes these changes and makes decisions to take the next step in the game. This series
of actions become repetitive once the player interacts with the simulated world again.
Figure 2.12 visualizes this interaction cycle. The interaction cycle is moderated by the
Figure 2.12: Interactive cycle in the play experience by Fabricatore [37]
rules of the game. Since the interaction affects both sides, the player and the game, there
are different rules the player and the game itself should follow [17]. The rules the player
should follow can be a written set of rules which can be given to players before starting
the game or they can be introduced to the player as they progress in the game, or they
must be figured out by the player on their own. An example for such a rule can be the
requirements stated in the game to craft a tool. In such a scenario, the rules the game
should follow depend on the progression the player makes throughout the game. If the
24
2.2. Game Design
player has the correct amount of materials to craft a tool, the game should provide the
player with that tool.
So far this section gave the impression that game mechanics basically equal rules. On the
one hand, this approach is adopted by some researchers such as Lundgren and Björk [13].
They define game mechanics as “any part of the rules system of a game that covers one,
and only one, possible kind of interaction that takes place during the game, be it general
or specific (...) mechanics are regarded as a way to summarize game rules.” In this view,
game mechanics are accepted as low-level descriptions of game rules and there is no need
for a definitional distinction between rules and game mechanics. On the other hand, there
are counterarguments such as stated in Problem Machine Blog [98]: “A rule is a directive
of behavior that must be observed for the game to proceed. Conversely, ‘mechanic’ is
distant and impersonal, implies something that happens as a natural consequence of
something else occurring.” This view sees rules as intimate, as they require the player to
actively participate in order for the game to continue which also requires the player to
have an understanding of rules. In comparison, game mechanics are impersonal which
means that they do not require player participation or game understanding by the player.
Although rules are the most fundamental of all game mechanics and they give the game
its identity, the rules alone do not define the game mechanics of a game. Skill is one of
these elements where every game requires players to exercise certain skills. Based on the
player’s skill level a game can feel challenging and give something to work towards for
the player. Skill is also a source of enjoyment for players as long as it stays interesting,
rewarding, and balanced for different skill levels of players if the game possesses these
characteristics. Chance is another element of game mechanics. Leaving certain outcomes
to luck is a great way to create surprises. As mentioned in Section 2.2.1 surprise is one
of the most important game design elements that bring joy and excitement to players.
Since game mechanics is a part of the game design elements, all of its cornerstones can
be further added to the list of other game design elements mentioned in Section 2.2.2.
The next section emphasizes the playtesting step in game development and how it affects
the changes made for planned game design elements.
2.2.4 Playtesting
Playtesting is one of the most important development steps during game design. It can
be described as a form of a usability test where the tester can observe how players read
and react to the game. It is always better to start playtesting as soon as possible. The
time a prototype of the game is available the designer should start with playtesting.
Since every comment from playtesters is crucial to improving the game, both positive
and negative feedback should be embraced. While positive feedback signals that the
designer has done something appealing, negative feedback makes the designer rethink the
validity of that specific part in the game. Although positive feedback is good to hear and
25
2. State-of-the-Art
important to build up confidence, negative feedback includes essential information about
improving the game further. The tester should not hesitate to ask playtesters what is
wrong with the game and explicitly encourage them to be as brutally honest as possible
while giving feedback [132].
Another key point is choosing the playtesters carefully. Friends and family are good
starting points to test the game prototype with, however, their feedback will most
probably be biased due to the relationship. Sticking to only relatives as playtesters can
cause missing major flaws in the game, hence seeking people that can give honest and
constructive feedback is a major step to receive the information needed to revise the
game.
Welcoming negative feedback is one thing, but adapting your ideas according to feedback
is another. Taking negative feedback to the heart can ensure you do not get too attached
to the specifics of an idea [132]. The same goal of an idea can be achieved in other ways
which can also improve the game at the same time.
Playtesting has a direct relationship to the game design elements that are included in
the game. This enables playtesting to examine the game on multiple levels. On one level,
as an example, the game needs to have the right amount of challenge and be balanced. If
the game feels too difficult to play for a playtester which, however, can not be the case
for everyone, the tester can ask questions about the parts that make the game difficult
for that playtester. The received feedback can help rebalance the game for the casual
audience. On a higher level, a playtest can reveal how the players react to a game’s theme,
and whether the theme fits the mechanics [121]. If we continue with the balance example,
this higher level can be achieved if the changes made in lower levels mean something
within the game. Stardew Valley’s [24] building crafting mechanics is a concrete example
for creating balance with numbers and making these numbers meaningful within the
game. If the player wants to build the lowest tier barn, one set of resources the player
needs to provide is 350 pieces of wood. In comparison to this, a higher-tier barn requires
500 pieces of wood instead. This higher-tier barn allows the player to house more animals
in it. It is fine to think about the required number of resources just as a numerical value
but it also makes sense because building a bigger barn would logically need a lot more
pieces of wood. Moreover, playtesting can reveal if the game is fun, and can assist with
finding out the correct audience for the game. Fun is a subjective term, therefore different
groups of playtesters will have fun in different ways. However, different views can help
the designer narrow down the audience and pitch the game to the players who will like it
most. Given examples in this section show that various game design elements can be
tested through playtesting.
The next subsection is a brief reflection of previous subsections: game design elements, and
game mechanics on VR which informs about limitations, advantages, and disadvantages
of VR while applying the mentioned points to VR.
26
2.2. Game Design
2.2.5 Reflection on Virtual Reality
Immersive VR experiences are basically illusions during which users may experience
being in another place where the events taking place are real [165]. In addition to place
and plausibility illusions, embodiment illusion is another tool to make the experience
more immersive [103]. To achieve this, an avatar body can be used in the virtual world
that can represent player’s physical body. These illusions are the main power of VR that
fools the brain into believing that the artificial environment and the events occurring in
it are real. As long as these lies are believable players can live these experiences without
breaking the illusion and they can experience them in person. Experiencing events or
the environment in person is the most distinguishable feature VR games provide in
comparison to games played on PCs and other similar screen-based platforms. However,
the illusions are both the strength and the weak point of VR. While it is hard to create
illusions that satisfy players, they can be easily broken. The human brain is good at
noticing unusual events and if the created illusion does not make sense with the way the
virtual world is presented, the illusion can result in breaking the immersion.
Figure 2.13: Content-zone diagram for a comfortable user experience [5]
Since VR is still a developing technology, one must take the capabilities of the system and
the people using the system into consideration. It is essential to understand the limitations
the hardware brings and how it can affect users. Once these technical limitations are
recognized and necessary measures are taken, the next step is understanding users and
the issues that may come up during their VR experiences. There are various ways to
solve these issues or prevent them from happening. One of them is providing users with
physiological comfort. If the game includes too much movement, it should be controlled
by the player to prevent motion sickness. Section 2.2.7 goes more into details about the
causes and solutions for it. Another key point is providing spatial comfort to players. This
27
2. State-of-the-Art
perk is directly related to understanding the scaling in the virtual environment. Players
may get uncomfortable due to small, large, or high spaces. Guiding players through the
environment is another important aspect to keep player’s focused and prevent them from
having the feeling of getting lost in the environment. Audio and light support can be
used to reveal paths in order to direct players into the directions they are supposed to go.
The same guidance methods that have proven successful are used while designing other
non-VR digital games. If the game includes UI elements it is essential to take ergonomics
into account. Alger et. al describes the comfortable range of motion zones in their work
[5] which are illustrated in Figure 2.13 and Figure 2.14.
Figure 2.14: Comfortable angles of neck rotation [5]
Sound is another tool used in VR to increase immersion and create the phenomenon
of synesthesia [49] in order to make up for the lack of tactile feedback in VR. Since
tactile feedback mostly consists of vibrations that are coming from the VR controllers,
sound is a great tool to enhance the feedback players receive when they touch objects.
Besides combining haptic feedback with sound, providing holophonic sound is great to
have because, in addition to left and right channels in stereophonic sound, holophonic
sound allows players to tell if sound is coming from above, below, or behind [19].
Since the player is the center point in VR and present in the virtual environment, artificial
sensory sensations such as visual, auditory, and haptic feedback should be provided as
much as possible to make the player feel more like a part of the environment. Although
providing visual and auditory feedback in games is at an acceptable level to make
things feel real to players, other sensations lack or are non-existent for VR experiences.
Sensations such as equilibrium [159] and olfaction remain unaffected partly because of
their unavailability in general or inaccessibility to the end-user.
28
2.2. Game Design
Although non-VR games can create immersive experiences, it is hard or not possible for
them to reach the immersion level of a VR game can provide to its users [129]. Because
of the way VR affects its users, the usual game design elements and game mechanics have
to go through some alterations to be as effective in VR. The ideas that create the game
design elements must adapt to the limitations and possibilities VR lays out to improve
the user experience.
Immersion is mentioned in this subsection and previous subsections many times so far. It
is essential to understand what it really means and why it is important for VR. The next
subsection informs about immersion and its types to give an in-depth understanding of it
for game design.
2.2.6 Immersion
Immersion is the user’s engagement with a VR system that results in being in a flow
state [10]. This is a simple definition of immersion, however, it encompasses so much
that its components need to be explained further. Staffan Björk and Jussi Holopainen
proposed different types of immersion in their work which can be listed as follows [13]:
• Spatial immersion
• Emotional immersion
• Cognitive immersion
• Sensory-motoric immersion
Björk and Holopainen described spatial immersion this way [12]:
Spatial immersion occurs when the simulated world is perpetually convincing.
The player feels as if he or she is really “there” and that the simulated world
looks and/or feels “real”. (...) Spatial immersion as such is the real result of
extensive maneuvering in the game world in real-time games and can even be
occasionally felt in movies as well.
The VR experience offers a new way to exist in the virtual world as a spatial presence and
keeps the simulated world as Björk and Holopainen mentioned “perpetually convincing”
with the help of encapsulation of head-mounted-display (HMD). The HMD serves as a
remedy to immersion disconnects since users can stay connected to the virtual world as
long as the HMD is worn. However, wearing an HMD is not the sole solution to these
disconnects because technical factors and in-game implementations such as reconfigurable
game worlds or invisible walls can cause further disconnects [97]. Locomotion is another
major point as the player may have to traverse the simulated world. As previously
mentioned in Section 2.1.3 there are many ways to achieve this in VR, however, the
preferred way needs to feel natural and fitting to the world’s reality logic.
Björk and Holopainen’s take on emotional immersion is as follows [12]:
29
2. State-of-the-Art
Emotional immersion is obtained by responding to the events that characters
are part of during the unfolding of a narrative structure and is like the
immersion that books, theater or movies provide.
Most VR games tend to have a narrative side to the gameplay regardless of their genre
because it helps the player feel more involved and more immersed in the game. As in
any type of game no matter what platform the game is played on, the game’s story can
evoke positive and negative emotions. Pallavicini et al. concluded in their study [120]
that VR games appear to be effective tools to elicit positive emotions and to decrease
negative emotions and state anxiety in individuals. Although this effect of VR is possible,
it is also proven that VR content may lead to strong and persistent negative emotions
[93]. The same study further found out that VR enhances the level of absorption into
the scenario and creates more intensive emotions compared to games played on non-VR
platforms.
Cognitive immersion is the immersion in abstract reasoning about actions, events, and
goals in games while playing the game [167]. Freedom of choice is the only requirement
cognitive immersion has which makes players consider what actions to perform throughout
the gameplay. Cognitive immersion depends heavily on providing the right level of
difficulty which can be achieved by providing consistent reality logic [168]. Consistent
reality logic can regulate having the right amount of difficulty by removing the need to
have to deal with special cases within a complex environment. If the difficulty is not
balanced correctly, low or high-level complexity may cause players to experience analysis
paralysis [169] or downtime [170] which would result in players losing interest in the
game.
Sensory-motoric immersion is the result of feedback loops between repetitous movements
players make to perform the actions in the game and the sensory output of the game [97].
When a player performs an action in a game, the available visual, auditory and haptic
response that emerges has to be synchronized and make sense with what the player would
expect from that action. If the sensory response does not match the expectations at all,
it may cause a disconnect in immersion. Sensory-motoric immersion is tightly coupled
with cognitive immersion in terms of correct use of complexity in the game. Keeping the
player feel challenged continuously would ensure and maintain sensory-motoric immersion
[97].
Keeping the immersion intact in VR games at all times has the highest priority to keep the
players interested in the game, thus, providing them with a high-quality experience. As
mentioned in this and previous sections it is not always easy to keep the high immersion
level up from a design and technology viewpoint. The next section adds another problem
to the list of issues to solve while gaming in VR: motion sickness.
30
2.2. Game Design
2.2.7 Motion Sickness
VR motion sickness is primarily caused by a mismatch between movement cues sent
to the brain. If the user is standing still in the real world but the virtual environment
around the user is moving, this disturbs the brain’s equilibrium and the user starts to
feel nauseous. Nausea and dizziness count as the most common symptoms of motion
sickness in VR [163]. Since VR motion sickness is also categorized as simulator sickness,
there are other symptoms such as headaches, feeling tired, eye fatigue, and disorientation
[20]. There are also additional factors that can influence the occurrence of VR motion
sickness in individuals. A study shows that women are more susceptible than men to
experience nausea in VR, which can be explained by women having a wider field of view,
hormonal differences, or different in-depth cue recognition [18].
There are various factors that influence VR motion sickness. These factors can be divided
into two categories as technology-influenced and design-influenced factors [163]. One of
the technology-influenced factors is the headset that is used for tracking the position of
the player. First released 3-degrees of freedom tracking (3DoF) headsets did not provide
free movement and were only good for viewing 360-degree videos. In case the user tries
to move around with a 3DoF headset, the user would feel disorientation and unbalance
because the scene would not move with the user. Compared to the 3DoF headsets, 6DoF
headsets provide freedom of movement within the virtual environment and solve motion
sickness problems 3DoF VR headsets would create. Using VR controllers is another factor
that helps with reducing motion sickness. Having hands in the simulated environment
reduces the effect of disorientation which can be caused by looking down in VR and not
seeing anything the user would normally expect. Latency is another technology-driven
aspect that affects motion sickness. Oculus made intensive research on the topic [40] to
figure out the comfortable delay people can accept between the actions they take in a
real-world environment and the representations of their actions seen and heard in the
simulated world without causing motion sickness. Gaze behaviors also affect motion
sickness in VR. The unfamiliar eye motion that is required to keep the virtual scene
stable on the human retina cause this unwanted effect [21].
Design-influenced factors mainly focus on problems that come with rotation and locomo-
tion in the virtual environment. As previously mentioned in Section 2.1.3 teleportation
is a way for players to traverse the environment. It is proven that teleportation helps
reducing motion sickness [30] in games. The way it works breaks the illusion, however, it
keeps players moving through the world without tricking their mind into thinking they
are walking. Besides teleportation, running in place [74] and redirected walking [90] are
other ways to move in the virtual world without creating any conflict between the sensory
and vestibular systems. As much as these methods eliminate the occurrence of motion
sickness, these methods are not preferred in games possibly because of the additional
space requirements and forcing players to physically move most of the time. There are
other tricks learned by the developers that using static artwork or controlling where the
player focuses their attention decreases motion sickness [156].
31
2. State-of-the-Art
Motion sickness is still a key topic for VR and it is a major problem to be solved in order
to increase the number of VR users. With the information given about motion sickness
in VR, this subsection concludes the game design part of this chapter. Besides VR and
game design, the designed game for this work immensely focuses on climbing. Therefore,
climbing in general and especially in VR need to be clarified which is presented in the
next chapter.
2.3 Climbing in Virtual Reality
2.3.1 Traditional Indoor Climbing
Although this subsection is dedicated to climbing in VR, one should have a knowledge
base about climbing in general since virtual climbing is based on traditional climbing
at its core. There are three main points climbers have to accustom themselves to: the
equipment they have to wear during the climb, the rope system which acts as a safety
measure during the climb, and the technique they need to adopt to make the climbing
experience easier and safer [184].
Indoor climbing presents the climber with the opportunity to climb in a controlled
environment with extra safety measures. Non-wearable equipment can include mats on
the floor to provide a soft landing in case of a fall accident, carabiners on the walls to
which climbers can attach themselves as they progress further up, and chalk to remove
moisture from hands and ease gripping the handholds. Wearable equipment mainly
consists of a harness that combines a waist loop and two leg loops tied together, and
special climbing shoes that give more edging power to the climber as seen in Figure 2.15.
In addition to non-wearable equipment, the climber has to have a partner also called
belayer to hold them. The belayer should be very careful and pay attention at all times
to catch a fall every time the need arises. Climbing shoes are usually advised to be worn
without socks because during climbs with small climbing holds, the foot-to-shoe contact
matters a lot more due to additional grasping power [184]. For the climbing systems that
are based on climbing high, the climber needs to be belayed. As mentioned before, this
means that someone is belaying the climber on the ground, and the rope that is attached
to the climber’s harness via carabiners passes through an anchor fixed on the wall and
clips into the belayer’s harness as seen in Figure 2.16. Moreover, it is also recommended
to make the climber let themself go in the early stages of the climb to get a feeling for
falling and build trust with the belayer. Another option is to use an auto-belay [59], a
device that is anchored to the top of the wall and automatically takes up slack as the
climber climbs. This method is usually recommended for beginners because it allows
beginner climbers to focus on only climbing without worrying about whether the belayer
is doing their job properly.
Climbing technique is something that needs to be learned by the climber with experience.
Professional climbers suggest climbers look at their feet instead of their hands during
the climb and plan their moves based on them. Climbing should be about walking
32
2.3. Climbing in Virtual Reality
Figure 2.15: Harness and climbing shoes for in-
door climbing. [150]
Figure 2.16: Rope system
setup for indoor climbing.
[9]
yourself up instead of pulling yourself up [184]. Adopting this move-set also reduces
forearm fatigue along with holding arms straight as much as possible while not using
them actively. Keeping hips over feet as much as possible and the torso close to the wall
are further suggestions to stay strong and in control of your movements because your
center of gravity stays in the middle of your body this way.
Mentioned points summarize the key elements during a climb in a real-world scenario. The
next subsection takes a look into how climbing in VR is achieved by various applications
so far and how much of the information given in this subsection affected the design of
these scenarios.
2.3.2 Virtual Climbing
With the advent of VR in the commercial scene, VR sports games also became popular
among consumers. Archery, fishing, bowling, dancing, and climbing are some of the most
notable sports that made into VR. This subsection, however, will focus on the climbing
games which is a focus point for the developed game Astroclimb.
33
2. State-of-the-Art
Figure 2.17: What competition looks
like in The Climb 2. [25]
Figure 2.18: The climber’s vertical move-
ment on the wall is mostly restricted. [81]
The Climb, developed by Crytek for Oculus Rift and The Climb 2, developed for Oculus
Rift and Oculus Quest, are two memorable VR climbing games that made a positive
impact on the market. The games are characterized above all by appealing and realistic
aesthetics. There is a wide variety of landscapes such as snowy mountains, city with
skyscrapers, and desert areas players can climb in. The game focuses on enabling players
to climb dynamically and quickly on certain routes. It is possible to compete against
friends and have their position visible as additional ghostly gloves climbing with you
as seen in Figure 2.17. In order to control the avatar hands, players have to use the
corresponding controllers Oculus Rift and Oculus Quest provide. The game’s haptic
feedback is limited by the signals the controllers can issue to players. Since there are no
other body representation models in the game and the virtual world is not supported by
any physical objects in the real world, the climb happens only with the player’s hand
gestures and arm movements. These characteristics also make it clear that no measures
like the ones mentioned in the last subsection are needed.
There are other similar games such as To The Top [154] which combines climbing with
the platformer genre and Lucid Trips [153] that focuses on exploring surreal environments
with a bit of climbing in them. As in The Climb series, these VR games provide players
only with in-game hand representations to be able to move around. Just like in The
Climb, VR controllers are the equipment here to control the avatar hands in artificial
environments. Kosmalla et al. investigated in their research [25] the common issue
in these games, the missing feedback when interacting with virtual objects, to enable
realistic, haptic feedback in a realistic-looking virtual world. In their application, they
used an artificial climbing wall as a haptic feedback device. The climbers have to use a
head-mounted display with Leap Motion Controller [166] attached to be able to move
in the virtual environment and have their hands tracked at the same time. This setup
allows climbers to actually climb on the physical climbing wall to be able to traverse
the virtual mountains. Since the physical wall has a height of 2.5m, there were not any
safety measures such as the use of ropes or harnesses. As Figure 2.18 shows, the climber
34
2.3. Climbing in Virtual Reality
(a) SteamVR Base Station 2.0 (b) HTC VIVE Pro Headset (c) VIVE Tracker
Figure 2.19: VR equipment used for Astroclimb. [176]
is mostly encouraged to move sideways.
This subsection already mentioned some of the equipment used when it comes to climbing
in VR, however, there are still other options in terms of equipment. Section 2.3.3 focuses
on the technologies used for Astroclimb while including some of these other options.
2.3.3 Virtual Climbing Technologies
Section 2.1.3 already mentioned some of the well-known technologies for VR, however,
this subsection goes more into technical details and the purpose of HTC VIVE Pro, VIVE
Trackers, and the calibration algorithms for the developed VR game Astroclimber.
HTC VIVE Pro
HTC VIVE Pro is a commercially available head-mounted display for generating virtual
reality via connection to a PC. Here is a list of some of its most important features [145]:
• Resolution: 1440x1600 pixels per eye (2880x1600 pixels combined)
• Field of view-headset: 110 degrees
• Field of view-base stations: 150 degrees
• Refresh rate: 90 Hz
• Screen: Dual AMOLED 3.5” diagonal
• Sensors: SteamVR Tracking, G-sensor, gyroscope, proximity, IPD sensor
• Room-scale: Up to 10m x 10m trackable area using four SteamVR Base Station
2.0
35
2. State-of-the-Art
HTC VIVE Pro headset has some comfort upgrades which were missing in its predecessor
HTC VIVE. The VIVE Pro includes a solid strap, integrated headphones, and a comfort
system that consists of a dial at the back of the headset which allows for easy fit
and comfort adjustment. Besides these improvements, VIVE Pro also has enhanced
ergonomics that balances out the weight of the headset for game sessions. Astroclimb
uses VIVE Pro to track the position of the player on the wall. The tracking also includes
the use of 4 different base stations. The base stations emit wide-angle two-dimensional IR
laser beams across the play area. Each tracked device contains an array of IR photodiodes
connected to a chip. This chip measures the time between the IR flash and being hit by
the laser sweep for each axis. From this received information, the position of tracked
objects can be determined. Astroclimb uses four strategically placed SteamVR Base
Station 2.0 for tracking.
VIVE Tracker
The VIVE Tracker is a small motion tracking device that can attach to any object
in real life so that it can be tracked via the base stations. It has a 270-degree field
of view for sensing the SteamVR Tracking base stations. The bottom part of the
device deliberately avoids using sensors with the expectation that it will be mounted
to something. Moreover, objects should be made of non-reflective material to maintain
maximum tracking performance, presumably to avoid reflections from the tracking lasers
which could confuse the device or even the VIVE headset while in use [175]. Astroclimb
uses a total of eight VIVE Trackers, half of them mounted on the wall to track the wall’s
rotation, two of them placed on the player’s hands and the other two for tracking the
feet.
Calibration
Astroclimb includes two different calibration procedures that take place at the start of
the application. Both calibration algorithms are implemented by BSc. Ahmed Othman
as part of the Vreeclimber project [35]. The first calibration process calibrates the
positioning of the hands and the feet of the player. For that to happen, the player has to
wear two trackers on top of their hands, and two of them on top of their feet. Once all set,
in a standing position, the player should keep their toe tips and fingertips facing forward.
In addition to that, their palms should be parallel to the ground. Figure 2.20 shows how
the player’s stance should be during the hands and feet calibration process. The second
calibration process involves aligning the physical wall and its climbing holds with their
virtual representations in the virtual environment. In order to achieve this, there should
be two visible trackers mounted on the wall on one side. Based on the distance between
the headset and these two trackers on the wall, the position of the headset is adjusted
which results in aligning the wall. This concludes the initial calibration process for the
wall. Since the physical wall keeps rotating during the game, the position of the climbing
holds change with varying speeds. With the speed information gained from the engine
that makes the wall rotate and the position information acquired from tracking the wall,
36
2.4. Related Work
Figure 2.20: The stance the player has to take for calibrating hands and feet.
the climbing holds’ positions on the wall update themselves via the algorithm which
keeps the climbing holds aligned with their representations in the virtual environment.
2.4 Related Work
As mentioned in previous sections, the decisions game developers make to design the game
and meet the users’ expectations highly depend on the state of the current technology.
Moreoever, game design in VR is still a playground for game designers and developers
considering the impactful growth of VR in game industry only happened in the previous
decade as mentioned in Section 2.1.1 and 2.1.2. Therefore, the fusion of game design and
VR will still take time to be in harmony and appealing to users. This section introduces
other related research papers that focus on game design in VR.
Shelstad et al. investigate in their research [146] how VR technology impacts the game
as user satisfaction by using the Game Use Experience Satisfaction Scale (GUESS) [123]
which is a comprehensive and psychometrically validated game scale that includes nine
subscales contributing to video game satisfaction. These subscales consist of various
game design elements some of which are already mentioned above. They can be described
as follows:
• Usability/Playability: This subscale describes the ease of control inside of the
game for the player and whether the game has clear goals for players to fulfill.
• Narratives: This is the story aspect of the game that can have an influence on
player’s emotions towards the story elements of the game which is also responsible
for keeping players interested in the game.
• Play Engrossment: This perk describes the degree of interest a game can hold
for the players.
• Enjoyment: The fun factor describes the pleasure players can perceive by playing
the game.
37
2. State-of-the-Art
• Creative Freedom: This is the extent to which the game is able to foster the
player’s creativity and curiosity and allows the player to freely express his or her
individuality while playing the game.
• Audio Aesthetics: This subscale includes all auditory aspects the game offers
and how they enrich the gaming experience.
• Visual Aesthetics: These include the visuals in the game and how appealing
they appear to the player.
• Personal Gratification: This perk involves the motivational aspects of the game
such as challenge which can promote the player’s sense of accomplishment and the
desire to succeed and continue playing the game.
• Social Connectivity: This subscale describes the degree to which the game
provides social interactions between players with its tools.
Although GUESS represents a broad scaling tool for measuring player satisfaction, the
research states that there should be doubts about its evaluation simply because of the VR
aspect of the games. Considering VR provides a richer and more immersive experience,
GUESS scores should vary for a game played using VR and no VR.
Furthermore, the study shows that some of the game design elements listed under GUESS
subscales are successfully applied to VR gaming experience and there was a significant
difference in the overall satisfaction scores between the VR and traditional computer
monitor experiences.
Nolan et al. emphasize in their study [114] player experience, comfort, and design processes
that are important while designing games for VR. They point out the importance of
player comfort and categorize it under physical, psychological, and social comfort. While
physical comfort focuses on the orientation and the movement of the player in the virtual
environment, psychological comfort states that the VR experience should refrain from
trauma-inducing and unpleasant content. If the game includes social aspects, it should
include safe zones and places for players to rest and potentially remove their headsets to
get out of that social environment to recharge. Section 2.2.5 of the thesis prioritizes the
physical comfort aspect of player’s comfort in general and provides in-depth knowledge
about what Nolan et al. mentioned in their research.
Besides player comfort, the study directs attention to the possibilities and limitations
of VR as well. These possibilities and limitations include the interaction techniques in
VR, player expectations, tracking, and locomotion methods. These subjects also create
an essential part of the thesis that is mentioned in Section 2.1 and 2.2. VR playtesting
is another topic of Nolan et al.’s research which states the importance of it and what
should be taken into account while performing playtesting. Section 2.2.4 of the thesis is
specifically related to this topic.
38
2.4. Related Work
Immersion and Engagement in a VR Game by Pradeep et al. [127] is another work that
involves VR and game design. The researchers compare the levels of user engagement and
task performance based on a VR game. The study furthermore focuses on a comparison
between desktops and the HMDs and explores exocentric versus endocentric approaches,
the level of confusion factor, and the effect of the virtual avatar representations. During
their observations, they also take note of the situational awareness of the user when they
play the game. The goal of the study is to answer the following questions:
1. What is the level of engagement that the user experiences?
2. What is the task performance and time elapsed for the task for each user within
the designed time?
3. What path does the user take to complete the task?
As seen in the questions they used some specific game design elements such as engagement,
problem solving, and player performance to get answers.
Alexander Lund’s paper [97] investigates immersion, game feel, and flow states for VR,
and how these elements can either enhance or reduce the quality of player experience.
In order to support the investigation, the researcher makes use of a story-driven VR
experience called Norn [96]. The paper includes a large variety of different types of
definitions for immersion which also inspired Section 2.2.6 of the thesis. The author
emphasizes that the mechanics and interactions designed for a VR game should feel
natural to perform and should not be taxing for the players during extended play sessions.
The designer should, moreover, keep the VR equipment and the in-game interactions
in mind while designing the game around them. As in previously mentioned papers,
Lund points out the significance of the player’s physical comfort while playing the game.
Besides these points, world and player scaling form a major part of his work. According
to Lund, the game should be designed for the physical space provided. The locomotion
in this designed area should feel safe and should not cause disconnects between the
time before and after the teleportations if that is the chosen locomotion technique for
traversing the virtual environment. Various sections of the thesis include knowledge
about most of these key points mentioned in Lund’s work.
Desurvire et al.’s research paper [28] is another example that focuses on VR and game
design. They created in their study design guidelines called the VR PLAY guidelines to
assist in evaluating and designing improved VR user experiences. VR PLAY guidelines
consist of five main categories called Usability, Playability, VR Immersion, Creative
VR, and New Player Experience (NPE). These five main categories have a total of 33
guidelines which includes some of the mentioned game design elements in the thesis
such as challenges, goals, engagement, and presence. As Desurvire et al. state, not all
guidelines are applicable to all VR experiences because the created VR experience may
not contain certain common game mechanics to which these guidelines apply. This is
another commonality with the present thesis that a game can not contain all possible
game design elements.
39
2. State-of-the-Art
Although the presented related works in this subsection vary by their questions to answer,
the common point is providing a compelling user experience to the user within the
designed VR game. The next main section goes more into details about the designed VR
game for the thesis starting with the conception of the game.
40
CHAPTER 3
Conception of Astroclimb
3.1 Requirements for Designing the Game
There were various requirements for designing Astroclimb which branch out from the
thesis questions. This section is the starting point to explain these requirements that led
to creating this specific concept of the game. A brief list of the main requirements would
be appropriate before explaining them in detail:
• The game should revolve around climbing a wall.
• The gameplay should be as flexible as possible to address a diverse gameplayer
base.
• The game should be immersive and compelling.
• Included game design elements should match the VR aspect of the game.
While designing the game, the main focus was making the game as flexible as possible
in terms of gameplay while keeping in mind that the game includes a physical climbing
wall. Taking advantage of the climbing aspect of the setup, the conception of the game
creates a clear distinction between the experience a player can have while playing a VR
and a non-VR game. Astroclimb makes the player interact with objects as much as
possible while giving haptic feedback which is one of the main distinctions of this VR
game compared to traditional video games. The idea of in fact climbing a physically
present wall also enabled physical training for the players. Enabling physical training in
a playful way was another feature of the game that distinguishes this game from other
video games and even most VR games. These features of the game were to create a
basis to investigate the applicability of game design practices to VR platforms. Applying
common game design practices to a VR game with these features would create a fair
41
3. Conception of Astroclimb
testing environment and help with answering whether these methods are appropriate for
VR experiences or not.
In order to keep the game immersive and compelling to the players at all times, the
use of technology played a crucial role in addition to the aesthetics that are used for
creating the environment. Especially the calibration algorithms used to keep the physical
objects aligned with their virtual representations contribute to the level of immersion
significantly. The technology and the aesthetics directly influence the game feel. Game
feel is a combination of different aspects which include tactile sensation that dictates
how entertaining or engaging the act of playing the game is, how quickly the character
responds to control input and how much audio and visual feedback it is provided for doing
something within the game [157]. In addition to audio and visual feedback, Astroclimb
also provides haptic sensations which enhances the game feel.
The gameplay in Astroclimb has a substantial influence on the chosen game design
elements. Since the game mainly revolves around climbing a wall, most of the game
design elements such as problem-solving, elements of surprise, physical training, fun, and
competition have a direct relation to what the player is capable of doing in the scenery.
As previously mentioned in Section 2.2.5 VR comes with limitations and possibilities,
hence the application of the game design elements required adaptations based on the
physical availability of the players and other aspects which are discussed later in Section
3.3 in detail. The next subsection goes into detail about the chosen design approach to
create Astroclimb.
3.2 Design Approach
The game design idea is mostly affected by the structural design of Vreeclimber. As
previously mentioned in Section 1.2 Vreeclimber’s structure is based on a vertically rolling
wall that can enable climbers to climb indefinitely. The physical structure needed a
virtual representation in the artificial environment, so the first steps were designing a
wall with climbing holds on them that match the physical wall as perfectly as possible.
The height of the wall and the material used for it were the most crucial points during
the design process of the virtual wall. On the one hand, the height of the virtual wall
has a measurable influence on the usability and game feel. A very high wall could reduce
the usability for some players that are not used to climbing. This would additionally
affect the game feel in a way so that the players might just give up in the middle of
the game because their physical endurance for climbing could not match the strength
required to finish the game. The playtesting sessions also showed that the initial height
of the designed virtual wall was too much for most players so the number of grip blocks
got reduced during the development. On the other hand, the height would also affect
some of the game design elements such as physical activity and engagement in a negative
way. Again as an example, a higher wall might cause the application of the physical
activity element to be unsuccessful by creating an exhausting experience. Making the
42
3.2. Design Approach
game physically not enjoyable would also take away the engagement aspect of the game
and render it unappealing.
The chosen material for the virtual wall also plays a key role in designing the game.
Creating a fully transparent material for the virtual wall makes up for some of the
disadvantages of climbing a regular wall while enhancing the visual aesthetics of the game.
If the virtual wall were opaque, that would mostly limit the view of the climber with side
directions during the game besides seeing the wall. As previously mentioned in Section
2.3.1 climbers usually focus on their hands and feet during the climb which means their
focus of direction to the front. Focusing on what is in the front would also make the
objects placed behind the climber not or hardly noticeable. Giving a transparent wall to
the player and populating the backside of the virtual wall with interesting objects would
improve the visual aesthetics of the game. Since the player’s front view is mostly the
focus point in such a case, this would also reduce the additional head movements the
player has to perform in order to be able to see the environment. These quality of life
improvements in the game would help players with regulating their stamina during the
climb efficiently and reduce possible causes for motion sickness.
The root idea of designing Astroclimb in outer space comes from the discussions during Ms.
Natascha Machner’s master’s thesis [99] defense. Climbing in outer space is something
that would not be possible at least with the technology we currently possess. The
combination of this impossibility and the unknown knowledge that lies in outer space
encourage humankind to fill this knowledge gap [147]. This curiosity inducing hunger for
information makes space an excellent theme for games. The high number of outer space
related games on Steam [152] emphasizes the popularity and success of using outer space
as a game environment.
The idea of having a climbing wall in outer space automatically adds the science-fiction
genre to the game which also opens many doors for creativity. In comparison to science-
fiction, sticking to reality would limit the design options especially for a game that is
played in outer space. Although designing a game with an unrealistic setup gives freedom
about ideas to the designer, it also adds the challenge of making the game immersive. It
is important to design the environment in such a way so that the setup can make sense to
the player and the player can still immerse themselves in it. In this matter, Astroclimb
provides the needed immersion with different aspects it possesses such as aligning the
physical and virtual objects at a high level, having futuristic-looking objects, matching
soundtracks and effects, and a story that makes sense to players. All of these aspects of
Astroclimb with the given gameplay options create a game feel that aims to satisfy the
player.
The design evolution of Astroclimb went through some changes to match the previously
mentioned requirements for designing Astroclimb better and improve the experience
players can receive from the added game design elements. Besides changing the height of
the virtual wall, the way of keeping players safe and preventing them from reaching the
43
3. Conception of Astroclimb
very top of the physical wall was altered. Since the physical wall has a certain height and
the virtual wall is taller than the physical one, it is a common occurrence that the player
reaches the top end of the physical wall during the climb. When this happens, for safety
reasons, players have to pause climbing until the wall rotates long enough for players to
slide back to the planned climbable area of the wall. The first idea was to add a thick fog
to the top border of the climbable area and make everything above that point invisible.
After numerous playtesting players still tended to reach to the climbing holds above the
fog although they did not see them which showed that fog was not an adequate solution.
Furthermore, the fog prevented players from seeing some of the gameplay cues such as
an asteroid hitting the top of the wall causing the wall to tilt. An alternative way was to
give the player a virtual astronaut helmet and use its glass surface for displaying warning
texts and information. The warning text is also supported with audio feedback. The
playtesting afterward showed that the alternative solution encouraged players to pause
climbing when they saw the warning text. Another improvement to motivate players to
replay the game was a change made in the gameplay. The next subsection goes more
into the game design elements Astroclimb possesses and explains how they are achieved
in the game to give players an engaging gaming experience.
3.3 Included Game Design Elements
Astroclimb’s conception includes various game design elements. Section 2.2.2 lists only a
subset of the game design elements that were actually used in the present game. Those
game elements and the additionally included ones are listed below:
• Experience: The main goal of Astroclimb is to give players an experience they
can not receive anywhere else by climbing a celestial wall in outer space while they
can enjoy the environment and the events occurring throughout the climb. The
story of the game, the aesthetics used to build the environment, the mechanics
provided to players, and the unique playstyle VR technology creates help to define
the essence of Astroclimb and bestow it upon players.
• Surprise: Astroclimb injects this game design element in various ways. Some
of them just come with technology such as the precise tracking system for the
player’s hands and the high-resolution perk of the used headset which renders the
environment as if it was real. Game aesthetics such as giant spaceships warping in
and out all of a sudden, the sound of an asteroid crashing the wall, and the whole
climbing wall getting sucked into a black hole are a couple of examples that create
a sense of surprise for players when they experience these events. The gameplay
also contains some unexpected events such as touching a relatively smaller climbing
hold gives extra points.
• Curiosity: There are many ways Astroclimb awakens the feeling of curiosity in
players. The way they are injected into the game is mostly through visual aesthetics
and game mechanics. At the start of the game, the player finds themselves in a
44
3.3. Included Game Design Elements
hangar waiting behind a huge door to be opened. The possibilities behind this door
should make players curious about how the game will play out. Another example
is when players are presented with different orbs that have the ability to enhance
the gloves players are wearing in the virtual environment. The intention behind
the way they are presented is to make players intrigued about how their choice will
impact the gameplay. Players being able to pick only one of the orbs also adds to
the feeling of curiosity about how the game would play out if they were to pick
another orb.
• Problem Solving: This game design element is only achievable through gameplay
in Astroclimb. In the game, players gain points by interacting with the climbing
holds and as mentioned before the points they gain from climbing holds is inverse
to their size. If the player wants to get a higher score they should seek the smaller
climbing holds and traverse the wall based on their positions. Changing the route
based on this goal represents a problem they can solve by observing the grips and
move on the wall accordingly. The enhancements gained from orbs add another
layer to this problem since the enhancements change the way the player’s gloves
interact with the climbing holds. Additionally, problem-solving directly awakens
critical thinking for players to overcome the problems that are thrown at them.
• Endogenous Value: The most important items players care about in Astroclimb
are their avatar hands and the wall they climb because without them they would
not be able to play the game at all. These objects are also directly related to
succeeding in the game with a high score. Figuring out to which items players
put value in, gives the designer the chance to make the game more compelling by
increasing the value of those items. Improving or changing the most valuable items
to players in Astroclimb is achieved by adding enhancements to the gloves and
changing the climbing hold layout throughout the game.
• Goals: Although it might seem like the sole goal of Astroclimb to reach the end
of the wall, the main goal of the game is giving players a unique experience in VR.
The game’s goal is self-explanatory for players, however, the way Astroclimb is
designed gives players choices about how to enjoy the game. Being present in outer
space alone can be satisfying enough for some players and they can see Astroclimb
just as a sandbox game for having quality time. Players with a competitive mindset
can still try to go for scoring high scores and pay attention to their time score as
well. Experienced climbers can focus less on the aesthetics game provides and just
enjoy the physical activity part of the game. Enabling these different goals for
players also makes the game more inviting to audiences with different backgrounds.
• Fun: It is hard to determine alone whether a game is fun or not. Only the feedback
received during the playtesting can help with assuring the fun aspect of the game.
As mentioned in Section 2.2.1 the definition of the game includes problem-solving,
playfulness, and goals. Including these elements in the game can at least be a
starting point to be able to judge the game as entertaining.
45
3. Conception of Astroclimb
• Unification & Theme: Astroclimb has a clear space theme that is supported by
many visual aesthetics such as the huge spaceship that brings the player to the
climbing spot, the nebula the player is able to gaze upon during the climb, the
black hole positioned below the climbing wall to encourage the player to climb up,
an asteroid belt that occurs at some stage of the game, the spaceships that warp in
and out, the moon colony, and the mechanical interactable objects. All of these
visuals in harmony give the game a unified theme.
• Physical Activity: The fact that Astroclimb includes a physical wall to climb
gives players the opportunity to perform physical training as they play the game.
Since climbing is rather a tiresome activity for players with no or little experience,
it is crucial to balance the game so that players with no experience can enjoy the
game as well. As previously mentioned in Section 3.2, corresponding measures are
taken throughout the design process to balance the height of the virtual wall.
• Challenge: Astroclimb gives three different types of challenges in the game. The
first one is the physical challenge every player has to face to make progress in the
game by climbing up the wall. The second type is hidden in one of the options
presented via orbs that renders some of the climbing holds invisible to the player.
The third type involves beating your own or your friend’s score which also creates
a competitive environment.
• Engagement: Player engagement is the level of continuation desire experienced in-
game, during play, or over a longer period of time when players dedicate themselves
to coming back and playing a game again and again [61]. Astroclimb tries to
achieve this by the scoring system and giving the player a single chance to pick
an orb during the orb selection phase. The scoring system encourages players to
play the game again to beat their or others’ scores. The orb picking system makes
the player curious about the outcome of the game if they were to pick another orb.
Both systems increase the chance of replayability of Astroclimb.
These game design elements are all included in Astroclimb in different areas. Although
the application of these game design elements was successful, there is always room to
improve the game. The next subsection gives ideas about how to improve the current
state of Astroclimb with different design approaches.
3.4 Possibilities for Improvement
The current state of the game was generally satisfying for all the players that tested
the game, however, it is still possible to improve the game. The possible improvements
include gameplay and the positioning of objects in the scenes.
The rotation mechanism of the physical wall has a speed limit which makes pausing the
climb a common occurrence during the game. Although the safety side of this problem
is taken care of as mentioned in Section 3.2, the gameplay still suffers because players
46
3.4. Possibilities for Improvement
with climbing experience are too fast for the counter-rotation speed of the physical wall.
A new game mode could be designed for players with climbing experience that would
prevent them from pausing the climb too often. This game mode could focus on making
the player traverse sideways on the wall so it would give the mechanism enough time to
roll down. Forcing the player to traverse sideways might require some limitations to the
freedom of the player. Providing them with a route to follow would force them to use a
specific set of climbing holds, but in the end, it would be a solution for frequent stalling.
When the player reaches the end of the first part of the virtual climbing wall, a mechanical
owl appears at the left backside of the player. Placing the owl relatively behind the
player caused some problems for players to notice the owl and the interaction of the
player seemed rather uncomfortable while picking an orb. The positioning of the owl
could be optimized which might improve the usability and the overall comfort experience
of the player.
The point and time scores are currently displayed on the gloves of the player at all times,
however, there is no way to keep track of the personal bests or scores of other players.
A global leaderboard could be a good solution for players to check out the overall high
scores when they decide to play the game again. Creating a global leaderboard would
also improve the challenge aspect of the game and act as an amplifier for competition.
Of course, there is always room for improvement and more ideas to make Astroclimb
more appealing to players. This section covered some of the possible improvements that
can be applied to the game. The next main section informs about how the game was
implemented in detail.
47

CHAPTER 4
Implementation of Astroclimb
4.1 Overview
This chapter focuses on how Astroclimb is implemented based on the design concepts
discussed in the previous chapter. First, the planning of different scenes in the game is
explained by pivoting the objects placed that give the outer space and science-fiction
atmosphere to the game. The remaining aesthetics such as audio and further assets
that build and enhance the game’s atmosphere is handled as next. Gameplay is the
following main topic that includes the events players face during the different scenes
in the game. Since the gameplay is immensely affected by the requirements mentioned
in Section 3.1, the section about gameplay also covers its relation to fulfilling these
requirements. The ways how various game design elements are integrated into the game
are the next focal point of this chapter before concluding it with the technical aspects of
the implementation.
4.2 Created Scenes in the Game
4.2.1 The Moon Scene
The game’s starting point is included in the moon scene which gives the player the first
impression of the environment. Other than acknowledging the purpose of the placed
objects in the virtual environment, it is essential to understand the role of this part of
the game, how it affects the player’s experience overall, and how it helps with fulfilling
at least some points of the previously listed design requirements. These aspects should
be investigated for every part of the moon scene in order to see how they are planned to
influence the player.
The moon scene itself can be divided into two different parts: The first part is where
49
4. Implementation of Astroclimb
Figure 4.1: A cross-section of the hangar
- the starting point of the game.
Figure 4.2: The massive spaceship that
brings the player to the climbing wall.
the player finds themselves once they enter the game, the hangar of a spaceship. The
second part is when the player makes out of the spaceship and starts climbing above a
colonized moon. The hangar area is a large compartment (Figure 4.1) at the bottom of
an immense spaceship (Figure 4.2) with some equipment lockers, an oxygen tank, some
crates, and storage places. It also has a huge blast door that opens and allows the player
to leave the spaceship. The objects and the textures chosen for these objects have a
modern look and a sci-fi feeling which can convince players that they are in a spaceship.
This first impression is crucial because it is the first step to make players believe that
they are actually present in a space environment. If they can immerse themselves in this
scene the remainder of the game will make more sense to them although most of the
aesthetics are designed unrealistically. The only disadvantage of this area is that the
whole compartment is not traversable by the player because of the physical limitations of
the VR room setup. The player is only able to move to the left or right in front of the
blast door besides being able to freely observe the whole area.
Once the blast door opens, the player becomes able to access the outer space by stepping
on a hoverboard that is waiting for them in front of the climbing wall. The hoverboard
gives the player time to get ready for the climb as well as observe the scenery surrounding
them. The most noticeable objects in this scene are the moon below the player and the
climbing wall floating in front of the player. The moon’s surface is inspired by the Earth’s
moon and has a white-gray color pattern. The colonization on the moon has living hubs,
transporters, communication satellites, a command base, platforms, and mining vehicles.
All of these objects’ color palette is heavily white-centric. The main purpose of picking a
moon very similar to Earth’s moon, keeping the type and the diversity of used objects
not far from reality, and focusing on white color is to give players something similar
and familiar to what humankind is capable of doing in outer space right now and in
possible near future. This familiarity can help players to get used to the scene faster
by recognizing the functionality of seen objects easily and keep them immersive at all
times. In comparison to these familiar visual aesthetics, the climbing wall stands out as
50
4.2. Created Scenes in the Game
an anomaly in outer space. As previously mentioned in Section 3.2, the climbing wall
is made of a material that is fully transparent, so it does not block a part of the moon
and the spaceships that fly, warp in and out as the player climbs higher. The spaceships
that appear throughout the game have height triggers where once the player reaches
certain heights on the wall they join the game. While the purpose of the climbing wall
is self-explanatory for Astroclimb, the main reason behind the spaceship events is to
keep the game interesting and interrupt the routine climbing activity with some visual
surprises. Once the player reaches a certain height the second main scenery comes in
which is explained in the next subsection.
4.2.2 The Owl Scene
Astroclimb has a single transition point which is handled in the owl scene. Similar to the
moon scene mentioned in the previous subsection, this scene also has a special purpose
in the gameplay and helps further fulfilling some of the design requirements mentioned
in Section 3.1. The remainder of this subsection looks into these points and clarifies the
goals behind applying these points to the game.
The owl scene has two main tasks:
1. Acting as a bridge between the moon scene and the asteroid belt scene.
2. Offering the player a choice which affects the gameplay dramatically.
Once the player reaches a certain height on the climbing wall, they notice that it is not
possible to climb higher in the virtual environment because there is no wall to climb.
However, they see that another part of the climbing wall is bent backward as seen in
Figure 4.4. This certain height triggers the abrupt change of the scene where everything
but the climbing wall disappears and the darkness descends only allowing the player to
see certain objects. One of the goal of this abrupt change in the scene is to catch the
player off guard and surprise them while planting curiosity in their minds about what is
going to happen next. Another goal of this segment is forcing players to pause climbing
for a while as they figure out what is happening. Climbing can be an exhausting activity
for inexperienced climbers, so giving players time to rest their bodies by just hanging up
on the wall should help with reducing the exhaustion the game creates. While the player
is in this state another surprise element joins the game: the mechanical owl designed to
change the game flow.
The mechanical owl (Figure 4.3) is inspired by the owl statue that stands at the top
of the library building of Vienna University of Technology. It appears slightly behind
the climber’s left side and presents three transparent orbs for the player. The player is
supposed to choose one of these orbs by touching them with their avatar hand. The orb
selection triggers the changes to the gloves or to the climbing wall which are explained
in Section 4.3.1. The structure of the designed owl and the chosen texture make it
fit into the sci-fi style of the game perfectly. The idea behind creating this harmony
51
4. Implementation of Astroclimb
Figure 4.3: The mechanical owl de-
signed for Astroclimb.
Figure 4.4: The end of first segment in
the game.
with the design of elements is to help players with making sense of the environment
with current settings. Awakening this feeling in players should directly translate into
improving the immersiveness of the artificial environment for them. Considering the odds
of encountering a mechanical owl in outer space are close to zero, the appearance of the
owl should surprise the player and make them curious about it. Moreover, the changes
applied to the gloves or the wall based on the player’s selection should trigger a feeling of
satisfaction for players since these objects are considered the most valuable to them. The
purpose of these events is to make the game more engaging for players so they want to
continue playing the game with more expectations.
Once the orb selection phase is complete and the corresponding changes are applied, the
owl disappears. This ends the owl scene segment and starts the asteroid belt scene which
is explained in the next subsection.
4.2.3 The Asteroid Belt Scene
Besides the climbing section, the asteroid belt scene also includes the end scene for
Astroclimb. The asteroid belt scene setup has various purposes that satisfy the previously
mentioned requirements further. The primary objectives this scene tries to achieve are
listed below:
1. Completing the scene transition that starts with finishing the first part of the climb
to give players a feeling of switching places in outer space.
2. Creating a more dynamic environment to keep players interested in the game.
3. Finding solutions for the problems that come with VR-related limitations such as
player space and the physical climbing wall’s capabilities.
52
4.2. Created Scenes in the Game
4. Giving players the chance to try out the changes that happened with selecting an
orb.
5. Creating an extra challenge for players by tilting the wall forward.
The remaining of this subsection looks into these objectives and how they are achieved
in the game.
The scene translation is easier in games where the player can move around the environment.
The objects in such environments do not need to be adjusted abruptly. In games like
Astroclimb, the space provided to players to move around is limited. The climbing aspect
of the game adds more to these limitations and keeps the player on the wall at all times.
The physically available space VR setup provides and the motion sickness aspect of VR
take away the ability to dynamically transition scenes in Astroclimb. The designed space
for all Vreeclimber related games is approximately 4 meters by 2.5 meters. Considering
players only move on the wall except for the intro scene in Astroclimb and climbing the
wall is the main mechanic, they do not have too much freedom in terms of movement.
Although the space in the virtual environment is limitless, moving the player around the
outer space with the wall while their body is not moving in the real world would cause
motion sickness as explained in Section 2.2.7. Hence, changing the scene abruptly while
keeping the most important objects, the climbing wall and avatar hands, in place was the
solution to prevent motion sickness and change the scene. The so-far in-game experience
of sci-fi feeling would also give the player the tolerance and acceptance of such unrealistic
occurrences. Once the owl scene is completed, the environment changes back to outer
space, however, this time everything is different in the scene. There is a totally different
color of the nebula that states this new place is somewhere else. The moon colony, the
spaceships, and the floating hoverboard are gone. The major objects in the new scene
consist of a black hole far below the climbing wall, and the asteroid belt which holds the
climbing wall in the middle of it. The asteroids are floating back and forth as the player
climbs up the wall. The main goal of these changes is to give the player a feeling of
suspense and make the game more appealing to them. The increased dynamism during
this part of the game is added to take the player’s attention from climbing occasionally
and gaze upon the scene more often. Another reason behind this is again to slow down
the player’s climbing which would also help with reducing the negative effects of the
physical climbing wall’s limited speed explained in Section 3.4. There are other measures
taken to help with this main issue of players’ climbing speed exceeding the rotation speed
of the physical wall: The changes applied to the avatar hands and the virtual climbing
wall.
When the owl appears halfway through the game, it presents three different orbs which
include small representations of the outcomes of picking them. These are animated
representations that point out these possible outcomes:
1. The first orb renders one of the avatar hands invisible randomly for a couple of
53
4. Implementation of Astroclimb
seconds and it occurs occasionally and repeatedly. This changes the gameplay for
the player in a way that they have to make different decisions for the rest of the
game. If the player does not feel safe by not seeing one of their tracked hands during
the game, they would want to wait until it is visible again to continue climbing.
Another option is guessing the position of the invisible avatar hand and still trying
to hold onto a climbing hold.
2. Choosing the second orb would duplicate the avatar hands and place them a little
far above the avatar hands that are tracked by VIVE trackers. These copies mimic
the rotations and translations of the real avatar hands. Being able to climb with
four hands yields more points since the number of hands touching the climbing
holds is doubled. This option is considered for players that focus on scoring a
high score for the game. Controlling four hands would also be confusing for some
players that can make the climb more challenging. Since the positioning of hands is
more important with four hands, players can aim for the small grips which would
allow them to score even higher scores. The time spent by critically thinking about
choosing specific climbing holds to gain more points should also slow down the
player’s climbing speed.
3. The last orb is rather an alteration applied to the virtual climbing wall than the
avatar hands. Selecting this orb renders some of the climbing holds invisible for
the remainder of the game. This option restricts the number of available climbing
holds for players. This restriction should make the game more challenging and
force players to think about how to position themselves on the wall better for a
smooth climb.
The outcomes of selecting an orb are not the only source for making the game more
challenging and interesting. Tilting the wall forward is another challenge players have to
face in the game.
Once the player reaches a certain height in the game a massive asteroid is launched from
far away in outer space. This asteroid slowly approaches the upper side of the virtual
wall and hits it which results in tilting the wall forwards. All this motion is perfectly
mirrored with the physical climbing wall. The tilting of the wall creates an additional
physical challenge for players towards the end of the game.
Once the climbable part of the wall is over, the black hole below the climbing wall sucks
everything into itself except the player. While the player floats in outer space an alien
spaceship suddenly warps in which indicates the end of the game. The ending of the
game should leave the player with mixed feelings. The appearance of an alien spaceship
might worry or excite players about what is going to happen to them. They might as
well be disappointed in the massive spaceship that brought them to the celestial climbing
wall and did not come back for them. If the game can rise such feelings in players, it
means that the game was an immersive experience for them.
54
4.3. Gameplay and Atmosphere in the Game
This subsection explained the main scenes in Astroclimb while trying to not go into
details about the gameplay. The next subsection gives more information about how the
gameplay is structured and how the atmosphere in the game is created.
4.3 Gameplay and Atmosphere in the Game
4.3.1 Game Chapters and Events
The previous subsection already informs about the game flow by mentioning the environ-
mental design of the three main scenes. The game, however, should be divided into parts
differently which includes parts from different scenes. Each of these chapters includes
various events that possess distinct influences on the game flow and game gameplay. It is
crucial to understand the reasoning behind these events in every single chapter and how
they can affect players.
Astroclimb mainly consists of three chapters which can be called the intro part, the
climbing part, and the outro part. The intro part starts with the game and ends once the
player touches the first climbing hold on the wall. Since this segment is fairly short, there
are only a few events happening in this part: Once the player is out of the spaceship
and on the hoverboard, the massive spaceship ascends slowly and then warps out after
reaching a certain speed. This event leaves the player alone with the climbing wall, and
the hoverboard they are standing on. The departure of the spaceship also unlocks a lot
more space to look at that gives the player the perfect time to look around and see what
this outer space offers. Besides starting the game, the first interaction with a climbing
hold also triggers the hoverboard to leave and make it glide around the climbing wall as
the player climbs up. The events happening in the intro chapter are pure aesthetics to
make the environment compelling for the player. The following climbing chapter includes
similar events that improve visual aesthetics as well as events that impact the gameplay.
Once the player starts climbing, various events occur until the end chapter of the game.
The first events consist of spaceships warping in and out, and having pursuits on each
other. The goal behind these purely visual aesthetics-related events is to prevent the
game from becoming dull and make players take a moment by giving them something
to observe as they climb. As previously mentioned in Section 4.2, the orb selection
phase that comes with the mechanical owl forms the important event that impacts the
gameplay. Building upon the already existed mechanics, being able to touch the climbing
holds with avatar hands and gain points in this case, should give players a feeling of
progression and something to look forward to for other possibilities. The main purpose of
changing and improving the way players can gain points, and the different distribution of
climbing holds on the wall is to keep the gameplay and game flow dynamic. Keeping the
dynamism in the game should force players to react to changes and adapt accordingly.
As players try to adapt to the changes after the owl’s visit, the next important event
is the crashing of an enormous asteroid to the climbing wall. If the player pays enough
attention, it is possible to see this asteroid slowly making its way to the upper side of
55
4. Implementation of Astroclimb
the wall. Noticing this before the crash would make the player nervous and maybe stop
climbing for a moment thinking that it might hit them. When the crash happens, the
event changes the game flow as well as some visuals in the environment. On the one
hand, as mentioned in Section 4.2, the tilting of the wall challenges players physically.
On the other hand, the crash destroys a part of the upper wall which causes many wall
fragments to spread into outer space. Since climbing a tilted wall can be very challenging
for some players, this event is put towards the end of the game.
The last event occurs at the end of the game as the black hole sucks everything but the
player in and an alien spaceship arrives. Taking away the climbing wall from the player
should signal the player the end of the climb and therefore the end of the game.
The next subsection goes more into detail about gameplay and explains how scoring
works and changes throughout the game, and what other information such as a timer
and a height indicator is there for players.
4.3.2 Score, Timer, and Height Indicators
Astroclimb possesses various indicators attached to the lower side of the avatar hand
models as seen in Figure 4.5. These indicators help with creating the gameplay for
Astroclimb and induce distinct game design elements into the game. This subsection
informs about how these indicators work and how they contribute to the requirements
explained in Section 3.1. Scoring in Astroclimb is achieved by interacting with climbing
Figure 4.5: Time and height indicators are placed on the left avatar hand, while the score
is on the right avatar hand.
holds. These climbing holds are worth 10 points if their size is considered large, 20 if
they are small. If the player already touched a climbing hold, its color changes to green
indicating that this climbing hold is marked, and touching it again will not issue any
additional points. In order to prevent players interact with many climbing holds in quick
successions to abuse the pointing system, the following measure is taken: The player has
to stay in contact with the climbing grip for at least 1,5 seconds and the points apply
56
4.3. Gameplay and Atmosphere in the Game
once that climbing hold’s color turns into green. This sums up the basics for the scoring
system, however, the scoring changes for most cases as following once the player selects
an orb:
1. If the orb that duplicates the avatar hands is chosen the scoring system stays the
same, however, the copies of avatar hands are also able to score points if they come
in contact with climbing holds.
2. If the orb that makes one of the avatar hands randomly invisible is chosen, the
scoring system rewards the player by doubling the point gain for each climbing
hold that is touched by an invisible avatar hand.
3. If the orb that renders some of the climbing holds invisible is chosen, the point gain
for every single climbing hold is doubled.
The alterations made in the scoring system after selecting an orb are to balance the
game in terms of scoring as fairly as possible. The orb choice for players that focus on
scoring high scores would be the third orb explained above since that choice doubles the
point gain in all cases. Instead of scoring high points, if players focus on completing
the game as quickly as possible to get a good time score, the game provides a timer
for elapsed climbing time. The timer starts as the player touches a climbing hold and
ends once the player reaches the very end of the climbing wall. Players that focus on
achieving a short climbing time would benefit more by picking the first orb option listed
above. Occasionally not being able to see the avatar hands and a climbing wall with
missing climbing holds might cause players to stall and think about their next steps
longer than usual. Besides providing challenging and competitive gameplay, the timer
and the score indicators also aim to reach players with different preferences to create a
diverse gameplayer base.
Unlike score and timer indicators, the height indicator is added only to give interesting
statistics to players. The number on this indicator change as the player climbs higher on
the wall. This piece of information is available to the player at all times just by looking
at their left avatar hand.
The next subsection switches from gameplay and mechanics to building the visual
aesthetics that create the sci-fi atmosphere in the game.
4.3.3 Modeling and Use of Game-ready Assets
Astroclimb uses a mixture of many self-modeled and game-ready assets that create an
outer space atmosphere with sci-fi elements in it. These elements directly improve the
visual aesthetics of the game. The remainder of this subsection informs about the objects
and areas designed for the artificial space scene and where the inspiration comes from for
using these specific objects.
57
4. Implementation of Astroclimb
Figure 4.6: An early design stage of
the mechanical owl in Blender.
Figure 4.7: The hoverboard designed for players
to stand up on before the climb.
One of the initial steps to create this outer space was building the skybox for the
environment in Unity. For the first part of the climbing, a nebula with light colors that
include green and blue is chosen to give players a feeling of relaxation. In contrast to this
choice for the asteroid belt scene, a red-heavy nebula was chosen to signal the danger of
the objects in the scenery. One of the first objects specifically designed for the scene was
the hoverboard seen in Figure 4.7. Blender [15] is used for modeling this object which is
then textured with Vreeclimber’s logo and colored with matching colors to the nebula’s
blue & green. The idea of using a hoverboard is inspired by the movie series Back to the
Future [65].
The mechanical owl is another object designed specifically for the game by using Blender
again. Figure 4.6 shows an early mesh version of it in Blender. The textures are provided
by free online resources. Shiny textures are used for the owl to make it stand out in the
dark.
The moon colony (Figure 4.8) is one of the largest objects in the game, consisting of
many self-designed and modeled objects and game-ready 3D assets provided by NASA
[111]. The terrain of the moon is made by Unity’s official terrain tool to create an
area for the colony. This colony area includes living hubs for astronauts, debris that
shows unsuccessful attempts of the folk on the moon, structures they build such as giant
communication satellites, a command center, spaceship launcher platforms, and mining
equipment. These objects are placed in a manner so that they can give the impression of
a colony to the player.
The spaceships (Figure 4.10) used in Astroclimb are free assets, including destroyers and
TIE fighters from Star Wars series [67], and Vipers from the Battlestar Galactica [64]
TV show. The goal behind using known spaceships from successful TV shows and movie
58
4.3. Gameplay and Atmosphere in the Game
Figure 4.8: The moon scene. Figure 4.9: The asteroid belt scene.
Figure 4.10: From left to right: The destroyer, Viper, TIE fighter.
series is to create a surprise effect for players when they see them in the game.
The asteroids in the asteroid belt scene (Figure 4.9) are taken from Unity’s asset store
and stored as prefabs in Unity. The algorithm that creates the asteroid belt picks one of
these prefabs randomly, adds a random velocity and tumble rotation to it, and sends
it through the outer space towards the climbing wall. Dozens of these asteroids are
launched at the same time which creates the asteroid belt. The other mention-worthy
object in the asteroid belt scene is the black hole (Figure 4.9) which is created by using
the particle system in Unity. The purpose of placing the black hole below the climbing
wall is to encourage players to climb higher up.
The use of these objects created satisfactory outer space scenes that fit the concept of
Astroclimb. Besides visual aesthetics, background music and sound effects also improved
the aesthetics of the game which are explained in the next subsection.
4.3.4 Music and Sound Effects
One of the most influential aesthetics types that improve immersion overall is audio.
Astroclimb provides this kind of aesthetics in different ways such as playing music in
the background at all times and supporting events with sound effects. This subsection
59
4. Implementation of Astroclimb
investigates the reasoning behind choosing multiple background music tracks and playing
sound effects in certain situations.
Background music is the most noticeable auditory aesthetic of Astroclimb that changes
overtime during the game. As previously mentioned in Section 4.3.1, the game is divided
into three main chapters that reflect the game states the player can be in. For the intro
part, a country-western song called Benson Arizona [185] performed by John Yager is
picked. The song’s relaxing tunes were considered an adequate fit to get the player ready
for the climb. It is also one of the soundtracks from the movie Dark Star [66] which is an
old American science fiction comedy in which the story involves funny events in outer
space. The next background music that follows Benson Arizona is Echoes [186] by Pink
Floyd. This song is purely instrumental at most parts and has a fairly slow pace at the
start. Since Astroclimb only uses the first three minutes of this track at most, this makes
the song a fine fit for the longest part of the game. The idea behind picking this song was
to keep the player focused on the climbing and the events that occur at certain stages of
the game. In comparison to Echoes, Mr. Spaceman [187] by The Byrds, which is used for
the outro scene, is a fast-paced song with the genre of country-rock. It was planned that
this dramatic change of tunes would create a wake-up effect on the player and signals the
end of the game. Science fiction and space are the common themes in these songs. The
use of Benson Arizona in a science fiction movie, Echoes evoking an outer space feeling
with its melody, and Mr. Spaceman including lyrics that describe aliens create their own
relationships to these themes. Besides these background music tracks, the owl phase
also has a special background sound which can be described as static noises. The goal
behind this change is to give the player a feeling of being somewhere unexpected such as
in-between dimensions. Jiulin Zhang et al. also point out the importance of background
music in video games for increasing immersion [41], however, it is not the only source for
auditory aesthetics. Sound effects are another source that complements them to increase
the immersion level in the game.
Since Astroclimb takes place in outer space, logically it does not make sense if someone
hears noises or sound effects in such a scenario, however, excluding sound effects from a
digital game would cause a less immersive experience [135]. In Astroclimb, sound effects
are assigned to important events that happen throughout the game. Here is a list of
some of these events that are supported with auditory feedback:
• When the hangar door opens at the start of the game
• When the massive spaceship that brings the player to the climbing location in the
game leaves
• When spaceships warp in and out
• When the player scores points by using a climbing hold
• When an orb is selected and the changes are applied in the scene
60
4.4. Technical Aspects
• When the second part of the wall straightens up after the owl phase
• When the large asteroid hits the wall and a part of the wall breaks into pieces
With the addition of the background music tracks and various sound effects, Astroclimb
aimed to improve the immersion level of the game and provide a better experience to
players. This subsection finalizes the conception of the game in terms of gameplay and
game atmosphere. The technical aspects of the game such as the implemented core
scripts and how these scripts ensure the gameplay are explained in the next subsection.
4.4 Technical Aspects
4.4.1 Calibration Process
Astroclimb’s core template consists of scripts that enable the climbing logic in the game.
These scripts are responsible for calibrating the scene by aligning the physical objects
with their virtual representations and keeping them aligned at all times throughout the
game. There are two distinct calibration processes that make climbing in the virtual
environment possible:
1. Calibration of avatar hands and feet
2. Calibration of the climbing wall
Calibration of the avatar hands and feet starts with finding the correct VIVE Trackers in
the environment with the help of TrackerIdentifier.cs script. Then, AvatarCalibration.cs
orients the hand and feet avatars towards the wall plane. In order to achieve this, the
hand and feet avatars are rotated around all three axes until the avatars’ wall-facing and
ground-facing planes are oriented towards the predefined wall and ground plane in the
game. With the help of these scripts, players are able to use their hands in the virtual
environment to interact with objects without suffering from any nonalignment issues.
This calibration process is crucial due to the fact that it enables players to use their
hands accordingly without breaking the immersion. Besides hand and feet calibration,
climbing in Astroclimb also requires a perfect alignment of the physical wall.
The wall calibration process consists of two parts: The initial calibration and the ongoing
calibration during the game. The initial calibration process is accomplished mainly by
the SceneCalibrator.cs script. First, the script tries to find a wall tracker on the right
side of the wall and another one on the left side. Once these two trackers are found, the
program needs to figure out which pair of trackers are found, as there are four possible
combinations of wall trackers. Therefore, the vertical distance between both trackers as
well as their horizontal positions is used for the identification. After the identification,
the VR environment is shifted along the x- and z-axis depending on the position of
the identified tracker and its corresponding position on the virtual board. Then, the
climbing holds are shifted along the y-axis depending on the vertical difference between
the tracker and the predefined position of the tracker on the virtual wall. This series
61
4. Implementation of Astroclimb
of processes take place at the beginning of the game, however, in order to keep the
climbing holds aligned, additional measures have to be taken due to the rotation of the
physical wall. CorrectVerticalError.cs and CameraShift.cs are responsible for this task.
CameraShift.cs moves the VR environment upwards while the physical wall is rotating.
It also adjusts the speed of this movement whenever the speed of the physical wall’s
rotation is changed. The upward movement is implemented by increasing the velocity
of the VR environment’s Rigidbody in its local y-Direction. CorrectVerticalError.cs has
hardcoded upward movement speeds for the VR environment. Although these speeds are
very close to the physical wall’s rotation speeds of different levels, they do not exactly
match the actual speed of the physical wall’s rotation. Therefore, in time a vertical offset
between the hands & feet and the climbing holds appears. This script is responsible for
compensating for this loss in accuracy.
Although the virtual environment is slowly shifting upwards in the game, this slow but
steady shifting is not noticed by any testers due to their focus being on somewhere else at
all times. With the combination of these calibration processes, the climbing experience
does not break immersion in Astroclimb. Besides climbing-oriented scripts, there are, of
course, scripts that enable the gameplay. The next subsection explains some of these
scripts.
4.4.2 Scripts
The scripts used to manage the logic in the game can be divided into two different
types: The scripts that are tightly coupled to each other and react to game state changes
handled in other scripts, and scripts that are mostly independent of the events happening
throughout the game.
Scripts such as GameplayController.cs that is responsible for dictating the game’s current
state, MusicController.cs which changes the music playing in the background based on
the game’s state, MilestoneController.cs that sets the second stage during the climbing
part of the game by changing the environment and enabling the second part of the
climbing wall are dependent to each other. The triggers that change these game states
are based on the player’s players movements and position. As an example, touching
a climbing hold changes the game state from intro to climbing. Since the game is a
sequence of events and each small change that is supposed to happen, has triggers,
the order of the events is regulated by using one of Unity’s scripting concepts called
Coroutines [171] and supported by boolean values to control their repetitiveness. Other
than scripts that control the general flow of the game, there are also multiple scripts
that are responsible for dictating the outcomes of certain events. These scripts work in
harmony to be able to create the desired logic. OwlController.cs, ManipulateFirstOrb.cs,
ManipulateSecondOrb.cs, and ManipulateThirdOrb.cs together handle the owl’s and
its orbs’ animations once the player reaches a certain height on the climbing wall. In
addition to these scripts, ChoiceManipulator.cs prepares the events dependent on the
chosen orb which includes making changes to the avatar hands and the wall’s climbing
62
4.4. Technical Aspects
holds. WarningController.cs is another highly-dependent script that needs to know the
current height of the player on the wall all the time so it can display a warning text to
the player stating that the player should pause climbing if the player gets too close to
the upper side of the physical wall. These scripts are some of the core building blocks for
the logic of the game, however, the game also consists of some semi-independent scripts.
The semi-independent scripts only get informed about the state of the game once and
handle the logic accordingly. BlinkBlink.cs that is responsible for making certain light
sources of the massive spaceship blink, and Asteroidshower.cs that spawns different types
of asteroids towards the wall’s direction are good examples for this type of script. The
combination of these scripts and the core ones create the game logic that creates an
essential part of the Astroclimb experience.
63

CHAPTER 5
Evaluation
This section covers the evaluation of the previously described implementation. It starts
with going into details about how the setup is done to create an appropriate testbed for
the evaluation. The Covid-19 measures forms the second part as they were crucial to
enable the evaluation and testing in the first place. Then the way how the testing is
handled composes the next subsection. Finally, the results are evaluated and discussed
further. The evaluation methods include answering questionnaires, one before and one
after the test session, observation, and an optional short unstructured interview after the
test.
5.1 Setup
As mentioned before in Section 1.2, the implementation was built upon the Vreeclimber
project. The wall is 4.6m high that consists of a combination of 28 wide block rows which
hold a total of 238 climbing grips and 4 VIVE Trackers. As seen in Figure 5.1 of a row
block, each row contains 8 or 9 climbing holds. The arrangement of these climbing holds
on the wall is done in a way that the whole mapping of grips can resemble a bouldering
experience. The wall can roll downwards with a maximum speed of 4.78m/min which can
simulate endless climbing. Furthermore, the wall can tilt up to 20° to create the feeling
of an overhanging cliff. The whole system does not produce noise beyond 68 decibels
in good condition1. During the evaluation, all described features of this rotating wall
played a central role in the outcome.
Additionally, strict safety measures were taken. The participants had to wear a suit with
safety ropes attached to it. As seen in Figure 5.2, an operator had the duty of holding the
climber’s ropes to prevent unwanted accidents. The sports mat on the floor is a further
1The inner parts of the wall need to be oiled regularly to keep the noise at desired levels.
65
5. Evaluation
Figure 5.1: The Vreeclimber wall.
measure to prevent or reduce the effect of possible injuries in case of a participant’s fall.
Participants also had to wear climbing shoes that are designed for bouldering.
Because of the worn HTC VIVE Headset during the climb, various adjustments had to
be made to the safety ropes without compromising safety. In a regular climbing scenario,
a safety suite has carabiners to attach the safety rope to which then goes up at the
front of the climber (Figure 5.2). If the same concept was kept for climbing in VR, the
front ropes would interfere with the VR headset. That would be undesired because of
safety, immersion, and tracking reasons. To prevent this from happening a robust bar is
attached between the two ropes coming from the front side of the carabiners. (Figure
5.4) These adjustments kept the ropes from touching the VR headset.
As mentioned before in Section 3.1, the success rate of tracking has a direct and immense
effect on immersion. Placing the VR equipment based on needs was another important
part of the setup. 4 lighthouses and 8 VIVE Trackers are used for this matter to minimize
any possible tracking issues. The lighthouses are used to track the position of the headset,
controllers, and trackers inside the Chaperon area [155]. For the best possible tracking
experience, VIVE Trackers and the VR headset should be visible to multiple lighthouses
simultaneously. To enable this scenario, 2 of the VIVE Trackers are placed on the dorsal
side of hands, and 2 on the dorsal side of feet. Although these placements of VIVE
Trackers are on point in terms of tracking limbs accordingly, the tracking of these VIVE
Trackers becomes difficult if the lighthouses are placed improperly. Figures 5.5 and 5.6
show possible positions of the VIVE Trackers on the limbs during the climb. In these
cases, the VIVE Trackers find themselves in-between two solid objects, hands/feet, and
66
5.1. Setup
Figure 5.2: Operator holding the
climber.
Figure 5.3: Carabiners with the
safety ropes.
the wall. To always keep these trackers trackable, various room setups with different
positioning of lighthouses are tested. After comparing the results of these tests, two of
the lighthouses are placed at the low and middle levels of the wall and close to the wall.
The other 2 lighthouses are positioned far back from the climbing wall at upper levels
which are mainly responsible for tracking the 4 trackers on the wall. These placements
also got approved by Prof. Kaufmann who specializes in the Augmented and Virtual
Reality research area.
Figure 5.4: Extra safety measures with ropes and a robust bar.
There are two reasons behind using 4 VIVE Trackers for the climbing wall:
Calibration process: The application starts with a calibration process where two
VIVE Trackers must be present on the front side of the wall simultaneously. With the
help of the calibration process, the physical climbing holds on the wall align with their
virtual representations in the application.
67
5. Evaluation
Figure 5.5: Tracker is hidden be-
tween the body and the wall.
Figure 5.6: Tracker is hidden be-
tween the hand and the wall.
Ongoing aligning process: As the wall rotates, the climbing holds stay aligned with
the help of an algorithm that needs at least a VIVE Tracker getting tracked in the
Chaperon area.
Because of the number of grip blocks, the use of at least 4 VIVE Trackers on the climbing
wall is required to be able to achieve these goals. Besides the overall aligning processes,
further in-game measures are taken in order to keep the climber safe and the tracking as
smooth as possible, and increase the feeling of immersion:
In-game tracker covers: As tracker covers, spheres with dangerously looking electrical
circuits are placed where the VIVE Trackers on the physical wall are supposed to be.
The pure purpose of making these virtual representations look alarming is to discourage
the climber from touching or holding onto the VIVE Trackers because applying force
on this fragile equipment or covering these trackers at any point during the runtime of
the application may result in reducing the quality of tracking and as well as the level of
immersion drastically.
Warning text: The climber is kept at a so-called climbing window during the climb
which means that the climber is restricted to not climb too high up on the physical wall
because of safety reasons. Exceeding this high threshold results in giving the climber
visual feedback with a warning sound to make them pause climbing for a little bit.
Skipping to end: It is possible for the climber to not want to continue with the
content or with the climb itself because of various reasons. For that matter, a UI button
is added to the game that is only available for the operator present at the PC. Pressing
this button will finish the simulation and jump to the end screen of the game.
68
5.2. Covid-19 measures
Shoe and glove size: 3 different virtual gloves and shoe sizes are available for the
climber to pick from at the start of the game so their real hand and shoe sizes can match
with the virtual representations as closely as possible.
All the points mentioned above created the setup for a safe and immersive experience.
5.2 Covid-19 measures
Since the testing requires the use of the rotating wall, operators and participants had to
be present at the workshop. A Covid-19 procedure is prepared to minimize the risk of
infection during the time spent in the workshop. Below is the list of taken measures:
• Participants and operators must be tested for Covid-19 and the results must be
negative.
• A maximum of 4 people can be present in the workshop at the same time.
• Participants and operators must wear FFP2-masks to be able to enter the workshop.
Since the test sessions will take place inside of TU Wien campus, all campus rules
apply during entering and leaving the building. A full list of additional measures
can be read on the official pages [182].
• Participants must keep their FFP2-masks during the climb.
• Participants must use the provided hand sanitizers before and after the climb and
the test session.
• The provided climbing shoes must get disinfected after use.
• The VR equipment must get disinfected before each climb by the operators. Op-
erators will wear plastic gloves during the sanitization process and a new pair of
gloves will be used between each climb.
All the measures listed above were followed strictly.
5.3 Testing
The current situation the world is in because of the Covid-19 pandemic and the require-
ment of being present in the workshop to be able to participate in the study caused
a low participation rate than expected. Furthermore, it also affected the diversity of
the participants in a negative way. All participants were males, but they had a diverse
climbing, VR, and gaming experience, and age spectrum. For detailed background
information about the participants, the following table is provided.
69
5. Evaluation
Age Sex VR Experience Climbing Gaming hours Gaming hours
Experience per week for VR per week
22 male 3 2 3-6 1
27 male 5 2 3-6 0
32 male 4 3 0 0
47 male 3 5 1-3 <1
31 male 2 3 3-6 0
Table 5.1: Background information about participants
The test begins with following the Covid-19 measures. After filling the pre-questionnaire,
the participant gets ready for the game by wearing the necessary equipment and listening
to the briefing. Once the calibration for the wall, hands, and feet is done, the participant
is ready to play the game. After the game, the participant removes the VR equipment, fills
out the after-questionnaire, and has a small interview with the tester. For a more detailed
step-by-step walkthrough of this procedure please read Step-by-step Test Procedure in
the appendix.
Approximately 30-40 minutes got reserved for each session and the planned time was
enough for every test person. The test sessions went mostly smooth in terms of timing
apart from the first participant. There were some technical problems regarding the wall
calibration process, but the issue got resolved in a short time.
Besides this small delay, there were a couple of further problems with the comfort of
some of the climbers. The assembled hand-straps that were designed for holding the
VIVE Trackers on the hands got uncomfortable towards the end of the climbing. One of
the test persons also reported that there was a slight offset between their left hand and
its virtual representation which made reaching the grips not as precise as planned.
5.4 Results
The questionnaires answered by the participants created a mix of qualitative and quan-
titative data. Since most of the questions that grade different aspects of the game are
followed up by personal comments, the answers to most of the questions will be handled
separately and include citations from the participants about their thoughts towards their
experience. Figure 5.7 shows the effect of various elements used in the game to increase
the immersion levels.
5.4.1 Immersion, Aesthetics, and Story
Aesthetics are one of the core game design elements that have the most direct relationship
to a player’s experience. They must make sense to players so they can relate events
and objects to the environment they find themselves in. If these elements seem logical
70
5.4. Results
Figure 5.7: Effects of different game design elements on immersion.
to them for the environment, players can immerse themselves easily. Figure 5.7 states
that the use of aesthetics was successful (See Section 5.4 for evaluation results), and this
game design aspect was well applied. The design of the environment helped the players a
great deal with immersing themselves and feel like a part of the environment. One of the
participants mentioned in his comments: “In the beginning, the door and the interior of
the space station were realistically designed. This gave me a strong feeling of immersion
right away.” Another participant mentioned that the launching of the spaceship, the
surroundings in general, the background music, and the transition from the spaceship
to the wall were particularly immersing. Sound effects are also counted as a part of
aesthetics. Maybe not as successful as the objects included in the environment but the
sound effects aided to enhance immersion.
In comparison to environmental elements and sound effects, the story had a lesser impact
to increase the immersion, however, as the graph states, it still contributed to giving a
more immersive experience. The story was a prelude to the main event in the game and
tried to set the stage for the player before experiencing the VR environment. Feeling
immersed with both of these game design aspects also means that the connection between
aesthetics and story was successful. The story shortly states that the player is in a space
odyssey and makes a pit-stop to climb an anomaly wall. This small piece of information
gives the player what kind of environment to expect once he wears the VR glasses. The
starting point which is the hanger of an enormous spaceship confirms the story for the
player and then seeing the climbing wall for the first time supports this story further.
These elements should complement each other to make players feel more immersed in
the scene.
71
5. Evaluation
The existence of a non-playable but interactable character in the game gave controver-
sial feelings regarding adding more immersion to the experience. Almost half of the
participants stated that the owl did not help with increasing immersion levels at all
while the other half felt the effects of it to a great extent. One of the participants that
did not find the owl immersive reported that it was lacking realism because an owl is
unnatural both in climbing and space. Another one acknowledged that he recognized
the owl late because it was kind of behind him and pointed out that a climber almost
always looks towards the wall instead of checking the front view. The high experience of
these participants in climbing and their low to none gaming habits can be the reasons
behind their interpretations. It is possible that the expectations from a game can differ
on an individual level. However, none of these participants reported that the existence of
the owl was immersion breaking. This result can be explained with Cheng and Cairns
study [22]. They examine in their study how a game should behave and what would
happen if that behaviour was deliberately made to be incoherent. The results suggest
that immersion within an application can overcome effects that are completely against
user expectations. Other participants reported that the interaction with the owl was
greatly immersive and one of the most memorable events throughout the game.
The occasionally appearing vertical offset between the hands and the virtual gloves,
the need for rearranging of headphones during the climb, the wait to continue climbing
because of the previously mentioned safety reasons were reported as immersion-breaking
parts during the climb.
5.4.2 Fun, Tiredness, and Motion Sickness
Fun is one of the most iconic game design elements a game needs to possess. Figure
5.8 shows how engaging the participants find the game. It affirms that all participants
enjoyed their experience greatly. However, this is just a general statement from the
participants which does not inform the game designer about the specifics of the parts
that made the game enjoyable, hence the participants were also asked about why they
find the game engaging. One of the participants reported that the game was unique
while another one found the general idea and the design behind the game neat. Another
participant found the idea of being able to climb infinitely appealing. The combination
of physical climbing with a space-themed VR environment that offers different levels and
being able to explore the environment to an extent were the aspects for a participant
that made the game fun.
As explained previously in Section 4.3.1, the player is given a choice through the middle of
the game which affects the rest of the climb remarkably. As seen in Figure 5.9, participants
found that change in the flow of the game (more) challenging or/and engaging. One
participant reported that he misinterpreted the goal.
Furthermore, most of the participants reported that they would not be interested in
playing a similar game on a PC. One of the participants believes that physical climbing
72
5.4. Results
Figure 5.8: Effectiveness of some of the in-game experiences.
Figure 5.9: Effects of the chosen orb on the game experience.
is essential in such a setup and the controls on a PC game would make the game boring.
Another participant thinks that experiencing such an environment in VR is the most
interesting aspect of it and the way you can immerse yourself when physical activity is
at present is unique. These comments indicate that it is more desirable and makes more
sense to participants to play a game that involves physical activity in a VR environment.
73
5. Evaluation
A mention-worthy find is that the participants described the game as relatively tiring
as seen in Figure 5.8. This was mentioned multiple times during the short interviews
after the climbs as well. When the specific part asked about the tiring part of the climb,
participants pointed out the time towards the end. Towards the end of the climb, an
asteroid crashes the top side of the wall which triggers the physical wall to tilt forward.
This means that the participants climbed at least a quarter of the wall while it was tilted
which required more force to hold onto climbing holds. Considering no one quit climbing
during the test, this tells that the enjoyment the players received took over the tiredness.
Figure 5.8 shows that there were not any motion sickness complaints from the participants
during or after the game which is a good sign. This piece of information indicates that the
decisions made while designing the game helped with preventing possible motion sickness
cases. This can also be explained that all of the participants had VR experience before
and are used to the situation. As Alex Riviere mentions in his blog [133], some game
developers intend to say that with experience of hours playing in VR, people eventually
get used to it, and the problem of motion sickness will be resolved on its own with time.
5.4.3 Problem Solving, Critical Thinking, and Replayability
As previously explained in Section 4.3.1, the player has to make a choice between three
presented orbs to be able to continue climbing. Although the orbs are animated and
each of them gives hints about how the gloves get enchanted, the situation was still not
perfectly clear to the player. The purpose of this section of the game is to force players to
think critically and guess the changes that will be applied once the climb continues. On
one hand, as seen in Figure 5.10, the participants found the idea of these enchantments
fairly interesting. On the other hand, figuring out the changes that will be applied for the
rest of the game was fairly difficult. Two of the participants reported that they did not
think about the outcome and randomly chose one of the orbs. One of the participants
stated that he chose the middle orb because he was sure what was going to happen if
that orb would be chosen. Another participant figured out the possible outcomes of every
choice and chose the one that seemed the most challenging amongst them. Moreover, a
participant addressed that one of the animations was misleading because no one would
expect the gloves to get duplicated. Another participant reported that he misinterpreted
the same animation and thought picking that orb would specify which grips to hold as
next.
Making participants misinterpret things in the game can be seen as a design issue,
however, misinterpretations build the path to solve puzzles. The main goal is actually
achieved here by making some of the participants guess things wrong.
Although the choices were generally unclear and relatively hard to understand all par-
ticipants managed to understand that they had to pick an orb to be able to continue
climbing. This behaviour states that they were able to solve the problem that was thrown
at them.
74
5.4. Results
Figure 5.10: Participants’ thoughts on orbs.
After the climbing session ended for one of the participants, he was curious about what
would happen if he picked one of the two other orbs. Explaining the outcomes made him
interested enough to play the game again and this time he picked another orb once that
stage is reached in the game. He reported after his second climb that he enjoyed how
differently picking another orb affected the outcome of the climb. This behaviour shows
curiosity leads to the replayability of the game which is another important game design
element. Figure 5.11 shows how likely it is for the participants to play again to see the
other presented options would affect their experiences. Besides curiosity, there are other
aspects such as challenging other players that can lead players to replay the game. All
participants agree with this statement and as seen in Figure 5.11, everyone is eager to
play the game again to beat their own or another player’s score or time.
5.4.4 Element of Surprise, Curiosity, and Progression
One way to keep players interested in the game they are playing is by creating surprises
and unexpected events. All participants experienced at least a moment where they were
surprised. Three of the participants found the appearance of the owl and the options
it presents surprising. Another participant reported that the asteroid hitting the wall
which makes a part of the glass wall shatter caught him off guard. The hangar door’s
opening and seeing the space environment for the first time was surprising for another
participant. One of the participants reported further that noticing how high he climbed
after looking down surprised him.
After the climb, the participants were also asked whether they felt the physical wall
getting tilted at one point during the game. Most of the participants were baffled by
75
5. Evaluation
Figure 5.11: Likeliness to play the game again.
the question because none of them noticed that the wall they were attached to actually
tilted forward. Another important acknowledgment was that none of them felt the wall
was rotating although they knew that is how the wall operates. These observations can
be explained by how highly immersed the participants were in the game.
Curiosity is another way to make a game appealing. A participant reported that the
very beginning of the game where he waited for the door to open made him curious
about what is behind the door. Another source of curiosity was the owl and the possible
outcomes of picking an orb which made two of the participants curious.
The UFO ship that arrives on top of the climber at the end was another element of the
game that triggered curiosity for one of the participants. He stated that he expected the
enormous spaceship to come back and pick him up. The arrival of the UFO left him with
questions in the end. Although the game ends at that point, it still gives the players
things to think about even after the game.
One of the participants reported that none of the aspects in the game awakened curiosity
in him because he was too focused on climbing.
The pause created during the game where the player has to make a choice to continue
climbing gave all of the participants except one a sense of progression. Giving players
a milestone to reach makes them curious about what is to unfold next and creates
expectations. These aspects prevent the game from becoming stale. The participants
are further questioned about the motivation level reaching a milestone gives to progress
further. As seen in Figure 5.12, all participants except one felt relatively motivated to
76
5.4. Results
continue with the game after the interaction with the owl.
Figure 5.12: Motivation level to continue climbing after the milestone.
5.4.5 Overall Results of Applying Game Design Element
The purpose of the data collected from the participant was to find out how likely it is
to apply generally accepted game design practices and methods to the virtual reality
platform. The core game design elements aesthetics, story, mechanics, and technology
are all present in Astroclimb and they complement each other. Although the use of these
elements can get transitioned to virtual reality platforms successfully, there are other
core concepts such as immersion, usability and game feel that need to be looked into
because they mean differently for VR games.
Immersion is the most important aspect of virtual reality. Every other element used
in a game should try to add to the overall immersion level to increase the satisfaction
rate of players. The importance of immersion increases further if the physical play area
needs to be in harmony with the world created in the virtual reality environment. In
this case, the alignment of the physical wall, the climbing holds on them, the virtual
gloves and shoes should match positioning-wise as perfectly as possible with their virtual
representations, otherwise playing this game would not be possible at all. This is done
by the calibration processes at the start of the application and the (almost) perfect
alignment carried on throughout the game. If other physical objects are involved in
the game design besides the VR equipment, further measures have to be taken to keep
the immersion at a high level. Besides the calibration process and providing a core
concept of being able to climb in a virtual environment, in-game elements should make
77
5. Evaluation
players immersed in the scenario. The data gathered from the climbing sessions that are
discussed in this section previously clearly states that the participants were immersed in
the game. Creating the environment for players in virtual reality should take “presence”
into account. Presence also called “telepresence” is a phenomenon that makes people be
able to become connected with a world outside of their bodies with the help of technology.
Since players become physically a part of the game they are playing, the experience with
VR glasses produces a visceral feeling of being in a simulated environment. Creating this
simulated environment successfully adds more to the immersion levels of the game.
Usability refers to maximizing the effectiveness and efficiency of the game elements
used in a game while keeping the players satisfied. It is about delivering an enjoyable
experience while keeping away the unnecessary interruptions or challenges that have not
been designed by the developers [85]. As mentioned before, Astroclimb is built upon
Vreeclimber which makes the climbing experience possible but also brings limitations
with it. As already stated, the climbing experience became stale because of the pauses
players had to encounter. A possible solution to this issue would be providing higher
rotation speed for the physical wall. However, the game design could also find an in-game
solutions which are discussed in the next subsection. The low participation rate also did
not help with testing the game with people that have no climbing experience at all. This
low diversity of players prevented gathering data about the challenge level of Astroclimb
for non-climbers. A high rate challenge level would also affect usability in a negative way.
The overall gathered data, however, made it clear that unlike in non-VR digital game
design, usability has additional pit-holes if physical activity is involved in a game.
Game feel for traditional video games is described as the intangible, tactile sensation
experienced when the player interacts with video games [158]. This definition changes
for VR games because virtual reality enables the possibility of making the interactions
tangible. Astroclimb is a perfect example where it makes some of the core elements such
as the wall and the climbing holds in the game tangible which enhances the game feel
and immersion directly.
Astroclimb tries to use a decent amount of traditional game design elements in itself such
as story, game mechanics, replayability, challenge, and critical thinking while keeping in
mind that the VR and physical activity aspects of it can influence these game design
elements and require adaptations of these elements.
As the data states all of these game design elements were successfully applied with
different satisfactory levels for the players. The results also show that these applied game
design elements improved immersion for the participants which enabled a higher quality
of user experience. Additionally, the absence of motion sickness helped with giving this
level of quality experience. There were, however, some issues such as occasional imperfect
object alignments and long pauses during the game which affected immersion negatively.
78
5.5. Discussion
5.5 Discussion
The evaluation showed that various game design elements can be applied to the VR
platform, although some of them may need adjustments to make more sense for the
circumstances in the game. The limitations and additional benefits VR platform can
provide should be taken into account to enhance gameplay and increase player satisfaction.
Experienced climbers were less aware of their environment during the climb and noticed
some of the crucial objects in the environment such as the owl extremely late because of
that. As stated in Section 2.3.1, climbers tend to focus on looking forward where the
wall stands and do not pay much attention to their environments. To keep the climbers’
focus on what is important, some of the objects in the environment could be re-allocated
to draw more attention from the players. The used material for the virtual climbing wall,
glass, can be used further for this implementation. The owl could have appeared behind
the wall and the interaction could be designed differently.
One of the issues addressed by the fast climbers was the wait time that had to experience
because of the rolling speed of the climbing wall. An in-game design solution for that
would be forcing the climber to traverse horizontally with some different difficulty levels so
that the rolling speed would stop being an issue to continue climbing. For that particular
solution, a strict and challenging grip path could be made visible to the climber by
changing the grip colors. Moving horizontally would give enough time for the physical
wall to roll down which would eliminate the pauses.
Although the owl was not interpreted realistically, it is clear that the lack of realism does
not have any negative effects on immersion. This idea can be supported further when the
created virtual environment is observed. A hanging climbing wall in the middle of the
space, spaceships warping in and out, the audible sound effects in space, wearing sports
shoes, or change of the nebula in the blink of an eye do not add any realism to the game,
however, the players accept this simulation as it is and the environment makes sense for
them.
Combining physical activity and training with a VR game creates another challenge from
a game design perspective. The game length can easily become an issue if the physical
activity is tiring to an uncomfortable extent. Participants with less climbing experience
stated that the game was tiring but it was not tiring enough to stop playing it. The
tiredness level of the game is also directly proportional to the player’s overall physical
training and condition at that point in time which determines the outcome of the gaming
experience.
Finally, it is also interesting that the players with higher weekly gaming time had fewer
problems with identifying the outcome of the choices that were represented to them
by the owl. It can also be explained with other skills participants possess. The low
participation makes it difficult to make claims about this observation, hence, further
79
5. Evaluation
studies should be conducted in this area to judge the results fairly.
80
CHAPTER 6
Conclusion and Future Work
As part of this master’s thesis, a VR game called Astroclimb based on the project
Vreeclimber was developed and a selection of various game design elements such as
aesthetics, challenge, and replayability that are used for video games were applied.
During the development process, the game went through modifications and adaptations
based on testers’ feedback. In the end, a space-themed game that focuses on climbing
with a unique gameplay was developed.
The literature research has shown that there are already similar approaches to overlay
a real existing climbing wall with virtual content. The applications built upon these
approaches, however, are lacking content and focus on only aligning the digital scene
with the real world. Another limitation of these approaches is the limited climbable area
which is dictated by the height of a real boulder wall. In comparison to these approaches,
successful climbing-based VR games on the market focus on creating VR experiences
with rich content and ignore the real climbing aspect since providing players with a real
climbable terrain or structure would be too expensive or non-profitable. In Astroclimb,
however, the rotation mechanism of the climbing wall enables endless climbing which
creates opportunities to develop games with advanced gameplay logic.
During the development stage of Astroclimb, various game design elements are added to
make the game more compelling to players while keeping them immersed at all stages.
The evaluation results showed that the players found the game aesthetically pleasing, the
gameplay fun due to the application of aforementioned game design elements. The use of
these aspects in harmony increased the level of immersion in the game and the quality of
user experience. Of course, the game is not perfect and needs improvement especially
in terms of gameplay for fast climbers so they do not have to pause climbing because
of reaching the top of the physical wall too quickly. Furthermore, some objects can be
placed better in the virtual environment in order to not create discomfort for the players.
81
6. Conclusion and Future Work
The length of the game is also still problematic although it was shortened once already.
The visible exhaustion of players towards the end of the game shows the game’s overall
difficulty due to its physical activity aspect.
82
APPENDIX A
Step-by-step Test Procedure
1. Operators make sure that the test person followed the Covid-19 procedure until
they entered the workshop.
2. The test person disinfects his hands with the provided hand sanitizer.
3. The test person reads and fills out the declaration of consent, the information
papers, and the pre-climb questionnaire. If they have any questions regarding any
paper, they get answered.
4. VR headset and trackers get disinfected by one of the operators.
5. The test person is asked about their shoe size to provide them with a fitting pair
of climbing shoes.
6. The test person wears the safety suit.
7. Test person sits on a chair and wears climbing shoes. At the same time, the person
gets a briefing about what to expect during the climb. Further questions get
answered if there are any.
8. The VIVE Trackers get attached to climbing shoes by one of the operators.
9. The test person gets informed about how to wear the VIVE Trackers on their hands,
and they follow the instructions.
10. The test person wears the VR headset and stands away from the climbing wall at a
certain point.
11. Safety ropes get attached to the carabiners of the safety suit.
83
A. Step-by-step Test Procedure
12. The test person gets informed about holding their feet and hands with palms
parallel to the ground and fingertips facing straight towards the climbing wall.
(picture)
13. The application starts.
14. Hand and feet calibration commences. After this, the test person gets informed to
move their hands and feet freely again.
15. Wall calibration commences.
16. Once the door of the hanger in the game opens, the test person can start climbing
whenever they want and/or keep observing their surroundings.
17. The test person plays the climbing game which lasts approximately 4 minutes.
18. In the end, the test person can get their hands and feet off the grips.
19. The operator that is responsible for holding the safety ropes of the climber lowers
the climber slowly to the ground.
20. The safety rope gets removed from the carabiners once the test person is on their
feet.
21. The VR headset, VIVE Trackers get removed.
22. The test person gets freed from the safety suit.
23. The test person takes off the climbing shoes.
24. Once the test person is ready, he is asked to fill out the post-climb questionnaire.
25. If the test person has additional remarks towards their current experience a short
interview is conducted.
84
List of Figures
2.1 With the help of the controller the user is able to select a location on the
small globe and fly towards it. [56] . . . . . . . . . . . . . . . . . . . . . . 8
2.2 An interviewer tries out one of the first prototypes of Oculus VR at E3. [42] 9
2.3 A variety of Google Cardboards. [54] . . . . . . . . . . . . . . . . . . . . . 9
2.4 Global VR headset market share, by application, 2020 (%) [130] . . . . . 10
2.5 From left to right: HTC VIVE [178], Sony PlayStation Move [126], Oculus
Touch [118], Valve Index [70] controllers. . . . . . . . . . . . . . . . . . . . 13
2.6 An example for a gaze-based selection cursor in Unity. [94] . . . . . . . . 14
2.7 The potential of VR applications by category. [60] . . . . . . . . . . . . . 15
2.8 Traversing options in Half-Life: Alyx. [11] . . . . . . . . . . . . . . . . . . 17
2.9 The player has to slice cubes with the correct ligtsaber of color. [62] . . . 19
2.10 Players use their avatar hands to interact with various objects. [80] . . . . 19
2.11 The Elemental Tetrad [143] . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
2.12 Interactive cycle in the play experience by Fabricatore [37] . . . . . . . . . 24
2.13 Content-zone diagram for a comfortable user experience [5] . . . . . . . . 27
2.14 Comfortable angles of neck rotation [5] . . . . . . . . . . . . . . . . . . . . 28
2.15 Harness and climbing shoes for indoor climbing. [150] . . . . . . . . . . . 33
2.16 Rope system setup for indoor climbing. [9] . . . . . . . . . . . . . . . . . 33
2.17 What competition looks like in The Climb 2. [25] . . . . . . . . . . . . . . 34
2.18 The climber’s vertical movement on the wall is mostly restricted. [81] . . 34
2.19 VR equipment used for Astroclimb. [176] . . . . . . . . . . . . . . . . . . 35
2.20 The stance the player has to take for calibrating hands and feet. . . . . . 37
4.1 A cross-section of the hangar - the starting point of the game. . . . . . . . 50
4.2 The massive spaceship that brings the player to the climbing wall. . . . . 50
4.3 The mechanical owl designed for Astroclimb. . . . . . . . . . . . . . . . . 52
4.4 The end of first segment in the game. . . . . . . . . . . . . . . . . . . . . 52
4.5 Time and height indicators are placed on the left avatar hand, while the score
is on the right avatar hand. . . . . . . . . . . . . . . . . . . . . . . . . . . 56
4.6 An early design stage of the mechanical owl in Blender. . . . . . . . . . . 58
4.7 The hoverboard designed for players to stand up on before the climb. . . 58
4.8 The moon scene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.9 The asteroid belt scene. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59
4.10 From left to right: The destroyer, Viper, TIE fighter. . . . . . . . . . . . . 59
85
5.1 The Vreeclimber wall. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66
5.2 Operator holding the climber. . . . . . . . . . . . . . . . . . . . . . . . . . 67
5.3 Carabiners with the safety ropes. . . . . . . . . . . . . . . . . . . . . . . . 67
5.4 Extra safety measures with ropes and a robust bar. . . . . . . . . . . . . . 67
5.5 Tracker is hidden between the body and the wall. . . . . . . . . . . . . . . 68
5.6 Tracker is hidden between the hand and the wall. . . . . . . . . . . . . . . 68
5.7 Effects of different game design elements on immersion. . . . . . . . . . . . 71
5.8 Effectiveness of some of the in-game experiences. . . . . . . . . . . . . . . 73
5.9 Effects of the chosen orb on the game experience. . . . . . . . . . . . . . . 73
5.10 Participants’ thoughts on orbs. . . . . . . . . . . . . . . . . . . . . . . . . 75
5.11 Likeliness to play the game again. . . . . . . . . . . . . . . . . . . . . . . 76
5.12 Motivation level to continue climbing after the milestone. . . . . . . . . . 77
86
Bibliography
[1] 360VirtualTour. The White House Virtual Tour. https://www.360virtual
tour.co/portfolio/the-white-house-google-virtual-tour/, 2017.
Online; accessed 18-June-2021.
[2] ADVRTAS. 360 VR is Interactive and Immersive. https://advrtas.com/36
0-vr/, 2021. Online; accessed 18-June-2021.
[3] M. Ahmad. Categorizing Game Design Elements into Educational Game Design
Fundamentals. 11 2019.
[4] A. Alexiou and M. Schippers. Digital game elements, user experience and learning:
A conceptual framework. Education and Information Technologies, 23:2545–2567,
2018.
[5] M. Alger. Visual Design Methods for Virtual Reality. 2015.
[6] Alice. VR Locomotion On Rails. https://www.alice.org/resources/how-
tos/vr-locomotion-on-rails/, 1999–2020. Online; accessed 18-June-2021.
[7] Apple. App store. https://www.apple.com/app-store/. Online; accessed
18-June-2021.
[8] V. A. Art. VR for Galleries: Grow from a local to a global gallery. https:
//vrallart.com/vr-for-galleries/, 2021. Online; accessed 18-June-2021.
[9] B. Bahnke. Simple top rope problem. http://ffden-2.phys.uaf.edu/web
proj/211_fall_2020/Brayden_Bahnke/brayden_bahnke/Slide6.htm.
Online; accessed 18-June-2021.
[10] M. I. Berkman and E. Akan. Presence and Immersion in Virtual Reality, pages
1–10. Springer International Publishing, 2019.
[11] T. Bezmalinovic. Half-Life: Alyx - So trikste valve bei der VR-Fortbewegung.
https://mixed.de/half-life-alyx-so-trickste-valve-bei-der-
vr-fortbewegung/, 2020. Online; accessed 18-June-2021.
87
[12] S. Bjork and J. Holopainen. Patterns in game design. IT Faculty, Göteborgs
universitet, 2004. Page 206.
[13] S. Björk, S. Lundgren, and J. Holopainen. Game Design Patterns. January 2003.
[14] R. Black. Virtual Reality Programs Now Target Pain, Stress, and Depression.
Practical Pain Management - https://www.practicalpainmanagement.
com/patient/virtual-reality-for-pain-depression, 2020. Online;
accessed 18-June-2021.
[15] Blender. Blender - free and open source 3D creation suite. https://www.blen
der.org/, 2021. Online; accessed 04-July-2021.
[16] Blunty. Beat Saber Developer Interview. https://www.youtube.com/watc
h?v=oTmQQVfwOt8, 2018. Online; accessed 18-June-2021.
[17] S. Boiler. Learning Game Design: Game Mechanics. http://www.theknowled
geguru.com/learning-game-design-mechanics/, 2013. Online; accessed
18-June-2021.
[18] D. R. Boyd, D. Gould, M. Hutson, M. Klawunn, D. Laidlaw, J. Chan-Norris, J. Pot-
ter, and H. Rohde. Depth Cues in Virtual Reality and Real World : Understanding.
2000.
[19] W.-P. Brinkman, A. Hoekstra, and R. Vanegmond. The Effect of 3D Audio and
Other Audio Techniques on Virtual Reality Experience. volume 219, January 2015.
[20] E. Chang, H.-T. Kim, and B. Yoo. Virtual reality sickness: A review of causes and
measurements. International Journal of Human-Computer Interaction, 36:1–25, 07
2020.
[21] E. Chang, H. T. Kim, and B. Yoo. Predicting cybersickness based on user’s gaze
behaviors in HMD-based virtual reality. Journal of Computational Design and
Engineering, 8(2):728–739, 2021.
[22] K. Cheng and P. Cairns. Behaviour, realism and immersion in games. pages
1272–1275, 2005.
[23] K. Choi, Y.-J. Yoon, O.-Y. Song, and S.-M. Choi. Interactive and Immersive Learn-
ing Using 360° Virtual Reality Contents on Mobile Platforms. Mobile Information
Systems, 2018:1–12, 10 2018. doi: 10.1155/2018/2306031.
[24] ConcernedApe. Stardew valley. https://www.stardewvalley.net/. Online;
accessed 18-June-2021.
[25] Crytek. The climb 2. https://www.theclimbgame.com/. Online; accessed
18-June-2021.
88
[26] A. Dancu. The Ultimate Display. Technical report, Chalmers University of
Technology, 2014.
[27] David. How Virtual and Augmented Reality Help to Cut Costs. Vection - https:
//www.vection.com.au/news/post/how-virtual-and-augmented-r
eality-help-cut-costs, 2021. Online; accessed 18-June-2021.
[28] H. Desurvire and M. Kreminski. Are Game Design and User Research Guidelines
Specific to Virtual Reality Effective in Creating a More Optimal Player Experience?
Yes, VR PLAY, pages 40–59. 2018.
[29] N. Didehbani, T. Allen, M. Kandalaft, D. Krawczyk, and S. Chapman. Virtual
Reality Social Cognition Training for children with high functioning autism. vol-
ume 62, pages 703–711, 2016. URL https://www.sciencedirect.com/sc
ience/article/pii/S0747563216303089.
[30] M. Domenech Lopez. How can i get there? Disorientation and motion sickness
effects depending on the virtual reality navigation technique. 2020.
[31] S. Dredge. Facebook closes its $2bn Oculus Rift acquisition. What next? The
Guardian - https://www.theguardian.com/technology/2014/jul/22
/facebook-oculus-rift-acquisition-virtual-reality, July 2014.
Online; accessed 18-June-2021.
[32] A. Dublin. 23 museums, attractions, and theme parks you can visit virtually
including the Louvre, San Diego Zoo, Great Wall of China, and The Wizarding
World of Harry Potter. https://www.businessinsider.com/virtual-
museums-theme-parks-activities?r=DE&IR=T, 2020. Online; accessed
18-June-2021.
[33] E3. E3 expo. https://e3expo.com/, 2012. Online; accessed 18-June-2021.
[34] H. Eidenberger. Jumpcube Project - Technical University of Vienna. http:
//www.jumpcu.be/, 2015. Online; accessed 18-June-2021.
[35] H. Eidenberger. VreeClimber Project - Technical University of Vienna. http:
//www.vreeclimber.at/, 2020. Online; accessed 18-June-2021.
[36] Eurogamer. What Remains of Edith Finch. http://edithfinch.com/. Online;
accessed 18-June-2021.
[37] C. Fabricatore. Gameplay and game mechanics design: a key to quality in
videogames. 10 2007.
[38] G. Falloon. Using avatars and virtual environments in learning: What do they
have to offer? British Journal of Educational Technology, 41(1):108–122, 2010. doi:
https://doi.org/10.1111/j.1467-8535.2009.00991.x. URL https://bera-journ
als.onlinelibrary.wiley.com/doi/abs/10.1111/j.1467-8535.20
09.00991.x.
89
[39] M. Fitzsimmons. Sony reveals PS4 VR headset at GDC 2014. techradar - https:
//www.techradar.com/news/gaming/sony-reveals-it-s-been-d
eveloping-vr-at-gdc-2014-1234976, March 2014. Online; accessed
18-June-2021.
[40] O. for Developers. Understanding Gameplay Latency for Oculus Quest, Oculus
Go and Gear VR. https://developer.oculus.com/blog/understandin
g-gameplay-latency-for-oculus-quest-oculus-go-and-gear-vr/.
Online; accessed 18-June-2021.
[41] J. Fu. The Influence of Background Music of Video Games on Immersion. Journal
of Psychology & Psychotherapy, 05, 2015.
[42] Gamereactor. E3 12: John Carmac’s VR Presentation. https://www.youtube.
com/watch?v=kw-DlWwlXHo, July 2012. Online; accessed 18-June-2021.
[43] B. Games. Beat saber. https://store.steampowered.com/app/620980/
Beat_Saber/, 2018. Online; accessed 18-June-2021.
[44] E. Games. Unreal Engine. https://www.unrealengine.com/, . Online;
accessed 18-June-2021.
[45] F. Games. The Room. https://www.fireproofgames.com/games/the-r
oom, . Online; accessed 18-June-2021.
[46] F. Games. The Room VR: A Dark Matter. https://store.steampowered.c
om/app/1104380/The_Room_VR_A_Dark_Matter/, 2020. Online; accessed
18-June-2021.
[47] N. P. Gerald Lynch. Best VR headset 2021: Oculus Quest 2, PSVR, Valve Index
and more. techradar - https://www.techradar.com/news/the-best-vr
-headset, 2021. Online; accessed 18-June-2021.
[48] A. Giddens. Notes on the Concepts of Play and Leisure. The Sociological Review,
12(1), 1964. Page: 75.
[49] L. K. Goode. Synesthesia : a sixth sense or a sensation : a research project based
upon interviewing persons with color synesthesia. 2010.
[50] Google. Daydream. https://vr.google.com/daydream. Online; accessed
18-June-2021.
[51] Google. Google earth. https://www.google.com/earth/, 2001. Online;
accessed 18-June-2021.
[52] Google. Google maps. https://www.google.com/maps, 2005. Online;
accessed 18-June-2021.
90
[53] Google. Google street view. https://www.google.com/streetview/, 2007.
Online; accessed 18-June-2021.
[54] Google. Get your Cardboard. https://arvr.google.com/cardboard/get-
cardboard/, 2014. Online; accessed 18-June-2021.
[55] Google. Google cardboard. https://arvr.google.com/cardboard/, June
2014. Online; accessed 18-June-2021.
[56] Google. Google Earth VR. https://arvr.google.com/earth/, 2021. Online;
accessed 18-June-2021.
[57] I. Granic, A. Lobel, and R. Engels. The benefits of playing video games. The
American psychologist, 69 1:66–78, 2014.
[58] C. Greg. I Have No Words & I Must Design: Toward a Critical Vocabulary for
Games. In Computer Games and Digital Cultures Conference Proceedings. Tampere
University Press, June 2002. Page 22.
[59] B. Halliwell. Understanding Auto Belays. https://www.theclimbingguy.c
om/understanding-auto-belays/, 2020. Online; accessed 18-June-2021.
[60] S. T. Help. Future of Virtual Reality - Market Trends And Challenges. https:
//www.softwaretestinghelp.com/future-of-virtual-reality/,
2021. Online; accessed 18-June-2021.
[61] S.-F. Henrik. The Player Engagement Process - An Exploration of Continuation
Desire in Digital Games. In DiGRA &#3911 - Proceedings of the 2011 DiGRA
International Conference: Think Design Play. DiGRA/Utrecht School of the Arts,
2011.
[62] H. Hermann. Oculus kauft Beat-Saber-Entwickler. https://www.gamersgl
obal.de/news/167437/oculus-kauft-beat-saber-entwickler, 2019.
Online; accessed 18-June-2021.
[63] U. S. Hollywood. Jurassic Park - The Ride. https://www.universalstudi
oshollywood.com/web/en/us/things-to-do/rides-and-attractio
ns/jurassic-world, 2021. Online; accessed 18-June-2021.
[64] IMDb. Battlestar Galactica. https://www.imdb.com/title/tt0407362/,
2021. Online; accessed 04-July-2021.
[65] IMDb. Back to the Future. https://www.imdb.com/title/tt0088763/,
2021. Online; accessed 04-July-2021.
[66] IMDb. Dark Star. https://www.imdb.com/title/tt0069945/, 2021.
Online; accessed 07-July-2021.
91
[67] IMDb. Star wars. https://www.imdb.com/star-wars/, 2021. Online;
accessed 04-July-2021.
[68] V. Inc. Omni by virtuix. https://www.virtuix.com/accessories/.
Online; accessed 18-June-2021.
[69] J. Incao. How VR is Transforming the Way We Train Associates. Walmart
- https://corporate.walmart.com/newsroom/innovation/2018
0920/how-vr-is-transforming-the-way-we-train-associates,
September 2018. Online; accessed 18-June-2021.
[70] V. Index. Controllers. https://www.valvesoftware.com/en/index/con
trollers, 2019. Online; accessed 18-June-2021.
[71] V. Index. Valve index headset. https://www.valvesoftware.com/en/ind
ex/headset, 2019. Online; accessed 18-June-2021.
[72] F. B. Insights. Market research report. https://www.fortunebusinessins
ights.com/industry-reports/virtual-reality-in-education-ma
rket-101696, November 2019. Online; accessed 18-June-2021.
[73] F. B. Insights. Virtual Reality in Gaming Market Size, Share & Covid-19 Impact
Analysis, By Component (Hardware, Software and Content), By Device (Mobile,
Console/PC and Standalone), and Regional Forecast, 2020-2027. 2020.
[74] D. Jagneaux. Developers Test Running in Place To Solve VR’s Movement Problem.
https://uploadvr.com/running-in-place-movement-locomotion-
vr-developers/, 2016. Online; accessed 18-June-2021.
[75] Jay. Field of View for Virtual Reality Headsets Explained. VR Lens Lab: Virtual
Reality Knowledge - https://vr-lens-lab.com/field-of-view-for-vi
rtual-reality-headsets/, March 2016. Online; accessed 18-June-2021.
[76] H. Kaufmann and T. Cacmak. The Virtualizer - A New Locomotion Device.
https://www.ims.tuwien.ac.at/projects/virtualizer, 2013–2015.
Online; accessed 18-June-2021.
[77] Kickstarter. Oculus Rift: Step Into the Game. https://www.kickstarter.
com/projects/1523379957/oculus-rift-step-into-the-game, 2012.
Online; accessed 18-June-2021.
[78] E. Kidwell. How to avoid motion sickness caused by VR headsets while gaming.
Windows Central - https://www.windowscentral.com/how-avoid-mot
ion-sickness-caused-by-vr-headsets-while-gaming, April 2018.
Online; accessed 18-June-2021.
92
[79] J. Kim. Get a closer look with Street View in Google Earth VR. https:
//blog.google/products/google-ar-vr/get-closer-look-street
-view-google-earth-vr/, September 2017. Online; accessed 18-June-2021.
[80] M. Kleffmann. The Room VR: A Dark Matter - VR-Rätsel-Abenteuer erscheint
Ende März. https://www.4players.de/4players.php/spielinfone
ws/Allgemein/41596/2188451/The_Room_VR_A_Dark_Matter-VR-Rae
tsel-Abenteuer_erscheint_Ende_Maerz.html, 2020. Online; accessed
18-June-2021.
[81] F. Kosmalla, A. Zenner, M. Speicher, F. Daiber, N. Herbig, and A. Krüger.
Exploring Rock Climbing in Mixed Reality Environments. pages 1787–1793, 2017.
[82] B. Kuchera. The Room VR: A Dark Matter fulfills the promise of VR puzzle games.
https://www.polygon.com/reviews/2020/3/27/21196839/the-roo
m-vr-review-oculus-quest-rift-playstation-vr-vive-valve-in
dex, 2020. Online; accessed 18-June-2021.
[83] G. Kumparak. A Brief History of Oculus. https://techcrunch.com/201
4/03/26/a-brief-history-of-oculus/, March 2014. Online; accessed
18-June-2021.
[84] C. Lai, X. Hu, A. Segismundo, A. Phadke, and R. P. McMahan. The Comfort
Benefits of Gaze-Directed Steering. In 2020 IEEE International Symposium on
Mixed and Augmented Reality Adjunct (ISMAR-Adjunct), pages 102–103, 2020.
[85] S. Laitinen. Better Games Through Usability Evaluation and Testing. https:
//www.gamasutra.com/view/feature/130745/better_games_throu
gh_usability_.php?print=1, 2005. Online; accessed 12-July-2021.
[86] A. LaMeyer. An Update on Concerts in VR - Progress, But Not Perfection.
https://amylameyer.medium.com/an-update-on-concerts-in-vr-
progress-but-not-perfection-e3fc6772a7a7, September 2019. Online;
accessed 18-June-2021.
[87] B. Lang. GDC 2014: Oculus Rift Developer Kit 2 (dk2) Pre-orders Start Today
for $350, Ships in July. Road to VR https://www.roadtovr.com/oculus-
rift-developer-kit-2-dk2-pre-order-release-date-specs-gdc-
2014/, 2014. Online; accessed 18-June-2021.
[88] B. Lang. Social VR App ’VRChat’ is Seeing Record Usage Amidst the Pandemic.
Road To VR - https://www.roadtovr.com/vrchat-record-users-cor
onavirus/, 2020. Online; accessed 18-June-2021.
[89] B. Lang. Half-Life: Alyx Has Become Steam’s Best & Most Rated VR Game Less
Than a Year After Launch. https://www.roadtovr.com/half-life-aly
x-steam-best-most-rated-game/, 2020. Online; accessed 18-June-2021.
93
[90] E. Langbehn, P. Lubos, G. Bruder, and F. Steinicke. Application of redirected
walking in room-scale vr. In 2017 IEEE Virtual Reality (VR), pages 449–450, 2017.
[91] S. M. LaValle. Virtual Reality. In Chapter 10 Interaction, pages 283–312. Cambridge
University Press, 2015.
[92] S. M. LaValle. Virtual Reality. In Chapter 9 Tracking, pages 245–282. Cambridge
University Press, 2015.
[93] R. Lavoie, K. Main, and C. King. Virtual experience, real consequences: the
potential negative emotional consequences of virtual reality gameplay. In Virtual
Reality, 2021.
[94] F. Learn. Interaction techniques in VR. https://www.futurelearn.com/in
fo/courses/construct-a-virtual-reality-experience/0/steps/
96390, 2020. Online; accessed 18-June-2021.
[95] C.-C. Lee, K.-L. Hsiao, and C.-C. Chen. Exploring the benefit and sacrifice factors
of virtual reality gameplay. Frontiers in Psychology, 11:251, 2020. ISSN 1664-1078.
doi: 10.3389/fpsyg.2020.00251. URL https://www.frontiersin.org/arti
cle/10.3389/fpsyg.2020.00251.
[96] A. Lund. Norn. https://www.alexanderlund.se/norn/. Online; accessed
18-June-2021.
[97] A. Lund. Is Seeing Believing? A Study in Virtual Realities, Immersion and Game
Design. 2017.
[98] P. Machine. Rules vs Mechanics. https://problemmachine.wordpress.com
/2013/05/27/rules-vs-mechanics/, 2013. Online; accessed 18-June-2021.
[99] N. Machner. Virtual Climbing Application. Master’s Thesis - Vienna University
of Technology, 2018.
[100] S. Macy. Microsoft Flight Simulator Review. https://www.ign.com/arti
cles/microsoft-flight-simulator-review, 2021. Online; accessed
18-June-2021.
[101] Manus. Prime II Motion Capture Gloves. https://www.manus-vr.com/moc
ap-gloves, 2020. Online; accessed 18-June-2021.
[102] D. Mason. What is motion sickness in video games and how can you prevent it?
KITGURU - https://www.kitguru.net/gaming/damien-cox/what-is-
motion-sickness-in-video-games-and-how-can-you-prevent-it/,
July 2018. Online; accessed 18-June-2021.
[103] M. Matamala-Gomez, T. Donegan, S. Bottiroli, G. Sandrini, M. V. Sanchez-Vives,
and C. Tassorelli. Immersive Virtual Reality and Virtual Embodiment for Pain
Relief. Frontiers in Human Neuroscience, 13:279, 2019.
94
[104] S. Matovina and E. Johns. World’s First Virtual Reality Department Store.
https://www.ebayinc.com/stories/press-room/au/worlds-first
-virtual-reality-department-store/, 2006. Online; accessed 18-June-
2021.
[105] MDB. TRON: Legacy. https://www.imdb.com/title/tt1104001/?ref
_=nv_sr_srsg_0, 2010. Online; accessed 18-June-2021.
[106] A. Meban. Immersive storytelling placing viewers beside refugees in boats, camps
& detention centres. focus on refugees - https://focusonrefugees.org/im
mersive-storytelling-placing-viewers-beside-refugees-in-bo
ats-camps-detention-centres/, June 2016. Online; accessed 18-June-2021.
[107] E. Mellou. Play Theories: A contemporary review. Early Child Development and
Care, 102(1):91–100, 1994.
[108] Microsoft. Flight simulator. https://www.flightsimulator.com/, 2020.
Online; accessed 18-June-2021.
[109] S. Miklaucic. John Carmack. Encyclopedia Britannica - https://www.brit
annica.com/biography/John-Carmack, August 2020. Online; accessed
18-June-2021.
[110] L. Nacke. Acagamic. In The formal systems of games and game design atoms, 2014.
Retrieved from https://acagamic.com/courses/intro-to-game-desig
n/the-formal-systems-of-games-and-game-design-atoms/.
[111] NASA. 3D resources. https://nasa3d.arc.nasa.gov/models, 2021.
Online; accessed 04-July-2021.
[112] T. Nemeth. English Knight. In Gamifying the EFL Classroom (Unpublished master’s
thesis), 2015. Retrieved from https://ludus.hu/en/gamification/.
[113] J. Nguyen, C. Smith, Z. Magoz, and J. Sears. Screen door effect reduction using
mechanical shifting for virtual reality displays. In B. C. Kress and C. Peroz, editors,
Optical Architectures for Displays and Sensing in Augmented, Virtual, and Mixed
Reality (AR, VR, MR), pages 200 – 210. International Society for Optics and
Photonics, SPIE, 2020.
[114] J. Nolan, D. Harley, A. Walsh, and E. McQuiggan. Emerging Trends in Virtual
Reality for Gaming: an assessment of best practices from research and development
in the gaming industry.
[115] Oculus. Oculus store. https://www.oculus.com/experiences/rift/.
Online; accessed 18-June-2021.
95
[116] Oculus. Oculus Guardian System. https://developer.oculus.com/doc
umentation/native/pc/dg-guardian-system/, 2016. Online; accessed
18-June-2021.
[117] Oculus. Experience the next level of wireless vr. https://www.oculus.com/g
o/, May 2018. Online; accessed 18-June-2021.
[118] Oculus. Accessorie & Parts. https://www.oculus.com/quest/accessori
es/, 2019. Online; accessed 18-June-2021.
[119] Oculus. Explore oculus quest. https://www.oculus.com/quest/feature
s/, 2019. Online; accessed 18-June-2021.
[120] P. A. Pallavicini F. Virtual Reality Games and the Role of Body Involvement
in Enhancing Positive Emotions and Decreasing Anxiety: Within-Subjects Pilot
Study. In JMIR serious games, 2020.
[121] M. Pavlovich. The Role of Playtesting in Game Design. https://www.gamespre
cipice.com/role-of-playtesting/, 2014. Online; accessed 18-June-2021.
[122] C. Petrov. 43 virtual reality statistics that will rock the market in 2021. techjury
- https://techjury.net/blog/virtual-reality-statistics/, May
2021. Online; accessed 18-June-2021.
[123] M. Phan, J. Keebler, and B. Chaparro. The Development and Validation of the
Game User Experience Satisfaction Scale (guess). Human Factors: The Journal of
the Human Factors and Ergonomics Society, 58, 2016.
[124] D. Pickell. The 7 Stages of Game Development. https://www.g2.com/artic
les/stages-of-game-development, 2019. Online; accessed 18-June-2021.
[125] G. Play. Google Store. https://play.google.com/store. Online; accessed
18-June-2021.
[126] PlayStation. PS VR accessories. https://www.playstation.com/en-us/
ps-vr/accessories/, 2016. Online; accessed 18-June-2021.
[127] S. Pradeep, A. Alexander, S. Narayanan, and N. Polys. Immersion and Engagement
in a VR Game. Virginia Tech, 2016.
[128] X. qin Chang, D. hua Zhang, and X. xin Jin. Application of virtual reality
technology in distance learning. International Journal of Emerging Technologies in
Learning (iJET), 11(11):76–79, 2016. ISSN 1863-0383. URL https://online
-journals.org/index.php/i-jet/article/view/6257.
[129] P. Raut. Analysis of immersive virtual reality vs. desktop 3D games. Boston,
Massachusetts : Northeastern University, 2018.
96
[130] V. R. M. Report. Virtual Reality Headset Market Size, Share & Trends Anal-
ysis Report By End-device (Low-end, High-end), By Product Type (Standalone,
Smartphone-enabled), By Application (Gaming, Education), And Segments Fore-
casts, 2021 - 2028. Grand View Research, 2021.
[131] S. D. Resort. TRON Lightcycle Power Run - Presented by Chevrolet. https:
//www.shanghaidisneyresort.com/en/attractions/tron-lightcy
cle-power-run/, 2021. Online; accessed 18-June-2021.
[132] H. Reynolds. Three simple (but not obvious) tips on playtesting. https://mojo
-nation.com/three-simple-not-obvious-tips-playtesting/, 2019.
Online; accessed 18-June-2021.
[133] A. Riviere. How do you design your VR game around motion sickness constraints.
Gamasutra, 2017.
[134] A. Robertson. HTC VIVE Review. The Verge - https://www.theverge.c
om/2016/4/5/11358618/htc-vive-vr-review, 2016. Online; accessed
18-June-2021.
[135] K. Rogers, G. Ribeiro, R. Wehbe, M. Weber, and L. Nacke. Vanishing Importance:
Studying Immersive Effects of Game Audio Perception on Player Experiences in
Virtual Reality. pages 1–13, 2018.
[136] A. Romano. Stuck at Home? These 12 Famous Museums Offer Virtual Tours You
Can Take on Your Couch. Travel Leisure - https://www.travelandleisure
.com/attractions/museums-galleries/museums-with-virtual-to
urs, 2020. Online; accessed 18-June-2021.
[137] D. Rudin. The stock market’s roller coaster metaphor becomes literal thanks to VR.
Kill Screen - https://killscreen.com/previously/articles/stock
-markets-roller-coaster-metaphor-becomes-literal-thanks-vr/,
April 2015. Online; accessed 18-June-2021.
[138] RYOT. Solitary confinement in 360 virtual reality. https://www.youtube.co
m/watch?v=nDwulYcboDU, September 2015. Online; accessed 18-June-2021.
[139] Samsung. Gear VR. https://www.samsung.com/global/galaxy/gear-v
r/, 2015. Online; accessed 18-June-2021.
[140] A. Savage. Inside Valve: Making Half-Life: Alyx for Virtual Reality. https:
//www.youtube.com/watch?v=cRVXhA0-TI4, 2020. Online; accessed 18-
June-2021.
[141] J. Schell. The Art of Game Design: A book of lenses. Taylor & Francis, 2008. Page
30.
97
[142] J. Schell. The Art of Game Design: A book of lenses. Taylor & Francis, 2008. Page
37.
[143] J. Schell. The Art of Game Design: A book of lenses. Taylor & Francis, 2008.
[144] ScienceDaily. Human Brain Loves Surprises, Research Reveals. Emory University
Health Sciences Center - https://www.sciencedaily.com/releases/20
01/04/010415224316.htm, 2021. Online; accessed 18-June-2021.
[145] V. Sense. VIVE Pro Specs & User Guide. https://developer.vive.com/r
esources/vive-sense/hardware-guide/vive-pro-specs-user-gui
de/. Online; accessed 18-June-2021.
[146] W. Shelstad, D. Smith, and B. Chaparro. Gaming on the Rift: How Virtual Reality
Affects Game User Satisfaction. Proceedings of the Human Factors and Ergonomics
Society Annual Meeting, pages 2072–2076, 2017.
[147] D. Shin and S.-i. Kim. Homo Curious: Curious or Interested? Educational
Psychology Review, 2019.
[148] N. Simon. What We Talk About When We Talk About Game Aesthetics. In
Proceedings of the 2009 DiGRA International Conference: Breaking New Ground:
Innovation in Games, Play, Practice and Theory. Brunel University, September
2009.
[149] A. Skandalis. Virtual reality has been boosted by coronavirus - here’s how to
avoid it leading us to dystopia. The Conversation - https://theconversatio
n.com/virtual-reality-has-been-boosted-by-coronavirus-here
s-how-to-avoid-it-leading-us-to-dystopia-141073, 2020. Online;
accessed 18-June-2021.
[150] I. Staff. Inspire News and Articles. https://inspirerock.com/blog/ins
piring-gear-scarpa-helix-shoes-black-diamond-solution-harn
esses/. Online; accessed 18-June-2021.
[151] Steam. Half-Life: Alyx. https://store.steampowered.com/app/546560/
HalfLife_Alyx/. Online; accessed 18-June-2021.
[152] Steam. Games with Space-Tag. https://store.steampowered.com/searc
h/?term=space, 2021. Online; accessed 24-June-2021.
[153] S. Store. Lucid Trips. https://store.steampowered.com/app/389260/
Lucid_Trips/, 2017. Online; accessed 18-June-2021.
[154] S. Store. To The Top. https://store.steampowered.com/app/509250/
TO_THE_TOP/, 2017. Online; accessed 18-June-2021.
98
[155] S. Support. SteamVR Chaperone FAQ. https://support.steampower
ed.com/kb_article.php?ref=6281-TOKV-4722, 2021. Online; accessed
12-July-2021.
[156] D. Swinhart. Virtual reality has real problems. Here’s how game developers seek
to delete them. https://www.washingtonpost.com/video-games/2021/
01/21/virtual-reality-2021/, 2021. Online; accessed 18-June-2021.
[157] S. Swink. Game Feel: The Secret Ingredient. https://www.gamasutra.com/
view/feature/130734/game_feel_the_secret_ingredient.php, 2007.
Online; accessed 20-June-2021.
[158] S. Swink. Game Feel: A Game Designer’s Guide to Virtual Sensation. Amsterdam,
Boston: Morgan Kaufmann Publishers/Elsevier, 2008.
[159] Y. Takahashi and A. Murata. Change of equilibrium under the influence of VR
experience. In Proceedings 10th IEEE International Workshop on Robot and Human
Interactive Communication, pages 642–647, 2001.
[160] J. Taylor. Virtual reality and the changing face of surgery. https://www.st
andard.co.uk/futurelondon/health/virtual-reality-in-surger
y-a3998166.html, 2018. Online; accessed 18-June-2021.
[161] U. Technologies. Unity Game Engine. https://unity.com/. Online; accessed
18-June-2021.
[162] A. Thompson. The Importance of Video Game Narrative. https://sbanimat
ion.com/the-importance-of-video-game-narrative/, 2021. Online;
accessed 18-June-2021.
[163] S. Thompson. Motion Sickness in VR: Why it happens and how to minimise it.
https://virtualspeech.com/blog/motion-sickness-vr, 2020. Online;
accessed 18-June-2021.
[164] P. Thurrott. Over 2 Million People Have Played Microsoft Flight Simulator.
https://www.thurrott.com/games/245159/over-2-million-peopl
e-have-played-microsoft-flight-simulator, 2020. Online; accessed
18-June-2021.
[165] O. Tiilikainen. The Pros & Cons of Virtual Reality in L&D. Valamis - https:
//www.valamis.com/blog/pros-and-cons-of-virtual-reality,
2021. Online; accessed 18-June-2021.
[166] ultraleap. Leap Motion Controller. https://www.ultraleap.com/product/
leap-motion-controller/, 2013. Online; accessed 18-June-2021.
99
[167] T. Unige. Game Design Patterns. https://tecfa.unige.ch/tecfa/mal
tt/VIP/Ressources/Articles/Game%20Design%20Patterns/collec
tion/Alphabetical_Patterns/CognitiveImmersion.htm, . Online;
accessed 18-June-2021.
[168] T. Unige. Game Design Patterns. https://tecfa.unige.ch/tecfa/maltt
/VIP/Ressources/Articles/Game%20Design%20Patterns/collecti
on/Alphabetical_Patterns/ConsistentRealityLogic.htm, . Online;
accessed 18-June-2021.
[169] T. Unige. Game Design Patterns. https://tecfa.unige.ch/tecfa/m
altt/VIP/Ressources/Articles/Game%20Design%20Patterns/co
llection/Alphabetical_Patterns/Downtime.htm, . Online; accessed
18-June-2021.
[170] T. Unige. Game Design Patterns. https://tecfa.unige.ch/tecfa/m
altt/VIP/Ressources/Articles/Game%20Design%20Patterns/co
llection/Alphabetical_Patterns/Downtime.htm, . Online; accessed
18-June-2021.
[171] Unity. Unity Manual: Coroutines. https://docs.unity3d.com/Manual/Co
routines.html, 2021. Online; accessed 08-July-2021.
[172] Valve. Steam store. https://store.steampowered.com/. Online; accessed
18-June-2021.
[173] L. Vanacken, T. Grossman, and K. Coninx. Multimodal selection techniques for
dense and occluded 3d virtual environments. Int. J. Hum.-Comput. Stud., 67(3):
237–255, Mar. 2009. ISSN 1071-5819. doi: 10.1016/j.ijhcs.2008.09.001. URL
https://doi.org/10.1016/j.ijhcs.2008.09.001.
[174] E. Vasina. 7 Steps You Must Take to Succeed in VR Game Development. IT Craft
- https://itechcraft.com/blog/vr-game-development/, 2021. Online;
accessed 18-June-2021.
[175] VIVE. VIVE Tracker Developer Guidelines. https://developer.vive.com
/resources/vive-sense/hardware-guide/vive-tracker-develope
r-guidelines/, . Online; accessed 18-June-2021.
[176] VIVE. VIVE Products. https://www.vive.com/us/product/, . Online;
accessed 18-June-2021.
[177] VIVE. Viveport. https://www.viveport.com/, . Online; accessed 18-June-
2021.
[178] VIVE. Vive Controller. https://www.vive.com/eu/accessory/controll
er/, 2016. Online; accessed 18-June-2021.
100
[179] VIVE. Vive Tracker. https://www.vive.com/eu/accessory/vive-tra
cker/, 2017. Online; accessed 18-June-2021.
[180] C. VR. Curriculum-aligned Virtual, Augmented & Mixed Reality Content. https:
//www.classvr.com/school-curriculum-content-subjects/, 2021.
Online; accessed 18-June-2021.
[181] O. VR. The Leading Virtual Reality Surgical Training & Assessment Platform.
https://ossovr.com/, 2021. Online; accessed 18-June-2021.
[182] T. Wien. Coronavirus: Rules of conduct at TU Wien. https://www.tuwien.a
t/en/tu-wien/corona, 2021. Online; accessed 12-July-2021.
[183] P.-M. Wiki. Pac-man. https://pacman.fandom.com/wiki/Pac-Man.
Online; accessed 18-June-2021.
[184] A. M. Winderl. Indoor Rock Climbing 101; Everything You Need to Know Before
Your First Visit to the Climbing Gym. SELF - https://www.self.com/sto
ry/indoor-rock-climbing-101, 2019. Online; accessed 18-June-2021.
[185] Youtube. Benson Arizona - John Yager. https://www.youtube.com/watc
h?v=WCoqOCvhSR0, 2014. Online; accessed 07-July-2021.
[186] Youtube. Echoes - Pink Floyd. https://www.youtube.com/watch?v=KBc
a3xf-j3o, 2015. Online; accessed 07-July-2021.
[187] Youtube. Mr. Spaceman - The Byrds. https://www.youtube.com/watch?v
=3KFTm9vmZDI, 2021. Online; accessed 07-July-2021.
101