UNIVERSITY CAMPUS SUFFOLK Developing Gameplay Mechanics for Head-Tracked Stereoscopy: A Feasibility Study B.Sc. (Hons) Computer Games Programming Roger Creyke (s110431) 14th May 2010 This text investigates the feasibility and limitations of developing gameplay mechanics for modern three dimensional game environments, specifically with tracked stereoscopic imaging via the use of a virtual reality head mounted display. Developing Gameplay Mechanics for Head-Tracked Stereoscopy Roger Creyke (s110431) Acknowledgements I would very much like to thank: My wife Rachel for her support, patience, love and everything in between. My parents for their love, support, and tolerance of my academic procrastination. My programming tutor Dr Andrew Revitt for his enthusiasm and encouragement. My dissertation tutors Chris Janes and Robert Kurta for their guidance. My colleagues Alex Webb, Matt David and Daniel Stamp for their help with proof reading. 14th May 2010 Page 2 Developing Gameplay Mechanics for Head-Tracked Stereoscopy Roger Creyke (s110431) Contents 1 Introduction .......................................................................................................................................... 4 1.1 Central Problematic .............................................................................................................................. 4 1.2 Aims and Objectives .............................................................................................................................. 4 2 Literature Review .................................................................................................................................. 5 2.1 Stereoscopy ........................................................................................................................................... 5 2.2 Tracking ................................................................................................................................................. 7 2.3 Head Mounted Displays ........................................................................................................................ 9 3 Research .............................................................................................................................................. 11 3.1 Principle Research Objectives ............................................................................................................. 11 3.2 Research Method ................................................................................................................................ 11 3.2.1 Installation ...................................................................................................................................... 11 3.2.2 Interfacing ....................................................................................................................................... 11 3.2.3 Testbed ........................................................................................................................................... 12 3.2.4 Gameplay Mechanics ...................................................................................................................... 13 4 Conclusion ........................................................................................................................................... 16 4.1 Findings ............................................................................................................................................... 16 4.2 Summary & Recommendations .......................................................................................................... 16 4.3 Further Development .......................................................................................................................... 16 5 Bibliography ........................................................................................................................................ 17 6 Table of Figures ................................................................................................................................... 19 7 Glossary of Terms ................................................................................................................................ 20 8 Table of Software ................................................................................................................................ 21 9 Appendices .......................................................................................................................................... 22 9.1 Project Plan ......................................................................................................................................... 22 9.2 Headset Interface Code ....................................................................................................................... 23 9.2.1 Headset.cs ....................................................................................................................................... 23 9.2.2 HeadsetEye.cs ................................................................................................................................. 29 9.2.3 HeadsetMeasurement.cs ................................................................................................................ 30 14th May 2010 Page 3 Developing Gameplay Mechanics for Head-Tracked Stereoscopy Roger Creyke (s110431) 1 Introduction Virtual reality head mounted displays are head mounted devices which usually project a three dimensional image to the user via the use of stereoscopic visual displays and monitor the user’s movements via the use of tracking devices. A stereoscopic visual display is a device which displays two images, usually taken from offset angles, to give the illusion of depth. A tracking device is a piece of hardware which monitors the movement of its user. The application of virtual reality head mounted displays (HMDs) within the field of interactive entertainment is not a new proposition, but while such systems have been trialled commercially for over 20 years, they have yet to be adopted by the mainstream consumer market. This paper documents an investigation into the history of head mounted stereoscopy and attempts to clarify why the games industry has been hesitant to embrace the technology by understanding the limitations of, and difficulties with, developing tracked stereoscopic gameplay mechanics. Specifically, the development processes required to create a modern interactive application are investigated for such systems. Finally, presented are a number of new potential gameplay mechanics designed for stereoscopic HMDs. This paper outlines a number of methods available for implementing head mounted virtual reality. Firstly, the science of stereoscopy is investigated with the intention of understanding how users perceive depth, and what methods can be used to create an artificial sense of perspective. Secondly, the science of tracking is explored in detail, with the intention of understanding the optimum method available for delivering a convincing yet practical interactive experience. Research into the practical creation of two gameplay mechanics is discussed in detail along with both initial and retrospective observations of notable difficulties during development. Development of a custom headset interface library is also documented. Source code for the library is included, fully annotated and available for use in similar projects. Finally, a conclusion is presented, with recommendations for those who may be considering pursuing stereoscopic tracked gameplay development. This outlines limitations of the concept, workarounds for potential issues and an overall assessment of the feasibility of such an undertaking. 1.1 Central Problematic To understand the practicalities, difficulties and limitations of developing gameplay mechanics for head tracked stereoscopic vision, with the intention of deciding whether this technology is widely suitable to the field of interactive entertainment. 1.2 Aims and Objectives This research project was chosen with the intention of achieving the following goals: To understand the science behind stereoscopy and head tracking. To develop a custom process for prototyping gameplay mechanics with an HMD. To apply knowledge garnered from the undergraduate degree course. To satisfy a personal interest in the subject matter. 14th May 2010 Page 4 Developing Gameplay Mechanics for Head-Tracked Stereoscopy Roger Creyke (s110431) 2 Literature Review 2.1 Stereoscopy “A visual display channel is a presentation of visual information displayed for one eye. Two visual display channels with separate views are required to achieve stereopsis.” (Sherman, 2003, p. 124) Stereoscopy is a broad term which defines any technique capable of recording three-dimensional visual information of an object or scene from dual observation points (see Figure 1). The ability to judge distance from the point of the observer through the use of this binocular vision is known as stereopsis. Kim argues that humans are 3D-orientated creatures, and operate daily using the depth perception capability in the immediate space around them. Consequently, providing depth information is important in realising 3D and natural interaction in the virtual environment (Kim, 2005, p. 81). Figure 1 - Stereoscopy Human beings exist or at least perceive to exist in a three dimensional environment and can perceive depth relative to their point of observation by using natural stereoscopic