Virtual Reality Headsets - A Theoretical and Pragmatic Approach

Philippe Fuchs

• Verlag: CRC Press
• Jahr: 2017
• ISBN:
  9781351803069
• Auflage: 1
• Thema: Computer Science
• Thema: Computer Graphics

The purpose of virtual reality is to make possible a sensorimotor and cognitive activity for a user in a digitally created artificial world. Recent advances in computer technology have led to a new generation of VR devices such as VR headsets. Accordingly, virtual reality poses many new scientific challenges for researchers and professionals.

The aim of this book, a manual meant for both designers and users of virtual reality, is to present the current state of knowledge on the use of VR headsets in the most complete way possible. The book is divided into 13 chapters. The objective of the first chapter is to give an introduction to VR and clarify its scope. The next chapter presents a theoretical approach to virtual reality through our Immersion and Interaction methodology also known as "3I² model''. Then, a chapter about human senses is necessary to understand the sensorimotor immersion, especially vision. These chapters are followed by several chapters which present the different visual interfaces and the VR headsets currently available on the market. These devices can impart comfort and health problems due to sensorimotor discrepancies. A chapter is devoted to these problems, followed by a chapter that gives a detailed discussion of methods and 32 solutions to dispel, or at least to decrease, VR sickness. The following three chapters present different VR applications that use VR headsets (behavioural sciences, industrial uses and Digital Art) and the final chapter provides conclusions and discusses future VR challenges.

Part I

A theoretical and pragmatic approach for VR headsets

Chapter 1

Introduction and challenges

Virtual reality has developed in the world over the last twenty years. It potentially opens up new perspectives for our society. But let’s be realistic – first of all, virtual reality creates many scientific challenges for researchers and professionals. Being aware of the immensity of the task at hand, we have participated enthusiastically in helping virtual reality in France blossom. For our part, we conducted theoretical and applied research on the interface of the subject (user interface) in a virtual environment. However, no researcher can ever have a precise, essentially interdisciplinary knowledge of all the sectors of virtual reality. We wanted other French researchers, Pascal Guitton and Guillaume Moreau, to participate in writing the book “Virtual Reality: Concepts and Technologies”, publisher CRC Press, originally published in French as: “Le Traité de la Réalité Virtuelle”, with 101 authors, five volumes, publisher “Les Presses des Mines”.

Thanks to technological developments, man has been able to satisfy this need through various but set representations of the world that are mainly audio or visual. Set in the sense that the user can observe the representation only as a spectator, be it a painting, a photograph, or a film of real or computer-generated images. Virtual reality offers him an additional dimension by providing him a virtual environment in which he becomes the actor. The readers must not be mistaken; the novelty is not in the creation of virtual environments that are increasingly efficient in terms of their representation, but rather in the possibility of being able to “act virtually” in an artificial world (or “interact” in a more technical sense). Imagining virtual reality has been possible only recently, thanks to a significant increase in the intrinsic power of computers, especially the possibility of creating computer-generated images in real time and enabling a real-time interaction between the user and the virtual world.

And 2016 is the year of virtual reality in the field of general public applications: the new VR headsets (or Head Mounted Display – HMD) are sold for the general public with a low cost price. The reader must note that it is these technical developments that have permitted the new boom of virtual reality. The technology is more affordable and more accessible now. In November 2015, I decided to write a new French book about the use of this new visual interface: VR headset, originally published in French as: “Les casques de réalité virtuelle et de jeux vidéo”, publisher “Les Presses des Mines”, May 2016.

The user will no longer experience virtual worlds on simple screens, but through VR headsets offering new possibilities of visual immersion, the advantages and limitations of which are the primary concern of the present work. This does not mean that industries interested in using VR within their sectors should automatically choose VR headsets when other more suitable visual interfaces exist. This question too will be addressed here.

Though the term “virtual reality” generally refers to professional applications built around interactive environments, VR researchers and manufacturers are well aware that the same concepts and core technologies, whether hardware or software, are used in the video game industry. Examples of this abound, with such VR software as Vir-tools and Unity, developed primarily for video games, being used for professional VR applications, both in the past, in the case of Virtools, and the present, in that of Unity. As for hardware, Microsoft’s input motion control device for Xbox 360 consoles, Kinect, was rapidly diverted from its original use to be utilised by researchers today for a whole host of non-gaming VR applications. Needless to say, such technological strides are owed solely to the enormous wealth of the video game industry, which can afford to pour huge sums of money into the development of pioneering technology. There is no need to go on about the enormous financial interests at stake—just look at the stir caused by Facebook with its purchase of Oculus!

We have been using the term “virtual reality” for more than twenty years. This term is debatable and has been questioned by some. The oxymoronic expression virtual reality was introduced in the United States by Jaron Lanier in the 1980s.

After an initial reassessment of what virtual reality actually is, we will need to address a number of issues regarding human sensorimotor response, in both the real world and in virtual environments. A particular focus will be placed on the sense of vision, given the visually invasive nature of VR applications, which directly impact both the sensory perception and the motor response of users. Furthermore, a refresher course on the five senses—which in actual fact are more than five!—will be provided for those readers who may not be overly familiar with the topic, myself included at the start of my career. This review of sensory fundamentals will be enormously helpful in understanding the problems and the solutions particular to VR headset usability. In short, to fully exploit the capabilities of VR headsets, a good knowledge of human vision is necessary.

Virtual reality holds a special position in the usual scientific scheme by coupling human sciences with engineering. This position is an advantage of the intrinsic interdisciplinary nature of this domain. However, this position is also a difficulty to overcome, on the one hand in terms of training the actors of the domain, and on the other hand in terms of recognition for this multidisciplinary foundation on the part of the various disciplines that enrich it. For example, it would be too simplistic to consider virtual reality merely as a branch of computer science. Though computers make it possible to effectively program and simulate the virtual worlds, interaction of man with these worlds is possible only through software programs and technical devices compatible with cognitive, perceptive and social processes. Conversely, better understanding and formalising of the difficulties and characteristics of cognition and interaction in the virtual worlds offers an empirical foundation to stimulate research and innovation.

In any virtual reality application, the person is immersed in and interacting with a virtual environment. He perceives, decides and acts in this environment, a process schematised in a standard “perception, decision, action” loop, which must be achieved within the technical, physiological and cognitive constraints (Figure 1.1).

Figure 1.1 The standard “perception, decision, action” loop.

Figure 1.2 Diagram showing the issues of virtual reality, based on the “perception, decision, action” loop.

Three fundamental issues of virtual reality can be deduced from this diagram (Figure 1.2):

• The issue of the analysing and modelling the human activity in real environment and in virtual environment;
• The issue of analysing, modelling and creating an interface for the subject for his immersion and interaction in a virtual environment;
• The issue of modelling and creating the virtual environment.

VR headset utilisation raises the three following questions:

– How are VR headset users affected by display latency and
sensorimotor discrepancy in virtual worlds?

– Which types of user interfaces and interactions generate the above latencies and discrepancies?

– How can various systems and computer algorithms help reduce the effects of the aforesaid artefacts?

The book is divided into two sections: “Theoretical and pragmatic approach for VR headsets” and “VR headset applications”. The chapter 2 introduction to virtual reality clarifies the book’s scope and presents the theoretical approach, also known as “3I² model”. Then, chapter 3 about human senses is necessary to understand the sensorimotor immersion, especially vision in real and virtual environments. These chapters are followed by chapter 4 which presents the different visual interfaces available, chapter 5 is about the VR headsets, chapter 6 about the user interfaces exploited with VR headsets and chapter 7 about the commercial devices available on the market (author: Olivier Hugues). These visual interfaces can imply comfort and health problems with the sensorimotor discrepancies. Chapter 8 is devoted to these problems, followed by chapter 9 that gives a detailed discussion of methods and 32 solutions to remove, or to decrease the VR sickness. Then, the “VR headset applications” second section presents different VR applications that use headsets (Behavioural Lab Experiments – author: Daniel Mestre; Industrial uses of VR headsets – author: Andras Kemeny; Creating Digital Art Installations With VR Headsets – authors: Judith Guez and Jean-François Jégo) and the last chapter gives conclusions and future VR challenges.

We can only wonder whether developers are fully aware of the enormity of the task at hand, of the obstacles that need to be overcome and the laws that need to be complied with for designing effective VR applications. Moreover, if these issues are indeed resolved, can we be certain that users will be able to successfully adapt to visual immersion? The main purpose of this work is to present a general review of such questions, keeping in mind that VR technologies “perturb” our physiological and sensorimotor response. This can be likened to the sensorimotor discrepancy created by the accommodation/vergence conflict of stereoscopic vision. However, professionals in the field, or stereographers, have long been aware of the rules governing stereoscopic image making (3D). The first of these, dating back more than 150 years, was determined by David Brewster in 1856, and many experiments have since been conducted to establish the types of imagery that viewers are comfortable with. As for VR headsets, the latest of these visually intrusive interfaces, user feedback is still very limited. We can only hope that the experts will address this question to which very little attention has been paid to date. In part to protect themselves from this lack of scientific data, some VR headset designers warn of the potential risks linked to their products and have set a minimum user age. At first glance, these issues seem far more complex than those of stereoscopic vision, from a purely intuitive perspective at any rate. Furthermore, since VR headsets are not yet used by the general public, researchers lack data from large target group studies. The fact is, it remains to be seen how well we will adapt to visual immersion in virtual worlds; some people may be more sensitive than others yet without really knowing why. Another issue raised by VR headset use is whether the risk of video game addiction will be greater for gamers wearing VR headsets than for those interacting via a simple screen. This question, which is a matter for psychologists and psychiatrists, will not be discussed here, though, to my knowledge, no serious research has been conducted on the subject to date.

Though the effects of VR headset use raise special problems of comfort and health, they also afford exciting possibilities, as virtuality allows us to go beyond the limits of reality. Questions of physical perception, of experiencing “presence” in a space in which we are either unable, or only partially able, to see our own body (our avatar’s hands) must also be answered. How do we respond to seeing ourselves visually but in another body, to what could be qualified as an out-of-body experience? All of these behavioural questions, as well as our capaci...