Designing Virtual Reality Systems: The Structured Approach

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  • Gerard Jounghyun Kim

    Designing Virtual Reality Systems

    The Structured Approach

    With 191 Figures

  • Gerard Jounghyun Kim, BS, MS, PhDDepartment of Computer Science and EngineeringPohang University of Science and Technology (POSTECH)Korea

    British Library Cataloguing in Publication DataA catalogue record for this book is available from the British Library

    Library of Congress Control Number: 2005923778

    ISBN-10: 1-85233-958-6 Printed on acid-free paperISBN-13: 987-1-85233-958-6

    Springer-Verlag London Limited 2005Apart from any fair dealing for the purposes of research or private study, or criticism or review,as permitted under the Copyright, Designs and Patents Act 1988, this publication may only bereproduced, stored or transmitted, in any form or by any means, with the prior permission inwriting of the publishers, or in the case of reprographic reproduction in accordance with theterms of licences issued by the Copyright Licensing Agency. Enquiries concerning reproductionoutside those terms should be sent to the publishers.The use of registered names, trademarks etc. in this publication does not imply, even in theabsence of a specific statement, that such names are exempt from the relevant laws andregulations and therefore free for general use.The publisher makes no representation, express or implied, with regard to the accuracy of theinformation contained in this book and cannot accept any legal responsibility or liability for anyerrors or omissions that may be made.Whilst we have made considerable efforts to contact all holders of copyright material containedin this bok, we may have failed to locate some of them. Should holders wish to contact thePublisher, we will be happy to come to some arrangement with them.

    Printed in the United States of America. (SPI/EB)

    9 8 7 6 5 4 3 2 1

    Springer ScienceBusiness Mediaspringeronline.com

  • To

    Dad, who has been my inspiration,

    Mom, for her unconditional love,

    and God for his grace.

  • Contents

    Section I: Basics of Designing Virtual Reality Systems . . . . . . . . . . . . . . . . . 1

    . Chapter 1. Introduction: Virtual Reality in a Nutshell . . . . . . . . . . . . . . . 3& What Is Virtual Reality? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3& Goals and Applications of Virtual Reality . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3& Two Pillars of VR: Presence and 3D Multimodal Interaction . . . . . . . . 5& Building a Virtual Reality System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8& About This Book. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10& Final Notes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11& Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

    . Chapter 2. Requirements Engineering and Storyboarding. . . . . . . . . . . . 14& Example: Ship Simulator Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26

    . Chapter 3. Object and Scene Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . 27& Object Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27& Scene Construction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36& Object Placement . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36& Multiple Frames of Reference . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 42& Re-Expressing Coordinates . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43& Function and Behavior Modeling. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47& Ship Simulator Example Revisited. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50

    . Chapter 4. Putting It All Together . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53& Example Continued: Ship Simulator, Level 2 Design . . . . . . . . . . . . . . . . 56& Summarry and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65

    vii

  • . Chapter 5. Performance Estimation and System Tuning . . . . . . . . . . . . 66& Tuning with LOD Models. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 66& Presence/Special Effects . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67& Using Images and Textures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68& Summary and Pondering Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73

    Section II: Creating the Virtual Reality . . . . . . . . . . . . . . . . . . . . . . . . . . . . 75

    . Chapter 6. Output Display. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77& The Human Visual System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77& Human Depth Perception and Stereoscopy . . . . . . . . . . . . . . . . . . . . . . . . . . 81& Visual Display Systems . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 88& Human Aural System. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98& Aural Display Systems. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 103& Haptics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105& Stimulation of Other Modalities I. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108& Summary and Pondering Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 113

    . Chapter 7. Sensors and Input Processing . . . . . . . . . . . . . . . . . . . . . . . . 115& Trackers. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 116& Event Generators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 118& Sensor Errors and Calibration . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120& Summary and Pondering Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 121

    . Chapter 8. 3D Multimodal Interaction Design. . . . . . . . . . . . . . . . . . . . 122& Why Go 3D Multimodal? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 122& Structured Approach to Interaction/Interface Design . . . . . . . . . . . . . . 123& Metaphors . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 125& Interface Design . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 126& Multimodality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 128& Case Studies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

    ^ Ship Simulator . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 130

    ^ Immersive Authoring . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 131

    ^ Tabletop Computing. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 134

    ^ Selection and Manipulation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 137

    ^ Navigation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 142

    ^ Menu Selection and Invocation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 143

    ^ Whole Body Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 147

    ^ Tangible Interface . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 148

    ^ Alphanumeric Input . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 150& Summary and Pondering Points. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 152

    . Chapter 9. Simulation I: Collision Detection . . . . . . . . . . . . . . . . . . . . . 153& Handling Collision. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 153

    viii Contents

  • & Collision Detection with Line Segment(s) . . . . . . . . . . . . . . . . . . . . . . . . . . 155& Collision Among Polygonal Models . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 160& Bounding Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 166& Building a Bounding Volume . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 169& Bounding a Volume Hierarchy. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 172& Collision Among Bounding Volumes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 173& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 178

    . Chapter 10. Simulation II: Physics-Based Motionand Collision Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 179& Center of Gravity and Moment of Inertia . . . . . . . . . . . . . . . . . . . . . . . . . . 179& Linear and Rotational Kinematics. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 185& Laws of Motion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 187& Dynamics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 191& Ad Hoc Collision Response. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192& Physics-Based Collision Response . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 192& Real-Time Simulation Renisited . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 195& Deformation. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 196& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 197

    . Chapter 11. Virtual Characters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199& Form of a Character . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 199& Motion Control . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 200& Forward Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 206& Inverse Kinematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 210& Summary and Pondering Points . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 213

    . Epilogue . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215& Other Areas of Virtual Reality. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 215& Is Virtual Reality Really Any Good? . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216& Virtual Reality for Spatial Presence. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 216

    References . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 219

    Index . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 227

    Contents ix

  • Section I

    Basics of Designing VirtualReality Systems

  • Chapter 1

    Introduction: VR in a Nutshell

    What Is VR?

    Virtual Reality (VR)1 is a field of study that aims to create a system that

    provides a synthetic experience for its user(s). The experience is dubbed

    synthetic, illusory, or virtual because the sensory stimulation to the

    user is simulated and generated by the system. For all practical purposes,

    the system usually consists of various types of displays2 for delivering the

    stimulation, sensors to detect user actions, and a computer that processes the

    user action and generates the display output. To simulate and generate

    virtual experiences, developers often build a computer model, also known

    as virtual worlds or virtual environments (VE) which are, for instance,

    spatially organized computational objects (aptly called the virtual objects),

    presented to the user through various sensory display systems such as the

    monitor, sound speakers, and force feedback devices.

    One important component of a successful VR system is the provision of

    interaction, to allow the user not just to feel a certain sensation, but also to

    change and affect the virtual world in some way. Figure 1.1 captures the

    basic architecture of a VR system and various associated terminologies.

    Goals and Applications of VR

    Of, what value is a virtual experience? Obviously, it allows people to get the

    experience of things that would otherwise be very difficult or even impossible

    to attain in real life, like going to the South Pole or to the Moon. The virtual

    experience can even be something imaginary and abstract (rather than real-

    life inspired), such as experiencing an abstract mathematical world or an

    1 The term VR is also used to describe the technology or medium used to createand convey the synthetic experience, or even sometimes to the experience itself.

    2 In VR literatures, the term display not only refers to the usual visual displaybut also to any sensory output device.

    3

  • imaginary world envisioned by an artist. Thus, it goes without saying that

    virtual experiences are useful for many purposes including training, educa-

    tion, and entertainment.

    One of the sources of confusion regarding the concept of VR is whether or

    how it is different from the 3D (networked) PC/console games or similarly

    from the terms like cyberworld, web-based chatting, etc.. Broadly speak-

    ing, 3D games are one type of VR system in the sense that they provide a

    virtual experience of some sort. However, most 3D games, for commercial

    reasons, are still keyboard-mouse-based or based on simp...

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