Understanding Virtual Reality arrives at a time when the technologies behind virtual reality have advanced to the point that it is possible to develop and deploy meaningful, productive virtual reality applications. The aim of this thorough, accessible exploration is to help you take advantage of this moment, equipping you with the understanding needed to identify and prepare for ways VR can be used in your field, whatever your field may be.


By approaching VR as a communications medium, the authors have created a resource that will remain relevant even as the underlying technologies evolve. You get a history of VR, along with a good look at systems currently in use. However, the focus remains squarely on the application of VR and the many issues that arise in the application design and implementation, including hardware requirements, system integration, interaction techniques, and usability. This book also counters both exaggerated claims for VR and the view that would reduce it to entertainment, citing dozens of real-world examples from many different fields and presenting (in a series of appendices) four in-depth application case studies.

* Substantive, illuminating coverage designed for technical and business readers and well-suited to the classroom.
* Examines VR's constituent technologies, drawn from visualization, representation, graphics, human-computer interaction, and other fields, and explains how they are being united in cohesive VR systems.
* Via a companion Web site, provides additional case studies, tutorials, instructional materials, and a link to an open-source VR programming system.

Table of Contents

Foreword 
Preface

Part I - What is Virtual Reality?
Chapter 1: Introduction to Virtual Reality - What it is and Where it Comes From
Chapter 2: VR the Medium

Part II - Virtual Reality Systems 
Chapter 3: Interface to the Virtual World -- Input 
Chapter 4: Interface to the Virtual World -- Output 
Chapter 5: Rendering a Virtual World 
Chapter 6: Interacting with a Virtual World 
Chapter 7: Virtual Reality Experience 
Chapter 8: Experience Design: Applying VR to a Problem
Chapter 9: What Dreams May Come: The Future of VR 

Appendices
A: NICE educational application (EVL) 
B: Crumbs visualization application (NCSA)
C: Aircraft wiring application (Boeing, Inc.) 
D: Placeholder artistic application (Interval Research)

Understanding Virtual Reality: Interface, Application, and Design

The Go-Go immersive interaction technique uses the metaphor of interactively growing the user’s arm and non-linear mapping for reaching and manipulating distant objects. Unlike others, our technique allows for seamless direct manipulation of both nearby objects and those at a distance.

http://www.ivanpoupyrev.com/e-library/1998_1996/uist96.pdf

The go-go interaction technique: non-linear mapping for direct manipulation in VR

Grabbing and manipulating virtual objects is an important user interaction for immersive virtual environments. We present implementations and discussion of six techniques which allow manipulation of remote objects. A user study of these techniques was performed which revealed their characteristics and deficiencies, and led to the development of a new class of techniques. These hybrid techniques provide distinct advantages in terms of ease of use and efficiency because they consider the tasks of grabbing and manipulation separately. CR Categories and Subject Descriptors: 1.3.7 [Computer Graphics] :Three-Dimensional Graphics and Realism - Virtual Reality; 1.3.6 [Computer Graphics]:Methodology and Techniques - Interaction Techniques.

/pdf/an-evaluation-of-techniques-for-grabbing-and-manipulating-2no8ya0jpd.pdf

An evaluation of techniques for grabbing and manipulating remote objects in immersive virtual environments

Manipulation in immersive virtual environments is difficult partly because users must do without the haptic contact with real objects they rely on in the real world to orient themselves and their manipulanda. To compensate for this lack, we propose exploiting the one real object every user has in a virtual environment, his body. We present a unified framework for virtual-environment interaction based on proprioception, a person's sense of the position and orientation of his body and limbs. We describe three forms of body-relative interaction: • Direct manipulation—ways to use body sense to help control manipulation • Physical mnemonics—ways to store/recall information relative to the body • Gestural actions—ways to use body-relative actions to issue commands Automatic scaling is a way to bring objects instantly within reach so that users can manipulate them using proprioceptive cues. Several novel virtual interaction techniques based upon automatic scaling and our proposed framework of proprioception allow a user to interact with a virtual world intuitively, efficiently, precisely, and lazily. We report the results of both informal user trials and formal user studies of the usability of the body-relative interaction techniques presented. CR

/pdf/moving-objects-in-space-exploiting-proprioception-in-virtual-44v79fnu5r.pdf

Moving objects in space: exploiting proprioception in virtual-environment interaction

This paper describes a new measure for presence in immersive virtual environments (VEs) that is based on data that can be unobtrusively obtained during the course of a VE experience. At different times during an experience, a participant will occasionally switch between interpreting the totality of sensory inputs as forming the VE or the real world. The number of transitions from virtual to real is counted, and, using some simplifying assumptions, a probabilistic Markov chain model can be constructed to model these transitions. This model can be used to estimate the equilibrium probability of being “present” in the VE. This technique was applied in the context of an experiment to assess the relationship between presence and body movement in an immersive VE. The movement was that required by subjects to reach out and touch successive pieces on a three-dimensional chess board. The experiment included twenty subjects, ten of whom had to reach out to touch the chess pieces (the active group) and ten of whom only had to click a handheld mouse button (the control group). The results revealed a significant positive association in the active group between body movement and presence. The results lend support to interaction paradigms that are based on maximizing the match between sensory data and proprioception.

/pdf/a-virtual-presence-counter-2a81rmpuh2.pdf

A Virtual Presence Counter

Virtual environments have shown considerable promise as a natural (and thus it is hoped more effective) form of human-computer interaction. In a virtual world you can use your eyes, ears, and hands much as you do in the real world: move your head to set your viewpoint, listen to sounds that have direction, reach out your hands to grab and manipulate virtual objects. Virtual worlds technologies (such as head-tracking and stereo, head-mounted displays) provide a better understanding of three-dimensional shapes and spaces through perceptual phenomena such as head-motion parallax, the kinetic depth effect, and stereopsis. Precise interaction, however, is difficult in a virtual world. Virtual environments suffer from a lack of haptic feedback (which helps us to control our interaction in the real world) and current alphanumeric input techniques for the virtual world (which we use for precise interaction in the computer world) are ineffective. We are unfamiliar with this new medium we work in; we do not fully understand how to immerse a user within an application. Before we can create virtual world solutions to real world problems we must learn how to interact with information and controls distributed about a user instead of concentrated in a window in front of him. We must identify natural forms of interaction and extend them in ways not possible in the real world.

/pdf/virtual-environment-interaction-techniques-1gctclt85j.pdf

Virtual Environment Interaction Techniques

This paper presents a set of interaction techniques for use in headtracked immersive virtual environments. With these techniques, the user interacts with the 2D projections that 3D objects in the scene make on his image plane. The desktop analog is the use of a mouse to interact with objects in a 3D scene based on their projections on the monitor screen. Participants in an immersive environment can use the techniques we discuss for object selection, object manipulation, and user navigation in virtual environments. CR Categories and Subject Descriptors: 1.3.6 [Computer Graphics]: Methodology and Techniques - InteractionTechniques; 1.3.7 [Computer Graphics]: Three-Dimensional Graphics and Realism - VirtualReality. Additional Keywords: virtual worlds, virtual environments, navigation, selection, manipulation.

/pdf/image-plane-interaction-techniques-in-3d-immersive-2hvs0i3joc.pdf

Image plane interaction techniques in 3D immersive environments

Disney's VR Studio developed Panda3D, a graphics engine and programming environment, to be flexible enough to support everything from real-time graphics applications to the development of high-end virtual reality theme park attractions or video games. The acronym itself lists Panda's primary features as platform-agnostic, networked, display architecture. As a result of its powerful and flexible design, much of the Panda system's architecture reflects the occasionally opposing goals of performance and versatility.

The Panda3D graphics engine

This paper presents a description of ISAAC, the Immersive Simulation Animation And Construction program designed and built at the University of North Carolina at Chapel Hill (UNC-CH). ISAAC is a scene composition application for the interactive construction of virtual worlds. Working directly in a virtual environment, objects can be positioned, oriented and scaled using direct and indirect manipulation techniques. Object configurations are stored in ASCII files which can be used to recreate object configurations at a later date for further manipulation and interactive exploration. ISAAC is not a modeling program, worlds are created by manipulating pre-generated three-dimensional models (which can come from sources such as Computer-Aided Design programs or three-dimensional scanning devices). ISAAC has been designed to overcome some of the limitations of working in a virtual environment and to take advantage of the natural and intuitive forms of interaction available in a virtual world.

https://www.cs.unc.edu/techreports/95-020.pdf

Mark R. Mine

Papers

Moving objects in space: exploiting proprioception in virtual-environment interaction

Virtual Environment Interaction Techniques

Image plane interaction techniques in 3D immersive environments

The Panda3D graphics engine

ISAAC: A Virtual Environment Tool for the Interactive Construction of Virtual Worlds