1.2. Virtual Reality

What has been described here is a vision of an interaction in what would be commonly called "Virtual Reality". Because this term has been the subject of so much imagination, speculation, consideration, and empty hype, we endeavor to explain here our vision of what Virtual Reality (VR) means, and how we think it can be realized.

Some would define VR quite broadly: VR is the use of computer networks to realize a shared dream world, a world whose rules are not those of real life. Unlike storytelling, the creation of a world in the minds of a passive audience, each participant of this shared dream world is an actor, free to do as they like upon the virtual stage. This notion of VR applies to nearly any computer-mediated exchange where the setting or premise is detached from the real world. This includes the huge market of online games, MUDs, MUSHs, MOOs and their brethren, and sometimes interactive chat systems such as IRC. The only qualifications seem to be that a system be interactive (as opposed to the slow, asynchronous nature of email, usenet or the world wide web) and involve some suspension of disbelief.

Another definition of VR takes the term more literally. VR is the technology which allows one to fool the user's senses into believing they are in another place, actively experiencing a different reality. This is accomplished through stereoscopic headsets and stereophonic headphones, tactile or haptic displays, and the synchronization of the user's physical movements to changes in the sensations created with such devices. Like the previous definition of VR, the crux of the idea is interactivity and suspension of disbelief. But here the emphasis is on graphical and other presentation aspects rather than as a new medium for exchange.

Somewhere between the two extremes of imaginary reality and illusory reality is a definition which reflects the most commonly held notion of virtual reality. We propose the following definition which we will use for the remainder of this discussion: Virtual Reality is a persistent three-dimensional space fundamentally designed to use computer networks for communications among many users. Users are represented by articulated three-dimensional models called avatars and interact with each other in real time for social, entertainment, educational and economic purposes; users are able to contribute to the world by creating, modifying, deleting or otherwise interacting with any feature of the world for which they have permission to do so. Users can even use VR as a medium for interacting with representations of abstract data and with autonomous software agents.

Many systems satisfy some criteria of this definition. Online games allow for realtime interaction in three dimensions, but do not enable the user to contribute to the world in a unique or substantive way. Some MUDs, MUSHes and MOOs give great freedom to the users to interact with and add to the world, but these systems are limited to text-based communication. Finally, some technologies like VRML address only the problems of 3D visualization, and completely ignore the interactive aspects of VR.

VR systems which fulfill all of these requirements do exist, which raises the question of why they have not become popular. The answer, as far as we have been able to tell, is that all attempts at building general-purpose VR for the Internet have been either laboratory prototypes or overly commercialized. Furthermore, capable graphics rendering hardware has only recently become available to the average consumer. Prototypes often lack ongoing development and are eventually discarded due to limited functionality or outdated technology. Commercial systems are doomed to being relevant only so long as they make money for their creators and are closed to outside development. As a result, the dream of an open, shared, interactive cyberspace continue to elude us.