An Author-friendly Concept for Multi-User Virtual Environments in VRML

One of the visions often associated with the Virtual Reality Modeling Language (VRML) is that of a giant networked 3-dimensional "cyberspace" in which people can meet and interact. Yet, despite the astonishingly rapid development of VRML, which recently has become ISO standard, so far multi-user interaction in VRML-based environments has not become commonplace. In this paper we want to put emphasis on a very important aspect in multi-user systems: Distributed applications are inherently more complex than usual, single-user applications. This complexity is often passed on to the scene author. The Multi-User System Concept (MUSyC) introduced in this paper is a new approach towards providing simple, portable, and efficient multi-user interaction in VRML. Our prototype builds entirely upon the VRML 97 standard with no proprietary extensions, is written in Java for platform independence, and has been designed specifically with the world author in mind, who is usually not a distributed syste ms expert. In the following, we will present the concept and how it uses certain features of VRML. Finally, the authoring process of a shared world is discussed.