DWTP — An Internet Protocol For Shared Virtual Environments Wolfgang

Permission to make digital/hard copies of all or part of this material for personal or classroom use is granted witohout fee provided that the copies are not made or distributed for profit or commercial advantage, the copyright notice, the title of the publication and its date appear, and notice is given that copyright is by permission of the ACM, Inc. To copy other wise, to republish, to post on servers or to redistribute to lists, requires specific permission and/or fee. Abstract VRML (the Virtual Reality Modeling Language) has brought 3D objects and virtual worlds to a large number of Internet users. While it provides a suitable basis for the platform independent description of virtual worlds, an appropriate network architecture required to realize shared virtual worlds on the Internet is still an open issue. In this paper we will introduce DWTP (the Distributed Worlds Transfer and communication Protocol). DWTP is an application layer protocol for shared virtual environments on the Internet. It provides a scalable network architecture for large-scale distributed virtual worlds. 1 INTRODUCTION Research on distributed virtual environments has been stretched out for several years with remarkable success on various aspects of it [8] [15]. Most systems realized did not achieve a large spread however, since they were limited to certain platforms or specific networks. VRML—the Virtual Reality Modeling Lan-guage— gives us for the first time the opportunity to develop large scale virtual worlds inhabited by worldwide distributed participants independent of a specific platform or operating system. The current VRML standard [1] however, does not provide any support for sharing VRML worlds with other users. While a number of approaches have been made to extend VRML in order to support multiple users [12], their representation by avatars as well as the sharing of objects [9], most of them rely on simple network architectures based on central servers [6]. An appropriate scalable network protocol for large distributed virtual environments on the Internet is still an open issue. More recent proposals for new network protocols or architec-tures such as VRTP [5] and ISTP [2] indicate, that a flexible, scalable and universal network protocol for shared virtual worlds will be based on a heterogeneous approach including several basic internet protocols rather than using a single distribution scheme. In this paper we will present our approach of an application independent network protocol for shared virtual environments. Our approach was guided by the following considerations: …