RING: a client-server system for multi-user virtual environments

ABSTRACT

This paper describes the client-server design, implementation and experimental results for a system that supports real-time visual interaction between a large number of users in a shared 3D virtual environment. The key feature of the system is that server-based visibility algorithms compute potential visual interactions between entities representing users in order to reduce the number of messages required to maintain consistent state among many workstations distributed across a wide-area network. When an entity changes state, update messages are sent only to workstations with entities that can potentially perceive the change—i.e., ones to which the update is visible. Initial experiments show a 40x decrease in the number of messages processed by client workstations during tests with 1024 entities interacting in a large densely occluded virtual environment.

REFERENCES

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INDEX TERMS

Primary Classification:
  C. Computer Systems Organization
  C.2 COMPUTER-COMMUNICATION NETWORKS
      C.2.1 Network Architecture and Design
          Subjects: Network topology

Additional Classification:
  H. Information Systems
  H.5 INFORMATION INTERFACES AND PRESENTATION (I.7)
      H.5.3 Group and Organization Interfaces
          Subjects: Synchronous interaction

  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.3 Picture/Image Generation
          Subjects: Viewing algorithms
      I.3.7 Three-Dimensional Graphics and Realism
          Subjects: Virtual reality

General Terms:
Algorithms, Design, Experimentation

Keywords:
3D virtual environments, client-server design, distributed systems, multi-user systems, real-time graphics, virtual reality, visual simulation