A Visibility Judge Algorithm for Message Communication in Distributed 3D GIS Environment

Distributed 3D GIS was a multi-user system. In the system, concurrent accessing and interactive operation always require good response and high performance. User in the virtual environment should be able to obtain status changing of others and communicate among them. How to coordinate users and supply an efficient interactive method was the key problem in the distributed virtual 3D GIS. In this paper, after the analysis of the existing systems, we presented a system framework based on distributed technology, designed a multi-user communication and message mechanism, and developed a message filtering algorithm based on visibility judge.