A Client-Server-Scenegraph for the Visualization of Large and Dynamic 3D Scenes

With the increasing capabilities of hardware for 3D graphics and network, 3D multi-user environments get more and more interesting for e-business, entertainment and cooperative work. This aspect concerns not only high-end devices, like caves or graphic workstation, also small mobile devices like laptop computers or PDAs become more and more suitable for the visualization of 3D graphics. In order to visualize a large and dynamic 3D scene on multiple clients with different capabilities, an appropriate scene representation is required. In this paper a client-server-scenegraph is introduced, which addresses critical problems in the area of distributed 3D graphics such as the handling of dynamic 3D scenes, which exceed the capacity of the clients or even of the server. Another point is the selection of the data, which has to be transmitted from the server to the clients, although the users and the scene elements are moving. Since many clients lack the memory, they only hold the currently most relevant scene information. For that reason there has to be an efficient matching between the server's and the clients' data