Recently, with the continuing development of the computer software, computer hardware and communication, the restriction in geographical process caused by static, two dimension and digital is eliminated by new technology of GIS. The former GIS become interactive visualization which is dynamic analysis, dynamic simulation. Lots of spatial data are multi dimension and multi source is processed and analyzed. Visual simulation is foundation of dynamic, multi dimension and interactive system .It is a hotspot in the research of geographic information system.Terrain modeling techniques for digital elevation model, process of vision and technology of visualization dynamical real-time display are main contents in visualization. The GIS visual simulation makes use of lots of relative arithmetic and methods in visualization. The following main content:1 Using Constrained Delaunay Triangulation create terrain skin; 2 Using arithmetic of adding power average compute contour value; 3 Using arithmetic of relation viewpoint predigest polygons. 4 Using model of instantaneous marine create 3D models. Furthermore, this system realizes multi computer co-simulation running by the protocol of communication and control and technology of socket. ActiveX object models design implement upgrading conventional simulation system compatible with HLA and promotes reusability. The GIS visual simulation has already utilized in project successfully. |