GIS Park

The three-dimensional model is the basic element of the virtual geographical scene. The research of modeling technology has been following the whole course of the visual technical development of the virtual geographical scene all the time. This paper makes deeper research and discussion to virtual geographical scene theory and method of modeling, and research respectively on the construction of several different kinds of space data models based on VRML language.(1) This paper studies to terrain modeling with VRML as the developing language, and builds the three-dimension terrain model in two kinds of organizations ways which are GRID and TIN of DEM separately, and research to terrain texture mapping. It advances a algorithm of VRML of simplify terrain data.(2) This paper discusses the method of CSG modeling. Building CSG modeling is built by VRML, the texture mapping of the building model is advanced in reason.(3) The paper realizes three-dimensional trees modeling of Billboard, Doubleboarding and L-System based on VRML. Billboard and Doubleboarding are applicable to the display of the extensive trees scene, and improve the speed of display. L-system trees model is lifelike, nature.At last, the paper summarizes conclusion of research, put forward the content further studying.