Research and Realization on 3D GIS Visualization system based on OpenGL

In this paper, we discuss the theory, technology and algorithms of three-dimensional (3D) GIS visualization; it includes terrain surface modeling techniques of digital elevation model (DEM), basic theory of three-dimensional (3D) terrain visualization, Triangular Irregular Network (TIN) type and algorithms, dynamic three-dimensional terrain display techniques based on simplified model, and spatial searching techniques based on three-dimensional terrain map. OpenGL graphic function library is The most widely used industry standards in the world, we analysis its interface and function, design and construct the module based on that. In the end, we demonstrate the theory with a system that can display the 3d terrain we need.