Research And Construct Of Three Dimension Virtual Terrain Based On OpenGL Technology

This paper makes the survey to visualization technology quickly and really of three-dimensional Virtual Terrain model to create triangle grid of terrain on the basis of consultingrelevant documents.It is mainly surface by using DEM(Digital Elevation Model).Thetechnology of geographic information system (GIS), geographic information visualization, andthree-dimensional (3D) display, spatial data processing as well as object oriented modularprogramming method etc. are the precondition and key to study three-dimensionalvisualization cruise system. This paper talked about the principle and key technology ofvisualization, the theory of third dimension terrain drawing and Digital Elevation Model (DEM)construction, the technology of 3D terrain display in real-time etc., and introduced thetechnology of 3D graph display using OpenGL that adopted to develop a program.In GIS, Terrain Visualization help to understand the interrelation of spatial data and theresult of analysis. Terrain visualization is important content of GIS, and is the majortechnology to establish the Digital Earth.In this paper, the fundamental theory and methods of terrain modeling, include regularsquare grid and triangulated irregular network, is studied. Then, terrain simplification andmultiresolution model is discussed, and comprehensively summarize the previouswork. Based on the analysis of OpenGL, study on the terrain visualization. And basic terrainanalysis is solved. Besides,the paper do also much work about enhancing the Real-timephotorealistic terrain and shadow effect etc. At the same time,process simple analysis for DEMaccuracy in practical application.The experimentation make know, the method is feasible,attainthe stated of mutual control of VE(Virtual Environment).But,it is also faultiness on someaspects,which is the emphases of us in the future.Finally based on the theoretic research accomplishment of this paper, for example asJingouling forest the author developed a 3D Virtual Terrain system using OpenGL technologyin Visual C++ development environment. Functions of this system are as follows: data importand reconstruction, digital model simplification export, 3D digital model and texture paste, flyroute display setting flight simulation coast, which offers a kind of new means for the researchof Forest map.