Research On Technologies Of 3D Terrian Visualization Basing On OpenGL

The visualization of three-dimensional terrain can be used to reveal the information and synthetical character of 3D terrain directly and really. It is widely used in many fields. And it has broad practical foreground. Based on lots of advanced results of computer graphics, computer science, GIS etc. this thesis discussed the related theory, techniques and arithmetic of three-dimensional terrain visualization implementation based on OpenGL detailedly including the basic theory of three-dimensional visualization and three-dimensional terrain visualization, three-dimensional geometry sculpting techniques, the means of curved surface fitting of discrete data, the principle and the related techniques of OpenGL, the main style of DEM, several main difference methods of discrete data gridding, the improved arithmetic of discrete data gridding, three-dimensional terrain modeling techniques, the implementation theory of the third dimension graphics, the query techniques of three-dimensional coordinates and the interaction of person and computer.Based on the researched result of the above theory, I put forword an improved algorithm in making discrete data to be gridded, and set up a system framework, which can be used to develop three-dimensional terrain visualization. The three-dimensional visualization real time browse system using OpenGL has been established based on Windows XP system and Visual C++ 6.0. The system can receive and pretreat the discrete data of DEM format, realize different pattern three-dimensional visualization of line, different color and texture, etc. and has the functions of real time dynamical browse, three-dimensional coordinates query, grid data and three-dimensional figure export etc.This investigation has important theoretic and practical meaning. In theory, the improved algorithm of discrete gridding, three-dimensional terrain model, and three-dimensional coordinates query technology about three-dimensional terrain visualization are investigated. In practice, a digital, visible and intelligentized three-dimensional terrain visualization dynamical browse system is builded, providing a scientific, valid, easy and direct way for visualization analysis.