Triangulated Irregular Network And Its Visualization Implementation

The Triangular Irregular Network(TIN) is regarded as the most basic and important model in DEM. it can describe the surface topography in terms of different levels of resdution. It can deal with special terrain flexibly. This thesis mostly researches on the algorithm of constructing Triangulation and reconstructing Triangulation, the algorithm of constructing and disposing contours based on TIN, and the algorithm of visualization based on TIN, which are the important research fields in GIS.The algorithm of constructing TIN is designed and implemented, then the traditional methods of constructing contour based on TIN are amended, that is, the all data-structure of the algorithm are designed, including array of equivalent-point and borders and point-borders and so on. the equivalent points and topological relations are made to reconstruct TIN, which is much finer than the original TIN in visualization.Finally, taking the image and intuitive TIN and the difficulties of TIN data analysis into consideration, the thesis designes and implements a algorithm of hill-shading with OpenGL and VC++.NET. in the case of poor precision ,the algorithm is somewhat practical.