With the geographic information system (GIS) development, digital terrain model (DTM) has been used widely in GIS applications, DTM has become an integral part of GIS, it is the digital elevation model(DEM) and features in integration. It is not only as a basic data, but also as an application method, geology, construction and military fields play an increasingly important role.This paper systematically expound the rapid establishment of a virtual scene terrain model theory and method, analysis and compare the terrain model, compared with the method to establish several commonly used method of construction of TIN, analyzes their advantages and disadvantages. This article uses the zoning laws and the Combination of Fast Convex Hull method, optimizing the data using contour lines to build triangulated irregular network (TIN) modeling method is fast building a triangular nets TIN modeling. Topographic features of the model, taking into account the impact of the quality, the choice of interpolation method of characteristic line to complete the construction based on the topographic features of the TIN. The use of a triangle with the characteristics of the relationship between the edge and the TIN topology, rapid elimination of flat triangles, improve the quality of TIN, the main research grid from the TIN to DEM conversion algorithm, a fast conversion methods to improve the conversion efficiency, especially for The DEM data in the massive building. At the same time, this article also studied the terrain visualization, terrain LOD techniques, the feature fusion method, and an example is analyzed. Concluded paper and put forward. |