Abstract:

In order to achieve fast and highprecision rendering of mass data for three-dimensional terrain visualization,this article analyzes two main DEM
（Digital Elevation Models）including TIN（Triangulated Irregular Network） and GRID for creating 3D terrains.Through analyzing the sample points' traits of the
 two models,disadvantage and data structures,a hybrid method for building DEM has been proposed.We discuss the steps of creating mixed model,including calculation terrain complexity,creation data structure of mixed model and building TIN.The hybrid method was tested by the actual experiments which shows good performance for three-dimensional terrain visualization.

Key words: digital elevation models（DEM）, triangulated irregular network（TIN）, GRID, 3D terrain, visualization, hybrid model