An Algorithm for Real-Time Fast Walkthrough of Massive Terrain

Terrain walkthrough is a hot point in GIS, virtual reality and military simulation fields. Large scale terrain algorithm is used to load data partly into the memory, and then simplify terrain to speed up drawing-rate. This paper presents an algorithm which blocks the terrain, uses back face culling and modified viewpoint error equation to construct Level of Detail (LOD), and then uses a new horizon culling method based on screen error bounding box. This algorithm has a fast drawing-rate. Besides, memory mapping file technique to load DEM data is used to make the algorithm have high performance data process ability on massive terrain data.