Abstract: Terrain walkthrough is a hot point in GIS, virtual reality and military simulation fields. large Large scale terrain algorithm is used to load data partly into the memory, then simplify terrain to speed up drawing-rate. This paper presents an algorithm which blocks the terrain, and uses back culling and modifieds deviation equation to construct lLevel oOf dDetail(LOD), and then uses a new horizon culled method based on screen-deviation 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.

Key words: terrain walkthrough, Continuous Level Oof Detail(LOD), view-dependent deviation, bounding box, horizon culling, memory mapping

摘要： 高性能地形漫游是GIS、虚拟现实及军事模拟中的研究热点。大规模地形算法一般都是通过将部分数据常驻内存，并采取各种方法来简化地形、，加速绘制。该文通过对地形分块，使用背面剔除及改进的视点误差来进行LOD细节层次处理；。提出基于屏幕误差包围盒的地平线遮挡剔除技术，提高算法的效率；。采用内存映射文件方式进行DEM数据的加载，实现高性能海量数据的处理。

关键词: 地形漫游, 细节LOD层次细节, 视点误差, 包围盒, 地平线剔除, 内存映射

CLC Number: 

• TP391