GeometryClipmap算法扩展研究.pdf

Vol. 21 Suppl. 12009年10月Journal of System SimulationOct., 2009? 136 ? Geometry Clipmap 算法扩展研究吴 健 1,2 ，曹妍妍 1,2 ，崔志明 1,2 ，王晓军 1,2 （1.苏州大学江苏省计算机信息处理技术重点实验室，江苏 215006；2.苏州大学智能信息处理及应用研究所，江苏 215006）摘要：Geometry Clipmap算法是一种基于GPU优化的LOD算法，在研究Geometry Clipmap算 法的基础上，对该算法进行了扩展。增加了地形数据调度模块，采用地形块预读取和预卸载策略， 实现对海量地形数据的内外存管理。对内存中 Clipmap 堆栈的数据结构进行了改进，取消了原始 算法中 Clipmap Pyramid部分。将 Geometry Instancing 技术引入渲染过程，进一步提升了渲染速 度。实验表明，该算法实用有效，能够满足大规模地形可视化的实时渲染要求。关键词：GPU；地形LOD；Geometry Clipmap；四叉树中图分类号：TP391文献标识码：A文章编号：1004-731X (2009) S1-0136-05Research on the Extension of Geometry Clipmap AlgorithmWU Jian 1,2 , CAO Yan-yan 1,2 , CUI Zhi-ming 1,2 , WANG Xiao-jun 1,2 (1. Provincial Key Laboratory for Computer Information Processing Technology, Soochow University, Suzhou 215006, China;2.The Institute of Intelligent Information Processing and Application, Soochow University, Suzhou 215006, China)Abstract: Geometry Clipmap is a GPU-based LOD algorithm, and this paper extends Geometry Clipmap algorithm on thebasis of doing research on it. It increases the terrain data scheduling module, uses the terrain prefetch and pre-uninstallstrategy to achieve internal and external management of massive terrain datum. It improves the data structure of Clipmapstack in memory and removes the Clipmap Pyramid part of Geometry Clipmap algorithm. Geometry Instancing technology isintroduced into the rendering process to further improve the rendering speed. Experiments show that this algorithm ispractical and effective to meet the needs of real-time rendering large-scale terrain visualization.Key words: GPU; terrain LOD; geometry clipmap; quadtree引 言1