一种基于GPU的瓦片块四叉树地形绘制算法  

Tiled Block Quadtree Terrain Rendering Algorithm based on GPU

作　　者：王冬[1] 张豫南[1] 李瀚飞[1] 颜南明[1] 

机构地区：[1]装甲兵工程学院控制工程系,北京100072

出　　处：《系统仿真学报》2009年第S1期106-109,共4页Journal of System Simulation

基　　金：兵器装备预先研究(623010102)

摘　　要：分析和比较了两种常用的以块为基础和以四叉树为基础的瓦片块地形绘制算法。利用Shader Model3.0引入的顶点纹理拾取技术,选择基于四叉树的瓦片块地形绘制方法,通过重复使用一小块顶点缓存和索引缓存,结合不同的缩放和平移因子来渲染不同细节层次的瓦片块。将高程值存储在顶点纹理中,在顶点着色器里查找并获取顶点的高程值,避免了在CPU上执行顶点缓存的更新。为了消除不同细节层次的瓦片块拼接时可能产生的裂缝现象,对地形块增加"裙子"顶点,并使增加的裙子三角形和瓦片块地形绘制算法无缝衔接在一起。试验证明该算法充分利用了现代GPU的特性,降低了CPU的负担,能达到较高的绘制效率。This paper compares two of the most common approaches used in the tiled blocks methods: block based simplification and quadtree based simplification. Under quadtree based simplification condition, the terrain was rendered on the GPU using the vertex texture fetch capability in Shader Model 3.0. By reusing a small vertex buffer and index buffer, as well as different scale and bias factor, each block was rendered with different level of detail. To correct the potential cracks between neighboring blocks with different levels, the skirt was added to each block’s border. The skirt was incorporated with the block render method seamlessly. The result shows that the algorithm can not only reduce the CPU load but also reach a higher frame rate.

关 键 词：地形可视化 瓦片块 四叉树 LOD GPU 

分 类 号：TP391.41[自动化与计算机技术—计算机应用技术]