分块LOD大规模地形实时渲染算法  

A Block LOD Real-time Rendering Algorithm for Large Scale Terrain

作　　者：李钦[1,2] 戴树岭[2] 赵永嘉[2] 王响[2] 

机构地区：[1]北京航空航天大学大飞机班,北京100191 [2]北京航空航天大学虚拟现实技术与系统国家重点实验室,北京100191

出　　处：《计算机辅助设计与图形学学报》2013年第5期708-713,共6页Journal of Computer-Aided Design & Computer Graphics

摘　　要：针对大规模地形渲染时内存消耗大、帧速率低的问题,提出一种基于线性四叉树的分块层次细节实时渲染算法.在Geomipmapping算法的基础上,首先通过降采样获得相同尺寸的高程数据,结合不同缩放、平移因子,离线建立地形块金字塔结构;然后构建地形块的线性四叉树索引,并定义更为合理的地形块调度准则;最后利用垂直裙带法消除裂缝,设计基于GPU的morphing方法实现顶点的几何过渡.实验结果表明,文中算法能明显减少高程数据存储量,有效地降低了CPU处理时间和GPU渲染批次;在保证画面平滑流畅的同时,达到了较高的渲染速率.In order to solve the problem of high memory space cost and low frame rate in large scale terrain rendering, a block level-of-detail real-time rendering algorithm based on linear quadtree was proposed. It worked on Geomipmapping algorithm. Firstly, digital elevation model was de-sampled to get the same size blocks; terrain pyramid was built with different scales and bias factors offline. Then linear quadtree index of terrain blocks was created, a more reasonable scheduling criterion was defined. Finally, vertical skirt was used to eliminate cracks; GPU-based morphing method was applied to slow down vertex popping. The experimental results show the proposed algorithm could reduce raw data memory consumption, CPU processing time and number of GPU rendering batches significantly, rendering rate is high and smooth.

关 键 词：地形渲染 动态调度 线性四叉树 GPU 

分 类 号：TP391.9[自动化与计算机技术—计算机应用技术]