Abstract: In many applications, three dimensional terrain scene has to be updated in local area with high-precision data, in order to build a local high-precision scene. Aiming at the dynamic updating of local terrain data, this paper puts forward a GPU tessellation based “Mosaic” algorithm of local high precision terrain. Through the interpolation and subdivision on the terrain grid within the updating area in GPU to increase the number of triangles, as a result, the geometrical accuracy of the local terrain model is improved without increasing the bandwidth of the memory and video memory. The results show that the precision of updating area meets the demand and this algorithm is obviously better than the common method in execution efficiency.

Key words: three dimensional terrain scene, local terrain updating, real-time grid tessellation, GPU algorithm

摘要： 三维地形场景在很多应用中需要通过及时更新局部高精度地形数据来构建重点区域的精细场景，针对局部区域地形数据的动态更新，提出了基于GPU实时网格细分的局部高精度地形的“镶嵌”算法；通过在GPU中对更新区域的地形网格实时插值细分来增加三角面片数，提高地形模型的几何精度，在有效保证更新区域地形绘制精度的同时，并没有增加内存与显存之间的数据传输压力。实验结果表明，更新区域的绘制精度能够满足要求，且执行效率优于现有的常用算法。

关键词: 三维地形场景, 局部地形更新, 实时网格细分, GPU算法