地形绘制一直是图形学研究的热点问题，尤其是球面地形绘制，其在形状和数据组织方面比平面地形绘制更加复杂。在已有球面地形绘制算法的基础上，提出一种基于Geometry Clipmap的球面地形剖分与绘制方法。该方法以构建正二十面体球面网格为基础，将正二十面体划分为十个菱形区域，采用球面菱形网格的剖分，针对每个菱形区域的周边网格进行重新剖分和组合，形成一个虚拟的3×3的大菱形区域，扩大了Clipmap的活动范围，并在一定程度上解决了Clipmap的跨边界问题。实验结果表明了本文方法的可行性和有效性。

Large terrain rendering is hotspot in Computer Graphics, especially the spherical terrain rendering, which is more complicated in shape and data organization. Based on researching in spherical terrain rendering method, we propose a new spherical terrain rendering method using Geometry Clipmap. First construct an icosahedron model, and then split the icosahedron into ten main diamonds, and use spherical Sphere Quad Trees (SQT) model to ensure Geometry Clipmap can be used in every diamond, what else, grids around the main diamond are partitioned and composed to a bigger virtual diamond terrain in 3×3 size, which enlarge clipmaps' extent and solve the boundary crossing problem to a extent, and the Geometry Clipmap can be used in the big diamond. The result illustrates feasibility and effectivity of the method.