Abstract: This paper uses the triangle bitree data structure，divides the terrain with the suitable size，so only deal with local terrain each time；proposes a mixed method of reasonable clip with bounding sphere and bounding cone，and produces adaptive levels of detail in accordance with the change of viewport and the corresponding vertex error.Thus reduces the number of redundant operations，avoids the problem of the occurrence of cracks and jumping feeling in details conversion，reduces the amount of data processing and the computational complexity.

摘要： 使用三角形二叉树数据结构，对地形进行合适的分块处理，使得每次只处理局部的地形；提出包围球与包围圆锥混合的方法对地形进行合理的裁剪，并依据视点变化和对应的顶点误差生成自适应地形层次细节。减少了大量的冗余操作，避免了裂缝的出现和细节转换时地形的跳跃问题，减少了数据处理量并降低了计算复杂度。