Abstract: 3D realistic terrain generation is a hot topic in computer graphics field.Real-time Optimal Adaptive Meshes（ROAM） algorithm based on level of detail technique is introduced to render terrain dynamically.Visibility culling technology of projection based on bounding box of the terrain block is used.A algorithm that combines nested bounding sphere method with screen space error method is introduced to optimize the error criterion to improve the speed of terrain rendering.Implementation method of the level of detail model in terrain rendering process is given.Experimental results show that the method reduces expenses and improves real-time rendering speed under the premise of guaranteeing that it is in a certain terrain rendering effect.

Key words: terrain rendering, Level Of Detail（LOD）, real-time optimal adaptive meshes, visibility culling, nested bounding sphere

摘要： 三维真实感地形的生成一直是计算机图形学领域中的焦点课题，研究了基于层次细节的实时优化自适应网格动态地形渲染算法，采用了基于地形块包围盒的可见性投影剔除技术的实时优化策略，提出了嵌套包围球方法和屏幕空间误差法相结合的优化算法来改进误差判据，以提高地形绘制的快速性，给出了该层次细节模型在地形渲染中的实现方法。实验证明，通过对实时优化自适应网格算法的实现和优化，在保证一定的地形渲染效果的前提下，减少了开销同时提高了实时渲染速度。

关键词: 地形渲染, 细节层次, 实时优化自适应网格, 可见性剔除, 嵌套包围球