An Occlusion Grid Culling Algorithm Based on LOD Models
基于层次细节模型的遮挡裁剪算法

Occlusion culling and LOD(Level of Details) both are effective techniques in accelerating the rendering process of 3D large scene. An algorithm framework which integrate occlusion culling and LOD is proposed in this paper. It partitions the scene volume into a hierarchical structure during the preprocess stage, and in runtime, it uses occlusion culling in the high level to cull the invisible scene, while view-dependent simplification are used in the low level to show the detail. This algorithm is mainly based on Luebke's work of mesh simplification and Heinrich's work of lazy occlusion grid culling in the image space, it extends the data structure of 'vertex tree' to support occlusion culling and also uses an occlusion grid buffer to reduce the number of expensive occlusion queries at pixel-level. Experiment result shows that significant speedup is achieved through our algorithm.