Accelerated occlusion culling using shadow frusta

: Many applications in computer graphics and virtual environments need to render datasets with large numbers of primitives and high depth complexityatinteractive rates. However, standard techniques like view frustum culling and a hardware z-bu#er are unable to display datasets composed of hundred of thousands of polygons at interactive frame rates on current high-end graphics systems. We add a #conservative" visibility culling stage to the rendering pipeline, attempting to identify and avoid processing of occluded polygons. Given a moving viewpoint, the algorithm dynamically chooses a set of occluders. Each occluder is used to compute a shadow frustum, and all primitives contained within this frustum are culled. The algorithm hierarchicallytraverses the model, culling out parts not visible from the current viewpoint using e#cient, robust, and in some cases specialized interference detection algorithms. The algorithm's performance varies with the location of the viewpoint and the depth...