ABSTRACT
Standard online occlusion culling is able to vastly improve the rasterization performance of walkthrough applications by identifying large parts of the scene as invisible from the camera and rendering only the visible geometry. This algorithm remedies this situation by quickly detecting and culling the geometry that does not contribute to the shadow in the final image. This method is particularly useful for shadow mapping in large-scale outdoor scenes. The proposed method generalizes trivially over a wide class of occlusion culling algorithms as long as they are compatible with receiver masking, a property that holds for all rasterization-based algorithms. This chapter demonstrates the benefits of the algorithm using a reference implementation in the context of large directional light sources and note that the small overhead of generating the receiver mask is easily compensated by the performance gains during shadow-map generation.
