Occluder shadows for fast walkthroughs of urban environments

This paper describes a new algorithm that employs image-based rendering for fast occlusion culling in complex urban environments. It exploits graphics hardware to render and automatically combine a relatively large set of occ luders. The algorithm is fast to calculate and therefore also useful for sc enes of moderate complexity and walkthroughs with over 20 frames per second . Occlusion is calculated dynamically and does not rely on any visibility p recalculation or occluder preselection. Speed-ups of one order of magnitude can be obtained.