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Volumetric Ambient Occlusion for Real-Time Rendering and Games
January/February 2010 (vol. 30 no. 1)
pp. 70-79
László Szirmay-Kalos, Budapest University of Technology and Economics
Tamás Umenhoffer, Budapest University of Technology and Economics
Balázs Tóth, Budapest University of Technology and Economics
László Szécsi, Budapest University of Technology and Economics
Mateu Sbert, University of Girona
This new algorithm, based on GPUs, can compute ambient occlusion to inexpensively approximate global-illumination effects in real-time systems and games. The first step in deriving this algorithm is to examine how ambient occlusion relates to the physically founded rendering equation. The correspondence stems from a fuzzy membership function that defines what constitutes nearby occlusions. The next step is to develop a method to calculate ambient occlusion in real time without precomputation. The algorithm is based on a novel interpretation of ambient occlusion that measures the relative volume of the visible part of the surface's tangent sphere. The new formula's integrand has low variation and thus can be estimated accurately with a few samples.

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Index Terms:
volumetric ambient occlusion, obscurance, GPU, importance sampling, computer graphics, graphics and multimedia
Citation:
László Szirmay-Kalos, Tamás Umenhoffer, Balázs Tóth, László Szécsi, Mateu Sbert, "Volumetric Ambient Occlusion for Real-Time Rendering and Games," IEEE Computer Graphics and Applications, vol. 30, no. 1, pp. 70-79, Jan.-Feb. 2010, doi:10.1109/MCG.2010.19
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