McGuire, MorganMara, MichaelLuebke, DavidCarsten Dachsbacher and Jacob Munkberg and Jacopo Pantaleoni2013-10-282013-10-282012978-3-905674-41-52079-8679https://doi.org/10.2312/EGGH/HPG12/097-103This paper presents a set of architecture-aware performance and integration improvements for a recent screenspace ambient obscurance algorithm. These improvements collectively produce a 7x performance increase at 2560 x1600, generalize the algorithm to both forward and deferred renderers, and eliminate the radius- and scene-dependence of the previous algorithm to provide a hard real-time guarantee of fixed execution time. The optimizations build on three strategies: pre-filter the depth buffer to maximize memory hierarchy efficiency; reduce total bandwidth by carefully reconstructing positions and normals at high precision from a depth buffer; and exploit low-level intra- and inter-thread techniques for parallel, floating-point architectures.