Max McGuire, NVidia, and Williams College have just published a new paper that presents a new algorithm for Ambient Occlusion Volumes. From the abstract:
It combines known pieces in a new way to achieve substantially improved quality over fast methods and substantially improved performance compared to accurate methods. Intuitively, it computes the analog of a shadow volume for ambient light around each polygon, and then applies a tunable occlusion function within the region it encloses. The algorithm operates on dynamic triangle meshes and produces output that is comparable to ray traced occlusion for many scenes. The algorithm’s performance on modern GPUs is largely independent of geometric complexity and is dominated by fill rate, as is the case with most deferred shading algorithms.
The algorithms are compared against the Crytek algorithm, although the Crytek algorithm does not support the variable sample counts supported by the other options. The results (compiled into the table on page 8) show significantly reduced render times (some down to 2.9ms from 12ms) with a lower error metric.
Download the paper here (view online).
