This technique lives in the same space as precomputed radiance transfer, but can be implemented in a much simpler shader, particularly if you use the bent normal to look into an irradiance map to implement image based lighting as described in the wikipedia article below. http://www.ozone3d.net/tutorials/ambient_occlusion.php http://www.cs.unc.edu/~coombe/research/ao/ http://en.wikipedia.org/wiki/Ambient_occlusion http://download.nvidia.com/developer/GPU_Gems_2/GPU_Gems2_ch14.pdf