Masking the Depth Buffer Hardware Accelerated Ambient Occlusion Techniques on GPUs Overview on Screen Space Ambient Occlusion Techniques Real-Time Depth Buffer Based Ambient Occlusion Source code of SSAO shader used in Crysis Approximating Dynamic Global Illumination in Image Space Accumulative Screen Space Ambient Occlusion NVIDIA has integrated SSAO into drivers Several methods of SSAO are described in ShaderX7 book SSAO Shader ( Russian ) SSAO Tutorial, extension of the technique used in Crysis Shading Computer graphics 3D computer graphics Global illumination algorithms