Screen Space Ambient Occlusion Using Partial Scene Representation

Abstract

Screen space ambient occlusion (SSAO) is a technique in real-time rendering forapproximating amount by which a point on a surface is occluded by surrounding geometry, whichhelps in adding soft shadows to diffuse objects. Most of the current methods use the depth bufferas an approximation to scene geometry to sample the occlusion factor. We introduce a noveltechnique which uses a partial representation of the scene (here triangle information in screenspace) using compact triangle storage and a ray-marching approach to find a betterapproximation of the occlusion factor.