Screen Space Hair Self Shadowing by Translucent Hybrid Ambient Occlusion

Abstract

Screen space ambient occlusion is a very efficient means to capture the shadows caused by adjacent objects. However it is incapable of expressing transparency of objects. We introduce an approach which behaves like the combination of ambient occlusion and translucency. This method is an extension of the traditional screen space ambient occlusion algorithm with extra density field input. It can be applied on rendering mesh objects, and moreover it is very suitable for rendering complex hair models. We use the new algorithm to approximate light attenuation though semi-transparent hairs at real-time. Our method is implemented on common GPU, and independent from pre-computation. When it is used in environment lighting, the hair shading is visually similar to however one order of magnitude faster than existing algorithm.