Bent Normals and Cones in Screen-space

Abstract

Ambient occlusion (AO) is a popular technique for real-time as well as offline rendering. One of its benefits is a gain in efficiency due to the fact that occlusion and shading are decoupled which results in an average occlusion that modulates the surface shading. Its main drawback is a loss of realism due to the lack of directional occlusion and lighting. As a solution, the use of bent normals was proposed for offline rendering. This work describes how to compute bent normals and bent cones in combination with screen-space ambient occlusion. These extensions combine the speed and simplicity of AO with physically more plausible lighting.