Gaze-Dependent Screen Space Ambient Occlusion

Abstract

The screen space ambient occlusion (SSAO) is a fast global illumination technique, which approximates interreflections between rendered objects. Due to its simplicity, it is often implemented in commercial computer games. However, despite the fact that SSAO calculations take a few milliseconds per frame, a significant computation load is added to the total rendering time. In this work we propose a technique, which accelerates the SSAO calculations using information about observer’s gaze direction captured by the eye tracker. The screen region surrounding the observer’s gaze position is rendered with maximum quality, which is reduced gradually for higher eccentricities. The SSAO quality is varying by changing the number of samples that are used to approximate the SSAO occlusion shadows. The reduced sampling results in almost two-fold acceleration of SSAO with negligible deterioration of the image quality.