Using Local Complexity to Accelerate Screen Space Ambient Occlusion

Abstract

In this paper, we introduce a novel method to accelerate Screen Space Ambient Occlusion(SSAO) by exploiting spatial and temporal coherence. SSAO computation only depends on the surrounding pixels which is modeled as screen space local complexity function in this paper. Two pixels with similar local complexity should have close Ambient Occlusion(AO) value. Based on the above observation, the AO value of pixel p in the current frame might be directly adopted from some pixel p' in previous frame. The experimental results indicate that our algorithm can improve the performance of SSAO by 20-40 percent but achieve the similar visual effect.