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This includes big improvement: - The horizon search is decoupled from the BSDF evaluation. This means using multiple BSDF nodes have a much lower impact when enbaling AO. - The horizon search is optimized by splitting the search into 4 corners searching similar directions to help which GPU cache coherence. - The AO options are now uniforms and do not trigger shader recompilation (aka. freeze UI). - Include a quality slider similar to the SSR one. - Add a switch for disabling bounce light approximation. - Fix problem with Bent Normals when occlusion get very dark. - Add a denoise option to that takes the neighbors pixel values via glsl derivatives. This reduces noise but exhibit 2x2 blocky artifacts. The downside : Separating the horizon search uses more memory (~3MB for each samples on HD viewport). We could lower the bit depth to 4bit per horizon but it produce noticeable banding (might be fixed with some dithering).