Screen Space Ambient Occlusion
When lighting a scene in a way that is similar to real life you want to know how much light can get to a point in space, this is important for small corners and crevices where light photons have a hard time getting to. Ambient Occlusion algorithms are ways to approximate how much light can reach such points, and in this particular implementation I will be focusing on a view space (Screen Space) algorithm. The algorithm runs in a single fragment shader where it samples a random kernel around every fragment for depth values to calculate an occlusion factor, this result is later used in a lighting pass to lower the ambient component by this factor. I don't want to make this post too long since the technique itself is quite old by now and there are tons of resources already on implementing it. Now some for some things I personally encountered while implementing this technique. From what I read at first the algorithm does not play nice with normals calculated from a normal map ...