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hii

Why does the interior of the mouth gets darkened by natural shadow when there is light shined on it?

motoole2

@hii Not sure if I understand the question here, but let me give this a shot. The "without AO map" image represents a diffuse shading model, where intensity variations are purely a function of surface normal and lighting direction(s), but ignores how the model's geometry occludes light. The interior of the mouth is dark for the "with AO map" image because only a fraction of the hemisphere is visible for points in the mouth when taking model geometry into account.

crabbage

why does baking enhance shading?

motoole2

@crabbage Computing the ambient occlusion map provides more realistic shading of a model, because it takes the model's geometry into account (e.g., like the shading that occurs on the inside of the hippo's mouth). The problem is that computing the ambient occlusion map is expensive---it requires solving a complex integral. So rather than do this every frame, one can pre-compute the ambient occlusion map in a pre-processing step and texture map a model with the ambient occlusion map. Assuming that the geometry does not change, this is an effective and efficient way to shade your geometry in a more realistic way. If your geometry changes drastically, then the ambient occlusion map needs to be recomputed.