The normal map feature at the moment always uses a right-handed coordinate system to distort the normals, so if the UV coordinates are mirrored this will not work correctly. I would expect the normal perturbations in the mirrored part to be flipped upside down, but not sideways, is that correct?matej wrote:There is a problem with normal-mapping when mirrored UVs are involved. It probably has to do with the new invert ability of normal maps (which is a nice feature, btw).
The model below is an early stage project I'm working on. It's UVs are mirrored down the middle. This results in the left side to look inverted, when the normal map is applied to the normal channel. If you invert the normal map the effect just flips - now the right side looks inverted. There aren't any inverted normals or anything wrong with the mesh. First pic is diffuse & normal on their respective channels
Second pic is only normal applied to diffuse channel (so you can see everything is ok with the texture)
The last is only normal applied to normal channel
I hope this wont be too problematic to solve, cause using overlapping mirrored UVs saves a ton of work & VRAM
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Roeland
