This is my first post to the Unity community. I have a simple scene that I began working on in Unity 4. The lightmapping back then worked flawlessly, but since upgrading to Unity 5, I can’t get a single usable bake. I’ve tried increasing and decreasing the padding and resolution in Baked GI, all three directional modes, AO and no AO, final gather and not, etc.
I’ve attached two pictures; both are from the same bake, just in different areas of the scene. One shows extreme black blotches which is what I am seeing in 75% of my scene. The other image is a low quality version of what the other 75% should be looking like. These walls don’t have many vertices, they are simple two-triangle repeating planes. I made this model in Blender and imported it as an .obj, then generated the UV map in Unity. Again, this worked in Unity 4 but is failing in Unity 5.
I once had a blender model where i purpusely used overlapping UVs and experienced the same light baking problems. It makes sense that using such UV maps with light baking will mess things up, since one pixel of the light map covers more than one point of the model (how should this be handled?).
I never tried it, but i think the right way to do this would be to use two different UV maps. One for the texture and one for baked light. Found this thread about it:
The best solution I found is to make sure your UV maps are mapped optimally/properly. In many cases, 3D applications like Blender and Cinema 4D will automatically try mapping, which causes overlapping polys on the UV map.
