I’m feeling pretty frustrated right now. I’m trying to import my own assets from Blender into Unity, but I keep getting the error message “There are X objects in the Scene with overlapping UV’s” for every asset. I’ve carefully unwrapped the UV maps and included them in the model. To illustrate my problem, I’ve created a very simple door in Blender (Picture 1).
I marked the sharp edges as seams and unwrapped the UV map. For this simple model, the UV map looks good. When I click on “Select > Select Overlap,” no errors are shown. As mentioned, this is a very basic model meant to highlight the issue I’m facing (Picture 2).
However, when I export it as an FBX and import it into Unity, I get the “Overlapping UVs” error during light baking. In Unity’s UV Overlapping View, the following is displayed (See Picture 3).
When I double-check in Blender with the UV grid, I can’t find any overlapping UVs (See Picture 4).
Lightmap UVs and texture UVs are seperate, but if your main UV unwrap has no overlaps, you can absolutely just use primary UVs as lightmap UVs. I’d read both the docs I linked for more info on lightmap UVs and how to generate them. Unity can also auto generate lightmap UVs in the model import settings, but if your models are already unwrapped, you shouldn’t nessesarily need it. Keep in mind that the lightmap resolution being too low might also introduce overlap if the size of a lightmap texel is larger than the padding between UV islands.
You probably need to increase the margin between UV islands. If they are too close together, this can lead to lightmap bleeding. If you generate Lightmap UVs in Unity, you can adjust the settings to eliminate overlap.
thank you both so much for your help! It turns out you were right. I increased the margin between UV islands from 0.001 to 0.05 in Blender during the UV unwrap, and voilà, no more UV overlap errors. It seems that was exactly the issue
Thanks a lot for your help - it saved me a lot of trouble!
