Lightmap glitches


I think the resolution of lightmap is to low.

Press Alt+0 or select Lightmap Density mode in viewport. And see how look your lightmap on the model. Each UV patch must have at least 3 pixels.

Also you need to snap edges of the UV patches to edges of pixels. This help to avoid interpolation errors.

You do not need to set the resolution equal to the power of two for lightmap. If 512 is not enough, but 1024 is too much, then you can set something like a 734, if it will give good result for you.

The next trick is to split the mesh and you can create highly detailed lightmap for this part of the mesh.


I had a problem on lightmap for one kind of mesh in my scene. I have already test these parameters : lightmap res, SSR, light bounce, lighting quality. Nothing seems to fix this.

NB : this doesn’t moire. It’s really lightmap.

Any idea ?

Thanks for help and explanations on how to work on lightmaps.
After changing res to 1024 (maybe to high), it solves my problem.