Hi! Have weird issue with light baking. Lightmaps look terrible, result similar to what you have with overlapping uv’s. But changing the scale of the model (or a scale in lightmaps) makes lightmap look actually better, still has problems on edges, but AO is in the areas you expect it to be. I’ve baked ambient occlusion with substance painter and used this map as a texture for the same object - works without any issues, so obviously this is not the UVs problem. Tried importing/calculating normals, importing/generating lightmap UVs. So, could it be the issue with the original mesh scale? There’re two images: one with 25x scale in lighmap, where ao kinda works and another with scale 1 and it’s a mess.
Do you have lightmap seam stitching enabled on the MeshRenderer?
yes, it was, but I just tried to bake with and without - nothing has changed. here on a screenshot how lightmap looks with a scale 20, shouldn’t it be bigger? I think scale is the thing that really affects it. I’ve tried to export the mesh from blender with a scale applied and not, nothing has changed. The scale of the mesh is okay in blender, but I wasn’t making this model from scratch - it was converted from stp, so maybe that is an issue?
Increasing the scale in lightmap should make the instance bigger on the lightmap. How big it will be in absolute terms depends on the scale in lightmap, the lightmap resolution in the lighting window, and the size of the mesh. Is that not what you are seeing?
I think you might benefit from authoring lightmap UVs manually here, for example using Blender Unity - Manual: Generating lightmap UVs
Thanks for reply, I don’t have a need to make a specific set of UVs for lightmapping, also tried to generate lightmap UVs - doesn’t work good. I have the solution in externally baked ao, trying to figure out the reason, didn’t have such a behaviour before. There’s a huge mismatch between object’s size and space that it takes on lightmaps, probably that’s the reason
The reason I’m suggesting manually authored UVs is that the lightmap UVs generated automatically by the importer can sometimes be low quality. Just to be clear, they are not the same UVs as are used for regular shading (and are thus likely different from the the UVs used by the external baking tool). Manually authoring UVs can often yield better baking results.
If you are seeing incorrect behavior / lack of scaling when changing the scale in lightmap of a renderer, you should file a bug report.
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Sorry, I didn’t thought about it. Sure, will try to copy my set of uv’s to second channel to try the bake, this explains behaviour, because I had to optimise uv’s to have more texel density.