Fix lightmapper seam blending #91985
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| @@ -428,6 +428,7 @@ void LightmapperRD::_create_acceleration_structures(RenderingDevice *rd, Size2i | |||
| SWAP(edge.a, edge.b); | |||
| SWAP(edge.na, edge.nb); | |||
| SWAP(uv2.a, uv2.b); | |||
| SWAP(uv2.indices.x, uv2.indices.y); | |||
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Does this also fix #90929? |
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Tested locally, this doesn't appear to do much against the seams in the Global Illumination demo project:
| Before | After (this PR) |
|---|---|
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Testing project: global_illumination.zip (bake the LightmapGIAll node)
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These ones seem to be caused by the lightmap UVs being too small and packed too tightly, making the texture bleed onto its neighbours. Edit: The lightmap looks like this, so leaks are bound to occur: |
yeah because those aren't caused by wrong vertex indeces. There's more than one issue with lightmaps If I had to guess those are most likely due to wrong UV offset calculation during seam blending |
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I was so happy that I found the bug, only to see now that you beat me to it. (Why doesn't Github notify me when there's a PR that would close an issue that I'm subscribed to?) When the bug is fixed, the blending effect is so subtle that it's difficult to be sure whether it's working or just broken to the point where it does nothing. But there are actually some seams that look smoother with it. The left is with seam blending disabled, the right is with the fix.
While I was debugging, I noticed that the texels that are blended often don't perfectly line up with the actual seam. But that is a completely different issue. |
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Thanks! Great work tracking this down 🥇 |
Closes #91614