How to Fix Godot Imported Model Lightmap UV2 Overlap Causing Bake Artifacts

Baked lighting in Godot that shows blotchy dark patches or light bleeding across seams comes from bad UV2. LightmapGI needs a non-overlapping second UV channel to store lighting, and overlapping or absent UV2 makes neighboring surfaces share the same lightmap texels.

How to fix it

1. Generate UV2 on import

In the mesh's Import settings, enable Generate Lightmap UV2 so Godot unwraps a non-overlapping second channel. Reimport, then bake LightmapGI again.

2. Tune texel size and padding

Set a reasonable lightmap texel size and increase island margin so neighboring islands do not bleed into each other at the chosen resolution.

3. Author UV2 for hero assets

For important meshes, create a clean non-overlapping UV2 in your DCC tool for tighter, predictable packing that the auto-unwrap may not match.

Catching the ones you can't reproduce

The hardest version of this to fix is the one you can't reproduce — it only happens on a player's hardware, OS, driver, or save state, under conditions that simply aren't present on your machine. A report that says “it crashed” or “it froze” gives you nothing to act on, so the bug survives release after release while quietly costing you players.

Automatic error capture closes that gap. Each failure arrives with its full stack trace, the device and OS, the build number, and a breadcrumb trail of what the player did right before it broke, so even a failure you have never seen becomes a specific, reproducible issue. Fold identical failures into one signature ranked by how many players each hits, and your worklist sorts itself worst-first instead of arriving as a stream of vague complaints.

This is where a tool like Bugnet earns its place. Its SDK captures every Godot error automatically with the full stack trace plus device, OS, memory, build, and game-state context, folds duplicates into one grouped issue with an occurrence count, and ties each to the build it first appeared on — so you fix the problem that hurts the most players first and confirm it is gone when its signature disappears from the next release.