Strange lighting, black walls

Importing one big, single mesh from Blender into Godot causes some walls to not receive any lighting.

All surfaces throughout the level that are facing that direction are not receiving lighting.

This screenshot is without a WorldEnv and without DirectionalLight3D.

  • v4.2.1-stable.official, forward+
  • Windows 10
  • Vulkan, nvidia 3080
  • Using .blend directly into my Godot project

In Blender the wall has no trouble receiving lighting:

And, another side (of all meshes) in the level will show a different issue where a omnilight cuts off abruptly:

In conclusion, If I have a cube like in the last picture; 4 faces will show lighting correctly, one face will be totally black (always the same direction), one face will receive partial lighting (always the same direction). Top/bottom faces are OK.

What is also strange is that when I put a light inside the mesh, the face that would otherwise be black will receive lighting. As if it thinks the inside of a face is the outside if that makes sense.

A bit strange., any clue?

Interesting, I fixed it by disabling ‘alpha’ in the material properties in Blender.

Maybe it is still a Godot bug though.

Moved to Help section and added tags, also marked as solved as you found a solution.