Why is MeshInstance.GetSurfaceMaterial() returning null?

kitfox

I'm trying to scan the nodes of an imported scene to replace its materials. While the MeshInstance nodes show attached materials when I expand them in the inspector, and while MeshInstance .GetActiveMaterial() is returning it, GetSurfaceMaterial() return null. Why is this? I'd rather get the surface material directly since GetActiveMaterial() seems to check several things to get its result.

cybereality

The materials on the mesh don't really work. I guess it's a bug, sometimes they appear to work but the lighting is wrong or other glitches. Only use the material override on the mesh instance.

cybereality

On Godot 3.x you would do this:

var mat = obj.get_surface_material(0)