Rendering issues with GLTF models

[cbscribe]

Godot version

4.0 beta2

System information

MacOS 12.5

Issue description

Imported GLTF models are rendering incorrectly or displaying artifacts. These same models render correctly in 3.x.

• Shadowed faces displaying line artifacts
  3.x:
  
  4.0:
  

• Some meshes not rendering correctly
  3.x:
  
  4.0:
  

Even stranger, in the latter model, which contains separate meshes for the body and the 5 wheels, toggling visibility on different meshes affects the rendering of others, sometimes in irreversible ways.

I've attached the model file here as well.
suv.glb.zip
cartoon_plane.glb.zip

Steps to reproduce

Import .glb file and create an instanced scene.

Minimal reproduction project

No response

[fire]

@clayjohn on the suv.glb, if i duplicate the second material on the missing wheel the material appears again. Any ideas?

[clayjohn]

Shadowed faces displaying line artifacts

This is shadow acne from the default DirectionalLight3D. The issue is already tracked in #54523 and a draft PR has already been made #55757

Some meshes not rendering correctly

I've run into this issue with imported GLTF files as well. But like Fire mentions it goes away when you make the material unique. It also is not reproducible using non-imported materials. My guess is it is an issue with the GLTF material importer but I am not familiar with that code.

[lyuma]

The artifacts have been solved since the release of Godot 4.0.

Thanks for the report.