MeshBuilder's .with_double_sided() doesn't work

[Deleted user]

In the basic cube and the scene-viewer examples, and models made in Blender and imported with rend3-gltf, calling .with_double_sided() doesn't seem to do anything:

Inside the scifi helmet:

Cutting into the stereo:

Note that the old aviator helmet model already has inward facing surfaces on the inside.

To see it in the scene viewer example, add .with_double_sided() in rend3-gltf/src/lib.rs after line 707, and it's also useful to slow the camera movement speed in scene-viewer/src/lib.rs line 538 with * 0.02.

[Deleted user]

Hm, i can't see anywhere the function .double_side is actually being called