Wrong mesh winding for negative scaled nodes

[abbaswasim]

This is GLTFKit issue and haven't tried GLTFKit2 yet but I have a feeling (quick search didn't find the fix) this project will be suffering from the same issue too and since this one is the newer I am creating issue here.

The issue is that according to glTF spec:

When a mesh primitive uses any triangle-based topology (i.e., triangles, triangle strip, or triangle fan), the determinant of the node’s global transform defines the winding order of that primitive. If the determinant is a positive value, the winding order triangle faces is counterclockwise; in the opposite case, the winding order is clockwise.

I have tried GLTFKit with unit_cube.zip model to show the issue. You will see an inside out cube.

[warrenm]

This is a renderer-level concern, and GLTFKit2 doesn't provide any renderers. It seems that SceneKit, which is used in the sample viewer included with this project, handles this situation correctly.

[abbaswasim]

humn, interesting. I saw the issue in GLTFKit which does provide a viewer so assumed it might exist here too.

[warrenm]

Feel free to file an issue against the appropriate project. Closing.