Use triangular patches to avoid converting from quads.

[fire]

https://graphics.pixar.com/opensubdiv/docs/release_34.html#triangular-patches-for-loop-subdivision

[tefusion]

I do plan to add loop subdivision. I still think quads are better though when possible. My main problem with loop subdivision was the uneven placement of faces. Seems less severe in those example images though

[fire]

Previously the loop operator trashed this model. Not sure now.

https://sketchfab.com/3d-models/pony-cartoon-885d9f60b3a9429bb4077cfac5653cf9

The headlamp would be corrupted.

The arrows point to the texture seam without subidivision.

[tefusion]

Done with a8602ee5225e8c4ce449a28a22edd4b09d821959. I also tried the example model and the result looked pretty okay to me (level 3):

Some textures near the window and the side of the model still get corrupted/bad results, maybe opensubdiv has some more settings to use to avoid that