When exporting usdz in Rhino 8, the material is shown with rounded corners for some reason. I tested with a simple cube. When you export to fbx and then convert to usdz outside of Rhino, the material is shown correctly. Is there something that I need to adjust to export the usdz file without the strange rounded corners?
Here is the comparison (quick look on mac):
Above is direct usdz export from Rhino 8
and here is the converted usdz from Rhino fbx export.