Limitations of USDZ
“PBR” shading / look development
One single material applied to everything (currently supported material: StingrayPBS). Note that StingrayPBS UV offset and UV scale must be left with the default settings.
No indirect illumination
max 100K polygons for the whole USDZ asset you want to output
avoid N-gons and non-manifold topology
no subdivision surfaces
no volumes or fog
Only one single set of PBR textures
Only one single UV set, with all UVs packed in within a [0,1] region, no overlapping UVs
No per-face assignments
Max 10 seconds of animation (240 frames)
Only affine transformation are allowed in animation: this means only translate, rotate and scale are possible in USDZ (no deformations) — See video above.