USDZExport creates an empty (visually) USDZ file from a GLTF created in the browser

Continuation from previously filed issue

Describe the bug

Trying to create a GLTF in the browser and convert it to USDZ without needing to download a GLTF file first. TLDR; On-the-fly-USDZ creation and download

It successfully creates a GLTF in memory, loads the GLTF after wrapping in blob, and exports the usdz file (in theory).

I can see the object as GLTF in the Three.js editor and Apple’s Reality Convertor but not in any QuickLook view (phone or Finder)

Source of export here: https://github.com/jeffscottward/r3f-to-ar/blob/main/src/exporters/usdzExporter.js Repo here: https://github.com/jeffscottward/r3f-to-ar

To Reproduce

git clone https://github.com/jeffscottward/r3f-to-ar/
yarn && yarn start

Click the model - it should download 2 files, 1 gltf and 1 usdz

Platform:

Device: Laptop OS: MacOS Browser: Chrome Three.js version: “^0.132.2”

[mrdoob]

I’ll take care of this 👍

[mrdoob]

Maybe we can add a warning somewhere at the following place to inform users if they are exporting meshes with an unsupported material?

https://github.com/mrdoob/three.js/blob/183ae6afcdb6323d6a2075811073ed8767d6c2fc/examples/jsm/exporters/USDZExporter.js#L20

Done. https://github.com/mrdoob/three.js/commit/6e4f7a5fa7f1944e941019a655ae50868f2a883a