We use an USDZ-first workflow that tries to keep meshes using Quads and Ngons as long as possible. The standard USD(Z) in fact is older than GLTF2. It was Google who decided against a common standard and forces users and developers for years to depend on Chrome and complex WebApps per every single use case. GLTF2/GLB can only use high poly triangle meshes to achieve smooth surfaces. That's why a conversion of those crippled meshes to OpenUSD becomes bigger. The best way to achieve smooth, compact but still animatable surfaces is to use SubD patches (supported by iOS18+). The main difference between glTF and USDZ is IMHO: glTF is limited to single assets, great for eCommerce. USDZ can either contain a single asset OR it can contain one or many complex interactive scenes with many assets, even sounds. There's even a new 3D web platform that natively loads and renders openUSD files in all browsers I know about: cloudzeta Most of the 40+ KHR_ extensions have not been added to the ISO standard and Google just recently abandoned SceneViewer, their equivalent to Apple's AR Quick Look to force developers and users into relying on WebXR. Update: They abandoned it several years ago by not adding support for any KHR extension. But recently they forbid download from the Playstore mentioning "not supported any longer on this device"

According to the RealityKit docs, the object anchor type should be available not just to visionOS 2.0+, but also to iOS and iPadOS 18.0+ Unfortunately it looks like this won't work with a USDZ launched in ARQL on iOS18. What else is needed or do we have to wait for future releases?

A detailed message how to change / author an asset to meet all criteria is needed desperately.

Manually adding float3[] extent did not help

We won't get an answer related to any future feature or a roadmap. When it's ready, it will be released. I'm very pleased that finally SubD surfaces are supported, a much better way to describe smooth surfaces compared to Draco try polyMeshes as glTF supports. And ObjectCapture now supports Quad-Mes export, needed for SubD workflows. I now hope that 3rd party content optimisers also support it.