Is there a simple way to create a 3D object with a custom image as a texture? Reality Composer only allows a material and a color, and without that, I'll have to dip into a far more complex 3D app. I'd really, really like to use USDZ more in Motion, for pre-viz and prototyping, but without texture editing it's quite limited. Have I missed something? :)
There are various third-party DCCs with great USD support that let you create complex 3D object with textures and export as USD. You can then use Reality Converter to convert those to USDZ to import into Motion.
Another approach: three.js (web render engine) can actually create USDZs on the fly from 3D scenes. A colleague used that recently for USDZ AR files with changeable textures on https://webweb.jetzt/ar-gallery/ar-gallery.html
Also take a look at the Explore USD tools and rendering session tomorrow. You can now change materials properties in RealityConverter! (edited)
Another thing that might help for making quick adjustments: the browser-based three.js editor at https://threejs.org/editor.