Hello @ajinkya ,
welcome to this moderated Azure community forum.
As @AshokPeddakotla-MSFT mentioned, only files with the GTLF and GLB are supported.
These files can be created with a number of 3D tools, including 3DPaint.
The .usd file can be imported using the popular open-source Blender tool.
After importing, you can export it via Blender to glTF 2.0 format with the .glb/.gltf extension.
I have used Blender to export a number of times and it works fine form me.
Please keep the size of the file below 100Mb so 3D Scenes studio will keep performing.
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