If you upload a model with 8k textures, all three versions will be generated.
For example, if you upload a model with source textures that are only 512×512 px, we will only generate a GLB with the original textures. We only generate each version when necessary.
We also generate several versions of GLB with different maximum texture resolutions: Then, we convert that glTF file into a USDZ file with as much of the same data as possible. Sketchfab takes your original 3D data (meshes, objects, animations, etc.) combined with all the material information in 3D Settings, and converts it to the glTF format using PBR materials and textures.
You can also import models directly into your 3D software using Importers.
