I had a quick look at one or two 3D models from
<https://3d.si.edu/cc0>, and I see OBJ, glTF (OpenGL Transfer Format)
and GLB (binary version of glTF) options available. These are all open
formats, well-supported in non-proprietary software.
+1 for using open formats.
Dept. of Computer Science
University of Waikato, NZ
+64 (7) 858-5174