Textures are supported by the .obj/.mtl and .FBX** file formats.
To upload .obj/.mtl files with textures, place .obj, .mtl and texture files; either .jpeg, .jpg or .png's into .zip file. Upload .zip file. (Ensure .obj and .zip have the same name).
For .FBX files with non-embedded texture files, place all files into a .zip file along with the .FBX and all texture files; either .jpeg, .jpg or png's. Upload .zip file.
**For .FBX files, we currently only support embedded .FBX formats. To export or convert a file to an embedded .FBX file we recommend using blender. https://www.blender.org/.