The format of the file you are converting to.
Supported input formats
3d 3dm 3ds 3mf ac ac3d acc amf amj ase ask b3d blend brep bvh cob csm dae dxf enff fbx gcode glb gltf ifc iges igs lwo lws lxo md2 md3 md5 mdc mdl mot ms3d nc ndo nff obj off ogex ply pmx prj q3o q3s scn sib smd step stl stp uc usda usdc usdz vta x xgl xml zgl