I released the InvToSP script along with a few tutorials which describe how to get an Autodesk Inventor model into Substance Painter for texturing.
Here is a playlist of the tutorials:
-Significant workflow speedup.
-Automatically import high poly and low poly from supplied directory.
-Fix flipped faces using automated re-import.
-Dynamically adjust mesh resolution.
-Fuse objects (collapse, attach) without destroying the explicit normals.
-Supports Unwrella for automatic unwrapping.
-Convert materials to FBX compatible materials.
-Name modifying for Substance Painter “match by name” baking.
-Add nearby objects to high res model for AO baking.
-Assemble standalone parts into final model.
You can find the script and manual here: