Rhinoceros

This tutorial is useful and gives you quite a good overview how Inventor and Rhino can work togehter. If you have a specific problem how to export from Inventor and import into Rhino you won't find any detailled settings you have to make to get to the best result if you have surfacing problems (badly trimmed, gaps, etc). IGES files can be exported with different settings from Inventor to Rhino so still sometimes there's trial and error left...