AutoCAD Inventor :: How To Use STL And Mesh Files

We are trying to use 3d scanned data in Inventor to facilitate our design process. We don't need perfect and good looking 3d scanned models ready to produce, but we need some accurate measurements from holes and faces that we can use to design our own products.

So mine problem is: How I can get those scanned meshes to Inventor that I can get some dimensions from it, project some geometry to my sketches, add some constraints between scanned surface and mine designs, etc...?

I have tried some Add-Ins like Sycode's STLImport and Sycode's software called Mesh To Solid to get those mesh files open and I can open those "converted" files in Inventor, but those are only some kind of surfaces called Composite or Surface which consist of tiny triangles.