How To Open And Save Inventor Files In AutoCAD?

In my last two posts (“How To Get DWG Solids Into Inventor” and “How To Get DWG Solids From Inventor“) I explained the issues in getting DWG solids in and out of Inventor. While it is possible, the procedure is not as simple and straightforward as it should be. In this post, I would like talk about getting Inventor solids in an out of AutoCAD. Well, to put is simply, you cannot. At least I could not find a way whereby AutoCAD could read or write Inventor part and assembly files.

I understand that writing Inventor assembly files from AutoCAD does not make sense. But at least Autodesk should have allowed AutoCAD to save Inventor part files. And there is definitely no excuse for AutoCAD not to be able to read Inventor parts and assemblies. Autodesk has even given 3ds Max to ability to read Inventor parts and assemblies, but not AutoCAD. Obviously they want 3D data to move from AutoCAD to Inventor to 3ds Max and not the other way around.

If an AutoCAD user is given an Inventor part or assembly file, there is no way he can access the 3D data in it, which is frustrating because AutoCAD has some neat tools to edit 3D solid objects. He would need to go back to the person who gave him the Inventor file and ask him to export to an ACIS SAT file which he could then import into AutoCAD. If that is not possible then the AutoCAD user is stuck up.

In my opinion, the ACIS SAT route is not a very good one. Autodesk is stuck at ACIS SAT version 7.0 which is years old. That is the version when they purchased the ACIS source code from Spatial and went their own way to develop their own modeling kernel. As far as I know, none of Autodesk’s products write SAT files later than version 7.0. At least Inventor does not. So apart from spitting geometry and properties that were available in ACIS 7.0, Autodesk has no way of transferring any new type of data (geometry and/or properties) by using SAT as the intermediate file format between Inventor and AutoCAD.

Shockingly, AutoCAD cannot even read 3ds Max files. AutoCAD and 3ds Max users need to use the ancient and hoplessly outdated 3DS format (remember the old 3D Studio?) to get data from 3ds Max into AutoCAD. AutoCAD’s Import command paints the sad picture quite clearly. You can import SAT, 3DS, DGN (Microstation) and WMF (Windows Metafile), that’s all.

That’s why I laugh when I hear Autodesk people talk about 100% compatibility between their products. Because it is a joke and for paying Autodesk customers its not funny.

Update (13-Nov-2009)

There is a way to open Inventor part and assembly files in AutoCAD without requiring a license of Inventor. Click here to find out how.