Michael,

We have a weird 3D file problem. I don't know if you can help us or not. It's not a MoI problem, but maybe your knowledge of 3D file formats can shed some light on what's going on.

Our company uses Inventor to create DWG files that are assembled in proprietary software. This software can only use DWG files so that is the go between we're stuck with. Then I take the assembled DWG files into Max 2010 for rendering. Everything works fine unless we start with a 3D file from a 3rd party. If a design firm makes an IGES or SAT or whatever in Solidworks, then we import it into inventor, then we make a DWG, all of the sudden Max 2010 can open the DWG.

Today the same thing happened with a MoI SAT file I made. I know the problem is with Max. But do you have any idea what's going on?

The workaround we found is this.

"Import the offending DWG into Inventor.

Then, export with the NURBS option (instead of the Analytic one) to an IGES file.

Then, export back to AutoCAD saved down to a 2004 DWG."


Don't know why this works, but it does. If you can shed any light on this it would be appreciated.

thanks

Hi Shaun, I'm not entirely sure if I'm following along with what the problem is.

You wrote:

Did you actually mean to say there that Max 2010 is _not_ able to load the DWG file in that case?

I think that there are a couple of different types of entities that can be used in AutoCAD for NURBS objects, there's something like a 3DSOLID and also a BODY type entity. Possibly the difference that you are seeing is due to these different entity types being used.

Is it possible that some objects are closed solids and some are open surfaces? That may end up using different entity types between those cases and maybe that could cause the different handling.

Normally for exporting to 3DS Max from MoI you would want to use the FBX format, but that will transfer polygon data and not NURBS surface data. If you want to bring over NURBS surface data in Max, have you looked at the nPower Power Translator plug-in ?

- Michael

Right. We must go Inventor, to DWG, to Homemade Software, to Max. Max has to use DWG's since that's all our custom software can use.

If we begin with some other program (Solidworks, MoI, anything) then Max 2010 won't use the DWG. It's not an open model problem that I can tell. Solid modeling programs add something to the file that Inventor doesn't. I don't know what that is.

Anyway, this isn't a MoI problem. I was taking a shot in the dark, hoping you would recognize one of the terms I used and possibly have a solution. No big deal.

Thanks for looking.

How are you getting a dwg from MoI? Maybe you should try AutoCAD instead of Inventor as a translator.