I'm trying to find a good solution to cleanly translate a simple Houdini curve (an open polyline or NURBS curve) for import in AutoCAD. Ideally .dwg format. I could be happy with just getting into Illustrator, but the real challenge is AutoCAD.

To be honest, I've already done it. Export as IGES, then import in AutoCAD using a custom importer:
http://www.sharewareconnection.com/iges-import-for-autocad.htm [sharewareconnection.com]
It's 200$ though, and I'm looking for a free, and (ideally) clean and easy solution.

Shoot!

I haven't tried but polygon lines might transfer via .dxf files.

There are some differences how houdini outputs header information in dxf files then how it is in autocad. Most of the time i was getting a nasty crash while loading them. Looks like autocad is looking for some lines which are not exported from houdini. On the other hand Rhino or Bricscad handle them correctly. Sadly houdini is not a perfect tool for working together with CAD Software. For me though IGES and Rhino (as a converter) combination is quite decent solution.
Cheers,
Kuba

Yeah, dxf is not an option. The Houdini export to dxf insists on triangulating (even curves), with disastrous results.

I'll try the Rhino way, but I'm open for more suggestions.

Thanks!

What I would like to see in the next houdini releases is opnNurbs and dwg support. That would be a huge improvement and would link the gap between most of the CAD software.

I'm on Mac and I got lucky: there's a free-to-use dev version of Rhino available for download. Rhino does a superb job at importing my Houdini IGES, and exporting it as a dwg. It imports flawlessly into Illustrator and AutoCAD.

http://community.irhino3d.com/ [community.irhino3d.com]

Right now the best option I have found is saving as .obj and exporting them to .dxf through Cinema 4D. As mentioned earlier curves export from Houdini to .dxf are triangulating and there is to much clean up involved.
It's been a few years now since this post and I am looking for a better solution. One that preferably involves ONLY one software, Houdini.

maybe this will help someone
I export the curve through a "File Cache" node ---> Import in Sketchup ---> Export from Sketchup to dxf
And it's work fine, tested import in 3d max - everything works