Forgot to reply to list as well. -------- Original Message -------- Subject: Re: [Chimera-users] Exporting .stl Date: Tue, 30 Nov 2010 13:33:23 -0800 From: Greg Couch <gregc@cgl.ucsf.edu> To: Dennis Kolva <dk429@cornell.edu> On 11/25/2010 06:29 PM, Dennis Kolva wrote:

I have been using Chimera to export .stl files of proteins and RNA for 3D printing. The surface models print OK, but sticks or ribbons choke the printer. I looked close at the output meshes, and they have many extra surfaces which should be removed to make "legal" .stl format.

Is that portion of the code open source? I'd like to take a closer look and see if it's possible to fix. It would be much easier to rectify the bad surfaces upon creation, rather than trying to remove them by post-processing.

Thanks,

Dennis Kolva Cornell U.

Presumably , you don't have a Z-Corp printer and their ZPrint software, otherwise you would output VRML from chimera and have ZPrint do the proper conversion to STL. So yes, the source code is available at http://plato.cgl.ucsf.edu/trac/chimera/browser/trunk/apps/x3d2/stl, and we would welcome improvements. I believe that the problem is that chimera does not output manifold geometry and that the X3D to STL converter would need to perform CSG operations on all of the geometry, especially the spheres and cylinders, to eliminate interpenetrating surfaces. Another issue to consider is what to do about ribbons and cylinders that are too thin for the printer you're using. Feel free to contact me directly with questions about the code or use the chimera developers mailing list, chimera-dev@cgl.ucsf.edu, Greg