I am also trying to use this tool to create molecules for 3D printing in a middle school environment. If you can add STL export as an option that would be amazing. The problem with vrml is that it is not commonly supported on inexpensive single extrusion 3D printers and trying to convert the .wrl file to a .stl has been a nightmare. Blender has been somewhat successful, but the color information messes it up and the junction between the colors prints very poorly on some molecules. It is also a lot of extra steps converting a whole class of .wrl’s one at a time. It would be great if we could simply get a direct .stl out of Avogadro so that translation between file formats doesn’t cause problems.
I am using OS X Sierra. More exploration has provided a very convoluted path to achieving a pretty reliable print, but it sure would be great to shave this down with native .stl export.
If I export a .mol2 file from Avogadro, open it in jmol to export it as an .stl, then open it in Meshmixer to convert it to a solid and save the .stl I get a nice looking print without any weird structural issues at the color junction of the bonds.
Try saving with a .stl extension. I can’t remember when STL point-cloud was added to Open Babel, but it should work in recent versions of Avogadro 1.2.