Renderosity does not currently have a 3D printing forum. There are several 3D printing forums out there, but they are usually specific to a particular brand of 3D printers. You could try google for a forum specific to your printer brand and model. Printers usually come with software designed to convert files for them. I think stl is supported by most. 

Otherwise you could ask in the specific software forums for people using that software for printing. 

I know that Z-Brush will do what you're requiring and it exports to STL, VRML and OBJ. But you didn't list Z-Brush in your software so this info is likely irrelevant to you.