I am interested in creating mathematical objects whose dimensions are known exactly. For example, suppose I would like to create a hollow dodecahedron with distance between parallel outside faces exactly 2cm? What would be the easiest, or most convenient software to create an STL file of this? Of course there is a learning curve associated with any piece of software, but setting this aside. I have downloaded Blender, and it seems a nightmare for creating exact models like this. It can create spheres and cylinders, that is no problem. But making them hollow is not simple. Lining everything up in a GUI does not seem optimal when you want faces to match perfectly. Also, when I use the "boolean union" and "boolean difference", half the time the mesh ends up with errors, even when using perfect cylinders and spheres. The lack of an "undo" button is pretty bad, too. I am not restricting myself to free software. One piece of software I have now is Mathematica. I noticed that it can export and import STL. Are there any tools in Mathematica for 3d modeling? Perhaps writing programs in Mathematica would be the easiest way to do all this. Anybody have any suggestions?