STL (STereoLithography) is a file format native to the stereolithography CAD software created by 3D Systems. STL files describe only the surface geometry of a three dimensional object without any representation of color, texture or other common CAD model attributes. More about STL file format: http://en.wikipedia.org/wiki/STL_(file_format) .
I just retype the document "Generate STL" in Mathcad 15, the original of which was created for Mathcad Prime 2 version (http://communities.ptc.com/docs/DOC-3618).
