Nice. One thing you can aim at for the future is to show the atomic and/or molecular hybrid orbitals in 3d, which is difficult for students to picture. ----- $ Runsun Pan, PhD $ libs: doctest , faces ( git ), offline doc ( git ),runscad.py( 1 , 2 , git ); $ tips: hash( 1 , 2 ), sweep , var , lerp , animGif -- View this message in context: http://forum.openscad.org/Using-a-single-parameter-to-set-multiple-variables-tp14102p14106.html Sent from the OpenSCAD mailing list archive at Nabble.com.