The SCALE3D procedure scales the 3D unit cube (a cube with the length of each side equal to 1) into the viewing area. Eight data points are created at the vertices of the 3D unit cube. The vertices are then transformed by the value of the system variable !P.T. The system is translated to bring the minimum ( x,y,z ) point to the origin, and then scaled to make each coordinate's maximum value equal to 1. The !P.T system variable is modified as a result.
This routine is written in the IDL language. Its source code can be found in the file
subdirectory of the IDL distribution.