%!

/page-begin {
  gsave
  /S 72 def
  S dup scale
  1 S div setlinewidth
  4 5 translate
} def

/page-end {
  grestore
  showpage
} def

(ps3d.inc) run

/y 2 2 sqrt mul 3 div def
/z -1 3 div def
% exaggerate perspective:
[ 0 0 2 1 ] set-eye
/dA 10 def

% to eliminate redundant yping:
/tv [ % for Tetrahedron-Vertex
  [ 0 0 1 ]
  [ 0 y z ] 
  [ y 3 sqrt 2 div neg y 2 div neg z ]
  [ y 3 sqrt 2 div     y 2 div neg z ]
] def

100 {
  page-begin
  newpath
  % top edges
  tv 0 get aload pop moveto3d
  tv 1 get aload pop lineto3d
  tv 0 get aload pop moveto3d
  tv 2 get aload pop lineto3d
  tv 0 get aload pop moveto3d
  tv 3 get aload pop lineto3d
  % bottom
  tv 1 get aload pop moveto3d
  tv 2 get aload pop lineto3d
  tv 3 get aload pop lineto3d
  tv 1 get aload pop lineto3d
  stroke
  page-end
  % rotate around the x-axis
  [ 1 0 0 ] dA rotate3d
} repeat