\DocumentMetadata{lang=en}%
%****** ex_22.tex ******
%\PassOptionsToPackage{dvipsnames}{xcolor}%
\documentclass[pstricks,border=5mm]{standalone}
\usepackage{pst-solides3d}%
\begin{document} 
\psset{unit=1.5,viewpoint=50 -20 30 rtp2xyz,Decran=50}%
\begin{pspicture}[showgrid=false](-2,-2)(1.5,2)
\codejps{
/tet {
  2 newtetraedre
  dup 0.8 solidaffine
  dup videsolid
  dup (yellow) outputcolors
  dup (red) inputcolors
} def
tet drawsolid**
}
\end{pspicture}
\end{document}