ex_12.tex

\documentclass[a4paper]{article}
\usepackage{pst-solides3d}
\pagestyle{empty}
\begin{document}
 
%@AUTEUR: Juergen Gilg
% \section*{Twister \dots}
\psset[pst-solides3d]{viewpoint=10 9 12,SphericalCoor,
	Decran=40,lightsrc=15 5 10}
\begin{pspicture}(-6,-11)(-6,7)
\rput(0,0){
\defFunction[algebraic]{klein}(u,v){u*cos(v)}%
{Euler^(-u*u)*(sin(2*pi*u) - u*cos(3*v))}%
{u*sin(v)}
\psSolid[object=surfaceparametree,
    base=0 2 0 pi 2 mul,
    linecolor={[cmyk]{1,0,1,0.5}},linewidth=0.75\pslinewidth,
    incolor=green,
    fillcolor=green,
    ngrid=50,
    RotY=225,
    RotX=-90,
    function=klein]%
}
\end{pspicture}
 
\end{document}