%% 
%%  Ein Beispiel der DANTE-Edition
%% 
%% 
%%  Copyright (C) 2010 Herbert Voss
%% 
%%  It may be distributed and/or modified under the conditions
%%  of the LaTeX Project Public License, either version 1.3
%%  of this license or (at your option) any later version.
%% 
%%  See http://www.latex-project.org/lppl.txt for details.
%% 
%% 
%% ==== 
% Show page(s) 1
%% 
\documentclass[]{exaarticle}
\pagestyle{empty}
\setlength\textwidth{190.324pt}

\StartShownPreambleCommands
\usepackage{pst-solides3d}
\StopShownPreambleCommands
\begin{document}
\begin{pspicture}(-4,-5)(6,8)
\psset{lightsrc=viewpoint,viewpoint=50 60 30 rtp2xyz,Decran=60}
 \psSurface[ngrid=0.15 0.15,incolor=yellow,linewidth=0.2\pslinewidth,
 r = 2, fillcolor=cyan,
 axesboxed, Zmin=0,Zmax=4](-1,-2)(1,2){
  4 x dup mul mul y dup mul add dup 4 gt {pop 4} if }
\end{pspicture}
\end{document}