anim.tex

%@AUTEUR: Juergen Gilg
\documentclass{article}
\usepackage[dvipsnames,svgnames]{pstricks}
\usepackage{pst-node,pst-plot,pst-eucl}
\usepackage{graphicx}
\usepackage{pst-solides3d}
\usepackage{multido}
\usepackage[nomessages]{fp}
\pagestyle{empty}
\begin{document}
\psset{SphericalCoor,viewpoint=50 50 20,lightsrc=25 37 17,Decran=50,unit=0.75}
\def\voc{%
\pstVerb{
 /torsion {
2 dict begin
/M defpoint3d % on récupère les coordonnées
/AngleTorsion M \ai\space mul 3 -2 roll pop pop def
M 0 0 AngleTorsion rotateOpoint3d
end} def
}%
 
\rput(0,0){\psSolid[object=prisme,h=8,ngrid=20 6,
 base=1.5 0 1.5 1.5 0 1.5 -1.5 1.5 -1.5 0 -1.5 -1.5 0 -1.5 1.5 -1.5,
 transform=torsion,
 fillcolor=lightgray,
 incolor=lightgray,
% hollow,
% opacity=0.6
](0,0,0)}%
}
 
\FPdiv{\myDeltaA}{20}{60}%
\def\ai{0}%
\FPdiv{\myDeltaB}{0.95}{90}%
\def\bi{0.5}%
 
\multido{\i=1+1}{60}{
 \begin{pspicture}(-4,0)(4,9)
  \voc%
 \end{pspicture}
 \newpage
 \FPadd{\ai}{\ai}{\myDeltaA}
 \FPadd{\bi}{\bi}{\myDeltaB}
}
 
\end{document}