%@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 30,lightsrc=25 37 17,Decran=50,unit=0.75} \begin{center} \def\voc{% \pstVerb{ /torsion { 2 dict begin /M defpoint3d % on r\'{e}cup\`{e}re les coordonn\'{e}es /AngleTorsion M \ai\space mul neg 3 -2 roll pop pop def M 0 0 AngleTorsion rotateOpoint3d end} def }% \defFunction{F}(t){t cos 5 mul}{t sin 5 mul}{} \defFunction{G}(t){t 36 add cos 3 mul}{t 36 add sin 3 mul}{} \rput(0,0){\psSolid[% object=ruban, h=7.5, fillcolor=gray, incolor=lightgray, base=0 72 360 {/Angle exch def Angle F Angle G} for, transform=torsion, ngrid=12 ](0,0,0) } } \FPdiv{\myDeltaA}{6}{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{center} \end{document}