\documentclass{article} \usepackage{pst-solides3d} \begin{document} \pagestyle{empty} \begin{center} \begin{pspicture*}(-6,-6)(6,6) \psset{solidmemory} \psset{lightsrc=viewpoint,viewpoint=40 -60 15,Decran=60,opacity=.7} \defFunction{G}(t) {t Cos t Cos mul 3 mul} {t Cos t Sin mul 3 mul} {t Sin 3 mul} \defFunction{G'}(t) {t Cos t Sin mul -6 mul} {t 2 mul Sin -2 mul} {t Cos 3 mul} \psSolid[object=cone, function=G, range=-6.28 0, ngrid=10 100, origine=-3 0 0, action=none, name=C1, ] \psSolid[object=courbe, function=G, r=0.05, range=-6.28 0, ngrid=300 8, name=C2, fillcolor=blue, action=none ] \psSolid[object=fusion, linewidth=.01, base=C1 C2, ] \composeSolid \end{pspicture*} \end{center} \end{document}