\documentclass{article} \usepackage{pst-solides3d} \begin{document} \pagestyle{empty} \begin{pspicture*}(-6,-6)(6,6) \psset{solidmemory} \psset{lightsrc=viewpoint,viewpoint=10 -10 5,Decran=60,opacity=.7} \defFunction{G}(t) {3 t mul Sin} {t 2 mul Cos} {t Cos} \defFunction{G'}(t) {3 t mul Cos 3 mul} {t 2 mul Sin -2 mul} {t Sin neg} \psSolid[object=cone, function=G, range=-6.28 0, ngrid=10 100, origine=0 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{document}