animation-helice.tex

\documentclass{article}
\usepackage{pst-solides3d}
% Jean-Paul Vignault
% Manuel Luque
\pagestyle{empty}
\begin{document}
\psset{lightsrc=75 -63 17,SphericalCoor=true,viewpoint=100 -45 10,Decran=50,fontsize=50}
\multido{\iRotZ=0+10}{36}{
\begin{center}
\begin{pspicture*}(-5,-3)(5,4)
\psframe(-5,-3)(5,4)
\pstVerb{/iRotZ \iRotZ\space def}%
\psSolid[object=grille,base=-7 7 -7 7,ngrid=1. 1.,action=draw,linecolor=red](0,0,-3.4)
\defFunction[algebraic]{helix}(u,v)%
  {2*(0.4*cos(v)-1)*cos(u)}
  {2*(0.4*cos(v)-1)*sin(u)}
  {0.4*sin(v)+0.3*u}
\codejps{
/helice
   -10 10 0 6.28 [60 0.4] {helix} newsurfaceparametree
   {0 0 iRotZ rotateOpoint3d} solidtransform
   {0 -4 0 translatepoint3d} solidtransform
   dup solidfacesreverse
def
/helicesym
   helice dupsolid exch pop
   {[0 1 0 0] symplan3d} solidtransform
   dup solidfacesreverse
def
/solidgrid false def
solidlightOn
helicesym dup [0 1 0.5 1] solidputhuecolors dup (White) inputcolors
drawsolid**
.5 setfillopacity
[0 1 0 0] eq2plan
dup [-7 7 -5 3.4] planputrange
dup [14. 8.4] planputngrid
newplan
dup videsolid
dup (0.7 0.7 1 setrgbcolor) (0.7 0.7 1 setrgbcolor) inoutputcolors
drawsolid**
helice dup [0 1 0.5 1] solidputhuecolors dup (White) inputcolors
drawsolid**
}
\end{pspicture*}
\end{center}\newpage}
\end{document}