\documentclass{article}
\usepackage{pst-solides3d}
\makeatletter
\def\lightsource{
\pstVerb{\pst@solides@viewpoint
/PhI exch def /ThetA exch def /Dist exch def
/Lx Dist ThetA cos mul PhI cos mul def
/Ly Dist ThetA sin mul PhI cos mul def
/Lz Dist PhI sin mul def}%
\psset{lightsrc=Lx Ly Lz}
}
\makeatother
\begin{document}
\pagestyle{empty}

\begin{center}
% fabrique du bi-cone
%\codejps{
%-5 3 0 [18 60] newcone
% 5 3 0 [18 60] newcone
% dup solidfacesreverse
% solidfuz
%(bicone) writesolidfile
% }
\begin{pspicture}(-5,-6)(8,7)
\psset{SphericalCoor=true,viewpoint=50 -30 20,Decran=50}
\lightsource
\psframe[fillstyle=solid,fillcolor=gray!50](-5,-6)(8,7)%
\psSolid[object=grille,base=-4 4 -4 8,linecolor={[rgb]{0.72 0.72 0.5}}](0,0,-5)
\codejps{
solidlightOn
/solidgrid false def
(bicone) readsolidfile
/monplan [20 cos 0 20 sin -0.25] eq2plan def
/monplan2 
   [20 cos 0 20 sin -0.25] eq2plan 
   dup 0 0 90 rotateOplan
   dup 0 5 0 plantranslate
def
% monplan solidplansepare
%exch
%{0 0 90 rotateOpoint3d} solidtransform
%{0 5 0 translatepoint3d} solidtransform
%(biconeplanincline-part0) writesolidfile
%(biconeplanincline-part1) writesolidfile
(biconeplanincline-part0) readsolidfile
dup  (0.7 1 0.7 setrgbcolor) outputcolors
dup 0 (0.72 0.72 0.5 setrgbcolor) solidputfcolor
dup 1 (0.72 0.72 0.5 setrgbcolor) solidputfcolor
dup drawsolid**
/solidintersectiontype 0 def
/solidintersectionplan [monplan2] def
/solidintersectionlinewidth [2] def
/solidintersectioncolor [(bleu)] def
/aretescachees false def
0 setlinewidth
drawsolid
%
%
(biconeplanincline-part1) readsolidfile
dup  (0.7 1 0.7 setrgbcolor) outputcolors
dup 0 (0.72 0.72 0.5 setrgbcolor) solidputfcolor
dup 1 (0.72 0.72 0.5 setrgbcolor) solidputfcolor
dup drawsolid**
/solidintersectiontype 0 def
/solidintersectionplan [monplan] def
/solidintersectionlinewidth [2] def
/solidintersectioncolor [(rouge)] def
/aretescachees false def
0 setlinewidth
drawsolid
}
\psSolid[object=plan,action=draw,
   definition=equation,
   args={[20 cos 0 20 sin -0.25] 90},
   base=-3 3 -6 5,planmarks,showBase]
\psSolid[object=plan,action=draw,
%   visibility=false,
   definition=equation,RotZ=90,
   args={[20 cos neg 0 20 sin neg 0.25] 90},
   base=-3 3 -6 5,planmarks,showBase](0,5,0)
\axesIIID[linecolor=blue](0,0,0)(4,3,6)
\end{pspicture}
\end{center}

\end{document}