[pstricks] Intersection of three planes

Olivier Vogel vogel.olivier at gmail.com
Tue Apr 28 19:25:21 CEST 2020

Hello everyone,

I'm trying to represent the intersection of three planes. Here is my code:

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\documentclass{article}
\usepackage{pst-solides3d}
\begin{document}
\begin{pspicture}(-1.5,-1.5)(1.5,1.5)%
\psset{solidmemory,unit=.75cm,algebraic,viewpoint=40 30 20}%
\defFunction{planun}(u,v){u}{v}{0}%
\psSolid[object=surfaceparametree,base=-2 2 -2
2,fillcolor=yellow,function=planun,ngrid=6,action=none,name=A1](0,0,0)%
\defFunction{plandeux}(u,v){u}{v}{-v}%
\psSolid[object=surfaceparametree,base=-2 2 2 sqrt neg 2
sqrt,fillcolor=green,function=plandeux,ngrid=6,action=none,name=A2](0,0,0)%
\defFunction{plantrois}(u,v){u}{v}{-u}%
\psSolid[object=surfaceparametree,base=2 sqrt neg 2 sqrt -2
2,fillcolor=red,function=plantrois,ngrid=6,action=none,name=A3](0,0,0)%
\psSolid[object=fusion,base=A1 A2 A3,linecolor=gray,action=draw**](0,0,0)%
\composeSolid%
\psPoint(0,0,0){O}\psdot(O)%
\end{pspicture}%
\end{document}

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I can't figure out how to achieve both these conditions at the same time:

1) exactly the same grid (ngrid=6)
2) a much more precise intersection (easy to get it with ngrid=100),
but with only the few 6 six lines drawn.

Is it possible?