[pstricks] projections onto different planes in one picture

[Herbert Voss]

Am 30.08.2010 15:43, schrieb Zbigniew Nitecki:
> Thanks, Herbert.
> I hope that my inclusion of the picture doesn't make this too large to post (I 
> am not so adept at posting a picture on my web page).
> 
> This eliminates the \psset{plan=??}, and (after some fiddling) I managed to get 
> the two planes intersecting properly. However, while the first projected curve 
> (blue) shows up fine, the second (red) does not. This is true even if I comment 
> out all references to the first (blue) plane and the curve on it. I thought that 
> maybe it was projecting on the "back side" of the red plane, but it fails to 
> appear whether I rotate it 180 degrees or not.

do not use opacity=0, use a value > 0 or didn't use the option.
0 means totally transparent, which is the same as not seen.

However, I do not really understand, why changing the
order of the two planes helped. It was more a trial and error
methode to find a working example than understanding the
problem ...

\documentclass[11pt]{article}
\usepackage{pst-solides3d}

\begin{document}
\begin{pspicture}(-3,-1.5)(3,5.5)
\psset{unit=0.35,lightsrc=40 50 50,viewpoint=18 65 30 rtp2xyz,solidmemory}
\psSolid[object=plan,
definition=equation,
args={[1 0 0 0] 90},
base=-2 2 -0.5 4.5,
fillcolor=blue!10,
name=xplane,
ngrid=10 10,
action=none
]
\psSolid[object=plan,
definition=equation,
args={[0 1 0 0] 180},
base=-2 2 -0.5 4.5,
fillcolor=red!10,
name=yplane,
ngrid=10 10,
action=none
]
\psSolid[object=fusion,
base=xplane_s yplane_s,
]
\composeSolid%
%
\psSolid[object=plan,
definition=equation,
args={[0 1 0 0] 180},
base=-2 2 -0.5 4.5,
name=yplane,
linewidth=0.5pt,
ngrid=10 10,
action=none,
]
\psSolid[object=plan,
definition=equation,
args={[1 0 0 0] 90},
base=-2 2 -0.5 4.5,
name=xplane,
ngrid=10 10,
action=none,
]
\defFunction[algebraic]{xcutfcn}(y){y*y}{}{}%
\psProjection[object=courbe,
linecolor=blue,
linewidth=2pt,
plan=xplane,
range=0 2,
resolution=720,
function=xcutfcn,
action=draw**,
]
\defFunction[algebraic]{ycutfcn}(x){4*x*x}{}{}%
\psProjection[object=courbe,
linecolor=red,
linewidth=2pt,
plan=yplane,
range=-1 0,
resolution=720,
function=ycutfcn,
action=draw**,
]
\end{pspicture}

\end{document}


Herbert