[pstricks] tangent lines and positioning within pst-solides3d

[Jean-Paul Vignault]

Hi,

thanks for your image. I've put it there :
 
http://melusine.eu.org/lab/bpst/pst-solides3d/divers/directional_derivative.pst

 > 1. The command \psSurface has the option of drawing the curve that
 > results of intersecting a defined surface with a plane. Is it possible
 > to label such a curve for further use later on?

Not possible yet. But it's a good idea. Maybe in a future release ?

 > 2. Is there a direct way to plot the tangent line to the curve that
 > results of intersecting a defined surface with a plane?

[...]

no.

 > 3. How do we translate a line object? I tried for instance
 >
 > \psSolid[object=line,args=-0.5 -4 8.775 4.25 5.5
 > 8.775,linewidth=1.5pt,linestyle=dashed,linecolor=blue](a,b,c) to place
 > the line at the point (a,b,c) but it didn't work. However, it did work
 > with object=plan.

"line" object is not a real "solid type". It should be, but it missed
some time. It will be ok in the next release.

By waiting this future release, you can try with \codejps as here :
    http://melusine.eu.org/lab/bpst/pst-solides3d/divers/line_01.pst
where line L2 is the result of line L1 translation.

 > 4. Following the previous question, what is the center of an
 > object=plan? I translate such an object to a point (a,b,c) but I did
 > it more or less by trial and error.

I don't understand the question

 > 5. Finally, I tried to use linestyle=none as an option in the \psSolid
 > command for the object=plan, but it did not work.

ok.

Thanks for use pst-solides3d

Best regards,

Jean-Paul Vignault