draw3d, multiple plots, different colors



El mar, 06-12-2011 a las 15:43 -0800, Keith Derrick escribi?:
> I'm trying to plot a plane and an ellipsoid using draw3d and
> enhanced3d=true. Rather than use a single palette for both shapes, I'd
> like to plot each one using a different palette ... but on the same
> graph.

This is problematic. Gnuplot accepts only one palette at a time. But
with the extended syntax of enhanced3d you can work in different regions
of the color space.

Perhaps something like that:

draw3d(
    enhanced3d = [F(x,y),x,y],
    explicit(x^2+y^2,x,-1,1,y,-1,1),

    enhanced3d = [G(x,y),x,y],
    explicit(x^2-y^2+3,x,-1,1,y,-1,1)) $

where F and G map the plane R^2 on two non intersecting regions of R^1.

> 
> I can't see a way to do this. I'd also be happy with just a solid
> color for each one (probably need a little highlighting to get the 3D
> effect though).
> 

I suspect you would be happier with Vtk than with Gnuplot. Please, take
a look at

http://riotorto.users.sourceforge.net/vtk/paramsurf

Option 'palette' is global for the Gnuplot renderer and local for the
Vtk renderer; here you can play with different palettes in the same
graph.

Take into account that support for Vtk is 100% experimental and is not
documented.

--
Mario