On Thu, Sep 29, 2011 at 4:31 PM, Holger Brandsmeier <holger.brandsmeier@sam.math.ethz.ch> wrote:
Hi Ben,

in your example
> http://matplotlib.sourceforge.net/examples/mplot3d/polys3d_demo.html
the essential line is:
 ax.add_collection3d(poly, zs=zs, zdir='y')
according to everything I see this can only draw something that is
made out of several axes parallel parts. I don't think how with such a
command you could end up with some picture like:
 http://matplotlib.sourceforge.net/plot_directive/mpl_examples/mplot3d/surface3d_demo.hires.png

That is correct.  It is only for simple conversions.
 

What I want to plot should look like that picture (with is part of
your gallery), just that I don't have a meshgrid data underlying.


That is why you have to work with the 3D objects from mpl_toolkits.mplot3d.art3d directly.  There isn't a lot of documentation, so your best bet is to look at the source code of the module.
 
Your second example seems to have the same limitation
 http://matplotlib.sourceforge.net/examples/mplot3d/pathpatch3d_demo.html
just it works with the command
 art3d.pathpatch_2d_to_3d(p, z=0, zdir="x")

The only way that I currently see is that I call
 ax.plot_surface()
for each quadrilateral of my mesh.


That would be overkill.  However, try checking out the source code for plot_surface() to see how it creates its Poly3DCollection object.

Ben Root