[vtkusers] draw labelled 3D particles interface

[Henry Proudhon]

Hi everyone,

I've been using vtk for a few months now with some succes and really
like it. But since a few days now, I'm stuck with one of my problems.

I've a volume say 100x100x100 voxels with 8 bits data being the label of
the particles. Imagine you have a dozen of particles and they fill
completely the space (like with a tesselation of the space).

I'd like to draw the surface of the interface of the particles.
vtkContourFilter dose not seem to be appropriate, so I tried to work out
the mangnitude of the gradient and use a contour filter on the
magnitude. This worked to some extend but I get a nice description of
the interior of the particles but not the actual interface. The same
with a threshold.

Anybody have an idea?
Thank a lot for any clue :)
Henry