[vtkusers] Accessing isosurface data

[Alex Benn]

Hi,
 
I've created a small program that takes two sets of 3D data, creates an
isosurface from one set, coloured by values from the second set (using
the vtkProbeFilter).
 
Once I have created the isosurface, I would like to read back in the
coordinates of all the surface's triangle vertices, and also the
respective mapped value from the second data set.
 
The first part I've managed OK - 
 
vtkPolyData *polys = isoProbe->GetPolyDataOutput();
       float numPolys = polys->GetNumberOfPolys();
 
       for(i=0;i<numPolys; i++)
       {
              polys->GetCell(i);
             vtkCell *cell = polys->GetCell(i);
             vtkPoints *points = cell->GetPoints();
             points->GetPoint(0, p1);
             ...
             ...
       }
 
but I am not quite sure how to get hold of the scalar values from the
second data set that are mapped onto the isosurface.
 
Any help much appreciated,
 
Alex.