[vtkusers] How to convert vtkImageMapper3D to poly data?

[Sophonet]

Hi all,

from VTK's clip cow example, I have seen that it is possible to 
intersect two poly data objects and retrieve the union etc for specific 
coloring. Is this also possible with images of type vtkImageMapper3D? I 
guess for that purpose I would have to convert vtkImageMapper3D somehow 
to a vtkPolyData object, but I am not sure how this is possible by 
keeping the texture information etc.

Any idea?

Thanks,

     Sophonet