[vtkusers] Subtracting polydata from polydata?

[jarv0075]

I'm currently trying to compare two rendered surfaces based on the same
input MRI data to see what the differences are between the two.

I can think of a few ways to do this, but what would be the 'preferred'
method?  I'm thinking some way of subtracting one dataset from another
(leaving the rendered difference between the two)?  

If anyone has done something similar, what are some other meaningful
visualization techniques to show the difference between two surfaces?



Thanks,



-Tim