[vtkusers] vtkContourWidget -- how to display 'off-plane' contours?

[kent williams]

As long as I'm asking hard questions, consider this scenario.

My application maintains 3 orthogonal views of the same volume:
Sagittal, Axial, Coronal.

The advantage of using VTK is not having to write all the code that's
already in VTK.  The disadvantage is that if you want to do something
not currently done in VTK, you have to crack open a bunch of 'black
boxes' and monkey around with the spaghetti wiring inside.

Our old tracing application let you trace on one view (e.g. Sagittal),
and in the other 2 views, it displayed the intersection of all the
traced contours with the image plane of those other two views.

So I'm in the unenviable position of cracking open the
vtkContourRepresentation, and somehow finding the intersection of the
contour and the plane of an orthoganal view, and then show the
intersection.

So I guess my question is this: How would I do this the VTK way?