[vtkusers] Hardware Clipping planes

[John Biddiscombe]

>leaving something like a hole in the geometry. To do that I currently
>use 6 mappers defining a clipping plane for each one (with the normal
>of each plane looking outwards). To avoid re-rendering parts that

Look at SetClippingPlanes in the existing mappers. You can define your 
planes as a vtkPlane collection (or implicit function) and then 
do->SetClippingPlanes().

I suspect it is exacly what you're after.

JB