[vtkusers] Cropping, why is it limited to volumes?

[Jorrit Schaap]

Hi everybody,

Why is cropping limited to volumes?

For non-volumeMappers we can easily use 6 hardware clipping planes to
simulated cropping. It would be better however to filter the inputdata
of the mapper, such that only the cropped data is mapped to the screen.

My proposal is as follows:

- Copy the definition of the cropping functions (currently defined in
vtkVolumeMapper) one level up, so in vtkAbstractMapper3D
- Add cropping to the other mappers.

I think this isn't too much work, and it is a very useful feature to
have in any mapper.

Maybe someone has some ideas, or already has implemented something
similar. I would be happy to discuss this, and maybe help to devellop
it.

Best regards, Jorrit