[vtkusers] vtkInteractorStyleTrackballCamera zoom stops zooming?

[David Doria]

If I have a scene with an object far off in the distance, I can start
to zoom in by holding the right mouse button and moving the mouse up.
After I do this about 5 times, the object is still very small and I
want to continue zooming. However, this motion starts to change the
scene less and less with each stroke, eventually not doing anything
when I try to zoom. Is there a way around this?

Thanks,

David