[vtkusers] vtkExtractVOI and transforms

[John Clyne]

Hi, I seem to be having some trouble with the vtk3.2 version of
vtkExtractVOI. I'm using it to extract a subregion from a structured
points data set, the results of which are fed to both a vtkVolumeMapper
and a vtkOutlineFilter. The problem occurs when I apply user
transformations to either of these objects. The coordinate origin does
not appear to be in the same location as if I had simply created a
volume of the desired resolution. Furthermore, the coordinate origin
appears to be different for both the outline and volume. I.e. when I
apply the same user transform rotation to both of these object the
rotate differently, neither one about the point I would expect (i'm not
sure what point they are rotating about).

Any pointers would be greatly appreciated.

Thanks!


John Clyne      (clyne at ncar.ucar.edu)
National Center for Atmospheric Research
P.O. Box 3000, Boulder, Colorado 80307
(303) 497-1236  FAX (303) 497-1298