[vtkusers] update confusion

[David Gobbi]

On Tue, 31 Oct 2000, Sebastien BARRE wrote:

> At 30/10/00 16:35, Sven wrote:
> 
> >How can I have the chain execute once for the whole volume independent
> >on what's on the screen?
> 
> if your object is named "reader", then :
>          reader UpdateWholeExtent
> will do the trick by reading the whole stuff in memory.
> if you use vtkImageReslice to display a slice from a volume, you do not 
> need that, but if you use two different vtkImageReslice (or objects) on the 
> same reader, then use UpdateWholeExtent once.

Whoa, not quite true.  If you use vtkImageReslice to display a slice from
the volume, you should still call 'reader UpdateWholeExtent.'  There are
some circumstances that cause vtkImageReslice to Update the whole extent
of its input, but usually it only Updates a portion of its input.

 - David

--
  David Gobbi, MSc                    dgobbi at irus.rri.on.ca
  Advanced Imaging Research Group
  Robarts Research Institute, University of Western Ontario