[vtk-developers] Correct handling of information propagation

[John Biddiscombe (CSCS)]

In the old pipeline, we had vtkStructuredPointsSource, which was 
interesting in that it didn't necessarily compute the correct 
information (regarding extents).
I would like to implement a filter which takes points as input, but 
produces an imagedata as output similar to ShepardMethod, except that 
vtkShepardMethod uses a fixed extent, which is set by the user (so the 
information output can simply set its whole extent without issue)

Suppose my Image that is produced as output, depends upon the extents of 
the polygons passed in (the bigger the polys, then perhaps the larger 
the wholeextent of the output).

In the UpdateInformation method, I used to do an Update on the input (or 
inputs), get the relevent info from them, then compute a whole extent, 
then make that visible to the output...

Can anyone tell me the correct way to handle this in the new pipeline 
(inside RequestInformation). Is there an example of this I can look at 
anywhere?

thanks

JB

-- 
John Biddiscombe,                            email:biddisco @ cscs.ch
http://www.cscs.ch/about/BJohn.php
CSCS, Swiss National Supercomputing Centre  | Tel:  +41 (91) 610.82.07
Via Cantonale, 6928 Manno, Switzerland      | Fax:  +41 (91) 610.82.82