[Paraview] What part of the pipeline is producing the request for UPDATE_EXTENT?

[Berk Geveci]

Is the VOI a parameter of the reader? Are you setting the WHOLE_EXTENT() to VOI?

On 2/12/08, Mike Jackson <imikejackson at gmail.com> wrote:
> So I think I finally have this working.
>
> In Request Information() I gather the actual full size extents of the
> data set (7000 x 8000 x 200). In the RequestData() method I get what
> the user actually wants (VOI), create a new vtkImageData based on VOI
> information, load the data into the new vtkImageObject, then do an
> output->ShallowCopy(image); just before the return of the RequestData
> Method. Do you see any drawbacks to using this type of approach?
>
> This seems to work as the RequestData() method is only executing once
> now.
>
> The next thing I have to figure out is how to get some labels that
> tell the user just how large their data set it. Probably have to go
> with a Plugin with a custom Qt Panel at this point as I don't see any
> other way of doing it.
>
> In PV 2.6 there used to be ways to get read only properties from a
> custom filter class and present those to the user. Doesn't seem like
> those facilities are there any more with PV 3.x
>
> Thanks for the heads up.
> Mike Jackson
>
> On Feb 12, 2008, at 12:03 PM, Berk Geveci wrote:
>
> > No. UPDATE_EXTENT() is set on the input information during
> > RequestUpdateExtent(). A reader should NOT set UPDATE_EXTENT(). A
> > reader should set WHOLE_EXTENT() in RequestInformation().
> >
> > -berk
> >
> >
> > On 2/12/08, Mike Jackson <imikejackson at gmail.com> wrote:
> >> I was under the impression that I needed to set the UPDATE_EXTENT
> >> like the following in my RequestInformation() method:
> >>
> >> outInfo->Set( vtkStreamingDemandDrivenPipeline::UPDATE_EXTENT(),
> >> this-
> >>> DataExtent, 6 );
> >>
> >> but I think that is a bad assumption for a reader. Is the ParaView
> >> pipeline actually setting the UPDATE_EXTENT based on what it needs to
> >> render?
> >>
> >>
> >> --
> >> Mike Jackson
> >> imikejackson & gmail * com
> >>
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