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

[Berk Geveci]

That's not good. You should not set WHOLE_EXTENT() in RequestData().
Set it to VOI in RequestInformation(). Otherwise, you will run into
problems sooner or later.

-berk

On 2/12/08, Mike Jackson <imikejackson at gmail.com> wrote:
> VOI is what the user wants to see.
>
> in RequestInformation we have:
> outInfo->Set( vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), this-
>  >DataExtent, 6 );
>
> where this->DataExtent is the entire 7000 x 8000 x 200 image size.
>
> Then in RequestData() we have the following:
>
> outInfo->Set(vtkStreamingDemandDrivenPipeline::WHOLE_EXTENT(), this-
>  >VOI, 6);
>
>
> Does that help?
> mike
>
>
> On Feb 12, 2008, at 4:50 PM, Berk Geveci wrote:
>
> > 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
> >>>>
> >>
>
>