[vtkusers] RequestInformation, RequestData and vtk filter, help needed

[Peter F Bradshaw]

Hi;

I forgot to mention this:

http://www.vtk.org/Wiki/images/8/80/Pipeline.pdf

On Sat, 20 May 2006, Peter F Bradshaw wrote:

> Hi Markus;
>
> Have you seen "Upgrading to and Understanding the New VTK Pipeline" at
> http://www.cmake.org/cgi-bin/viewcvs.cgi/Utilities/Upgrading/TheNewVTKPipeline.pdf?rev=1.5
>
> On Wed, 10 May 2006, Markus R wrote:
>
> > Hi,
> >
> > I am trying to write a filter in vtk (also to be imported in ParaView later). But I find the documentation not so good. I have a good idea what I need to do, but the functions RequestData, RequestInformation, RequestUpdateExtent, and a few others are confusing me. It seems to me these functions are automatically called for when you apply a filter in the pipeline, but in what order? And what code should they contain?
> >
> > I have looked at the already many existing filters for vtk (and also paraview) and sometimes they use RequestInformation, but not always. RequestData seems always be implemented. Well, I am indeed lost without documentation what these functions really should do, what code they should contain, and when I should use them.
> >
> > What I basically want to do for my filter is to take an unstructured grid as input, then perform my algorithm, and have as output an image. Could someone kind explain a few lines about the functions mentioned above, or link me to any documentation that explains their use and purpose?
> >
> > Regards, Markus
> >
>
> Cheers
>
>

Cheers

-- 
Peter F Bradshaw, http://www.exadios.com
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