[vtkusers] vtkExtractSelectedFrustum introduces duplicate nodes

[David E DeMarle]

Hello,

I am not sure why that would happen either, especially because you've
set PassThroughOn (more recent versions of VTK call that
PreserveTopology). That flag tells the ExtractSelectedFrustumFilter to
shallow copy the geometry and topology of its input to its output.
With that on, the only difference in the output of this filter from
its input should be the addition of two new arrays which mark each
cell and point as either inside or outside the frustum.

I am curious what is happening to produce this->PreviouslyExtractedSubset.

If the input looks OK and the duplication happens when
PreserveTopology is off, I would suspect that something is going wrong
in the filter when it uses the pointMap array to identify which input
points it has visited and what indexes they have in the output.

cheers,
Dave DeMarle




On Fri, Apr 11, 2008 at 4:38 PM,  <kshivann at engineering.uiowa.edu> wrote:
> hi all,
>    i am using vtkExtractSelectedFrustum to select portion of a mesh. The
> extracted mesh has duplicate nodes. The piece of code is as follows
>
>         vtkExtractSelectedFrustum *Extract =
> vtkExtractSelectedFrustum::New();
>         Extract->SetInput(this->PreviousSelectedSubset);
>         Extract->PassThroughOn();
>         Extract->SetFrustum(AreaPicker->GetFrustum());
>         Extract->Update();
>
>  I am not sure why would the filter introduce duplicate nodes.
>
>  thanks
>
>  Kiran
>
>
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