[vtkusers] How to Recover vtkPolyData from vtkThreshold

[Mathieu Malaterre]

John Platt wrote:
> Hi Users,
> 
>  
> 
> I would like to render selective cells from vtkPolyData. I tried
> 
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> 
>             vtkPolyData > vtkThreshold > vtkPolyDataMapper
> 
>  
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> but this does not compile because the output of vtkThreshold is of type 
> vtkUnstructuredGrid.
> 
>  
> 
> Is there anyway of recovering the output of vtkThreshold as vtkPolyData 
> or an alternative filter?

You can use vtkDataSetMapper or vtkGeometryFilter to display a 
vtkUnstructuredGrid.

Otherwise if you know the types of elements you are using you can create 
your own vtkPolyData after the vtkThreshold (don't forget to call 
Update) and shallow copy all triangles/quad/strips/points...

HTH
Mathieu