[vtkusers] vtkTransformPolydataFilter ... how to get the transformed results

[Michael Jackson]

Wouldn't you want to do:
vtkPolyData* output = tpd->GetOutput();

as the output is just a raw pointer to a vtkPolyData object, which the  
filter owns. If you then wrap that point inside a vtkSmartPointer  
wouldn't you end up with 2 objects trying to free it(best case.)
___________________________________________________________
Mike Jackson                      www.bluequartz.net
Principal Software Engineer       mike.jackson at bluequartz.net
BlueQuartz Software               Dayton, Ohio


On Mar 11, 2010, at 8:51 AM, David Doria wrote:

> Hello everybody,
>
> I have a vtkLineSource object L1. I apply a transformation with the  
> vtkTransformPolyDataFilter tpd.
>
> so... as L1 is defined by 2 points, I have a transform TT which  
> defines the TransformPolyDataFilter.
> So I need to retrieve those 2 points but after the transform, so I  
> call:
>
> vtkSmartPointer<vtkLineSource> tmplineDir =  
> vtkLineSource::SafeDownCast(tpd->GetOutput());
>
> but the pointer it returns is NULL, causing of course a crash of the  
> software.
> what am I missing? :)
>
> Many thanks.
> Giancarlo
>
>
>
>
> You can't cast a polydata as a lineSource, which you are trying to  
> do with
> vtkLineSource::SafeDownCast(tpd->GetOutput());
>
> The output of tpd is a polydata, so you'd want to do
> vtkSmartPointer<vtkPolyData> output = tpd->GetOutput();
>
> ~David
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