[Paraview] Filter to keep points, dropping topology

[B.W.H. van Beest]

Hello,

I need a filter that only keeps the 3D points of a certain source (e.g.
coming from  an stl file).
The topology of the data set may go.

I thought that the following filter, only passing through the pointdata,
would do the job,
but that appears not to be the case (no points after the filter!)
What's going wrong and how should I change the filter?

Kind Regards,
Bertwim

================

int FilterPoints::RequestData( vtkInformation*,
                                             vtkInformationVector**
inputVector,
                                             vtkInformationVector*
outputVector)
{
   // Get the input and output data objects.
   vtkDataSet* input = vtkDataSet::GetData( inputVector[0] );
   vtkDataSet* output = vtkDataSet::GetData( outputVector );

   // output->CopyStructure( input );
   output->GetPointData()->PassData( input->GetPointData() );
  
   return 1;
}