[vtkusers] Traversing vtkPolyData returns incorrect number of points

[David Edmunds]

Dear all,

I am traversing a vtkPolyData object which is read in from a file using vtkXMLPolyDataReader. I access the number of points in the vtkPolyData in two different ways, here is my source code:

  vtkSmartPointer<vtkXMLPolyDataReader> reader = vtkSmartPointer<vtkXMLPolyDataReader>::New();
  reader->SetFileName("/Users/dedmunds/Desktop/organ_Body.vtp");
  reader->Update();
  vtkSmartPointer<vtkPolyData> poly_data = reader->GetOutput();

  cout << "Number of points: " << poly_data->GetNumberOfPoints() << endl;

  int traversal_points = 0;
  for (int i=0; i<poly_data->GetNumberOfCells(); i++) {
    traversal_points += poly_data->GetCell(i)->GetNumberOfPoints();
  }
  cout << "Traversal number of points: " << traversal_points << endl;

Here is the output:

Number of points: 286402
Traversal number of points: 143204

Why do I get two different answers? The second number is approximately half the first. What am I doing wrong?

Thanks for your help,

Kind regards,

Dave 

The Institute of Cancer Research: Royal Cancer Hospital, a charitable Company Limited by Guarantee, Registered in England under Company No. 534147 with its Registered Office at 123 Old Brompton Road, London SW7 3RP.

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