vtk - VTK: 分割されたポリゴンを表示

Question

正二十面体を作成して細分化しました。表示しようとしているわけではありませんが、細分化されていない状態で表示されているようです。これが私のコードです：

vtkSmartPointer<vtkPlatonicSolidSource> icosahedron = vtkSmartPointer<vtkPlatonicSolidSource>::New();
     icosahedron->SetSolidTypeToIcosahedron();
     icosahedron->Update();

     cout << " Centre is " << icosahedron->GetOutput()->GetCenter()[0] << ", " << icosahedron->GetOutput()->GetCenter()[1] << ", " << icosahedron->GetOutput()->GetCenter()[2] << endl;
     cout << "    There are " << icosahedron->GetOutput()->GetNumberOfPolys() << " triangles." << endl;
     cout << " there are " << icosahedron->GetOutput()->GetNumberOfPoints() << " points " << endl;

     vtkSmartPointer<vtkPolyDataAlgorithm> subdivisionFilter;
     subdivisionFilter = vtkSmartPointer<vtkLinearSubdivisionFilter>::New();
     dynamic_cast<vtkLinearSubdivisionFilter *> (subdivisionFilter.GetPointer())->SetNumberOfSubdivisions(2);
     subdivisionFilter->SetInput(icosahedron->GetOutput());
     subdivisionFilter->Update();

     cout << " After " << endl;
     std::cout << "    There are " << subdivisionFilter->GetOutput()->GetNumberOfPoints() << " points." << std::endl;
     std::cout << "    There are " << subdivisionFilter->GetOutput()->GetNumberOfPolys() << " triangles." << std::endl;


     vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
     mapper->SetInputConnection(subdivisionFilter->GetOutputPort());

     vtkSmartPointer<vtkActor> actor = vtkSmartPointer<vtkActor>::New();
     actor->SetMapper(mapper);

     vtkSmartPointer<vtkRenderer> renderer =  vtkSmartPointer<vtkRenderer>::New();
     vtkSmartPointer<vtkRenderWindow> renderWindow = vtkSmartPointer<vtkRenderWindow>::New();

     renderWindow->AddRenderer(renderer);

     vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor = vtkSmartPointer<vtkRenderWindowInteractor>::New();
     renderWindowInteractor->SetRenderWindow(renderWindow);

     //Add the actors to the scene
     renderer->AddActor(actor);
     renderer->SetBackground(.1, .2, .3);

     //Render and interact
     renderWindow->Render();
     renderWindowInteractor->Start();

コンソール出力は次のとおりです。

 Centre is 0, 0, 0
    There are 20 triangles.
 there are 12 points 
 After 
    There are 162 points.
    There are 320 triangles.

確かに細分化されていることを確認。