Loop subdivision algorithm for an input OBJ. the output is a subdivide mesh

subdivide.cpp

// Just for testing, a Loop subdivision algorithm to the input OBJ
// the output is the subdivide mesh
vtkSmartPointer<vtkPolyData> Subdivide(vtkSmartPointer<vtkPolyData> reader)
{
  // Subdivision filters only work on triangles
  vtkSmartPointer<vtkTriangleFilter> triangles = vtkSmartPointer<vtkTriangleFilter>::New();
  triangles->SetInputData(reader);
  triangles->Update();
  vtkSmartPointer<vtkPolyData> originalMesh = triangles->GetOutput();  // this is the original mesh actually

  vtkSmartPointer<vtkPolyDataAlgorithm> subdivisionFilter = vtkSmartPointer<vtkLoopSubdivisionFilter >::New();
  dynamic_cast<vtkLoopSubdivisionFilter *> (subdivisionFilter.GetPointer())->SetNumberOfSubdivisions(2);
  subdivisionFilter->SetInputData(originalMesh);
  subdivisionFilter->Update();

  return subdivisionFilter->GetOutput();
}