[VTK] Point normal, point color 예제.

vtkSmartPointer<vtkPolyDataNormals> normalGenerator = vtkSmartPointer<vtkPolyDataNormals>::New();
  normalGenerator->SetInput(src);
  normalGenerator->ComputePointNormalsOn();
  normalGenerator->ComputeCellNormalsOff();
  normalGenerator->Update();

 

// 노멀 데이터를 받아온다. http://www.vtk.org/Wiki/VTK/Examples/Cxx/PolyData/PolyDataExtractNormals 참고.
vtkFloatArray* normalDataFloat = vtkFloatArray::SafeDownCast(normalGenerator->GetOutput()->GetPointData()->GetArray("Normals"));

 

// Define some colors
  unsigned char red[3] = {255, 0, 0};
  unsigned char orange[3] = {255, 150, 0};
  unsigned char green[3] = {0, 255, 0};

 

// Setup the colors array
  vtkSmartPointer<vtkUnsignedCharArray> colors = vtkSmartPointer<vtkUnsignedCharArray>::New();
  colors->SetNumberOfComponents(3);
  colors->SetName("Colors");

 

 double viewNormal[3];
    render->GetActiveCamera()->GetViewPlaneNormal(viewNormal);

 

for(int k=0; k<numPts; k++)
  {
   if(normalDataFloat && ???)
   {     
    double polyNormal[3];
    normalDataFloat->GetTuple(k, polyNormal);
    
       if(viewNormal[0]*polyNormal[0]+viewNormal[1]*polyNormal[1]+viewNormal[2]*polyNormal[2] < 0.342) // 70도;
     colors->InsertNextTupleValue(orange);
    else
     colors->InsertNextTupleValue(green);
   }
   else{
    colors->InsertNextTupleValue(red);
   }
  }
  
  src->GetPointData()->SetScalars(colors);

 

...

뷰의 normal 값을 받아  각 포인트와 내적을 계산. 여러가지 컬러로 출력.