VTK Volume Rendering

1. 이미지 데이터 객체 생성

vtkSmartPointer<vtkImageData> imageData = vtkSmartPointer<vtkImageData>::New();

2. 필터 생성

- 이미지 데이터를 변경할 필요가 없으면 굳이 생성하지 않아도 됨

3. 매퍼 생성 후 이미지 설정

vtkSmartPointer<vtkSmartVolumeMapper> volumeMapper = vtkSmartPointer<vtkSmartVolumeMapper>::New();

volumeMapper->SetBlendModeToComposite();

volumeMapper->SetInputData(imageData);

4. 속성 설정

vtkSmartPointer<vtkVolumeProperty> volumeProperty = vtkSmartPointer<vtkVolumeProperty>::New();

volumeProperty->ShadeOff();

volumeProperty->SetInterpolationType(VTK_LINEAR_INTERPOLATION);

4 - 1. 색상 설정

vtkColorTransferFunction colorTransfer = vtkSmartPointer<vtkColorTransferFunction>::New();

colorTransfer->AddRGBPoint(0.0, 0.0, 0.0, 1.0);

colorTransfer->AddRGBPoint(40.0, 1.0, 0.0, 0.0);

colorTransfer->AddRGBPoint(255.0, 1.0, 1.0, 1.0);

volumeProperty->SetColor(colorTransfer);

4 - 2. 투명도 설정

vtkPiecewiseFunction opacity = vtkSmartPointer<vtkPiecewiseFunction>::New();

opacity->AddPoint(0.0, 0.0);

opacity->AddPoint(80.0, 1.0);

opacity->AddPoint(80.1, 0.0);

opacity->AddPoint(255.0, 0.0);

volumeProperty->SetScalarOpacity(compositeOpacity);

5. Volume 생성 후 매퍼와 속성 설정

vtkSmartPointer<vtkVolume> volume = vtkSmartPointer<vtkVolume>::New();

volume->SetMapper(volumeMapper);

volume->SetProperty(volumeProperty);

6. 렌더러 생성 후 Volume 추가

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

renderer->SetBackground(0.8, 0.9, 0.5);

renderer->AddViewProp(volume);

renderer->ResetCamera();

7. 렌더 윈도우 생성 후 렌더러 추가

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

renderWindow->SetSize(500, 500);

renderWindow->AddRenderer(renderer);

renderWindow->Render();

8. 인터랙터 생성후 렌더윈도우 등록

vtkSmartPointer<vtkRenderWindowInteractor> interactor = vtkRenderWindowInteractor::New();

interactor->SetRenderWindow(renderWindow);

9. RayCast로 렌더링 

volumeMapper->SetRequestedRenderModeToRayCast();

renderWindow->Render();

10. 인터랙터 시작

interactor->Start();