# Silhouette

VTKExamples/Cxx/PolyData/Silhouette

### Code

Silhouette.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkProperty.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkPolyDataSilhouette.h>
    #include <vtkSphereSource.h>
    #include <vtkXMLPolyDataReader.h>
    #include <vtkCleanPolyData.h>

    int main(int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> polyData;
      if (argc < 2)
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->Update();

        polyData = sphereSource->GetOutput();
      }
      else
      {
        vtkSmartPointer<vtkXMLPolyDataReader> reader =
          vtkSmartPointer<vtkXMLPolyDataReader>::New();
        reader->SetFileName(argv[1]);

        vtkSmartPointer<vtkCleanPolyData> clean =
          vtkSmartPointer<vtkCleanPolyData>::New();
        clean->SetInputConnection(reader->GetOutputPort());
        clean->Update();

        polyData = clean->GetOutput();
      }

      //create mapper and actor for original model
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
    #if VTK_MAJOR_VERSION <= 5
      mapper->SetInput(polyData);
    #else
      mapper->SetInputData(polyData);
    #endif

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

      //create renderer and renderWindow
      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      renderer->AddActor(actor); //view the original model

      //Compute the silhouette
      vtkSmartPointer<vtkPolyDataSilhouette> silhouette =
        vtkSmartPointer<vtkPolyDataSilhouette>::New();
    #if VTK_MAJOR_VERSION <= 5
      silhouette->SetInput(polyData);
    #else
      silhouette->SetInputData(polyData);
    #endif
      silhouette->SetCamera(renderer->GetActiveCamera());
      silhouette->SetEnableFeatureAngle(0);

      //create mapper and actor for silouette
      vtkSmartPointer<vtkPolyDataMapper> mapper2 =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper2->SetInputConnection(silhouette->GetOutputPort());

      vtkSmartPointer<vtkActor> actor2 =
        vtkSmartPointer<vtkActor>::New();
      actor2->SetMapper(mapper2);
      actor2->GetProperty()->SetColor(1.0, 0.3882, 0.2784); // tomato
      actor2->GetProperty()->SetLineWidth(5);
      renderer->AddActor(actor2);
      renderer->SetBackground(.1, .2, .3);
      renderer->ResetCamera();

      //you MUST NOT call renderWindow->Render() before
      //iren->SetRenderWindow(renderWindow);
      vtkSmartPointer<vtkRenderWindowInteractor> iren =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      iren->SetRenderWindow(renderWindow);

      //render and interact
      renderWindow->Render();
      iren->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(Silhouette)

    find_package(VTK REQUIRED)
    include(${VTK_USE_FILE})

    add_executable(Silhouette MACOSX_BUNDLE Silhouette.cxx)

    target_link_libraries(Silhouette ${VTK_LIBRARIES})

### Download and Build Silhouette

Click here to download Silhouette and its CMakeLists.txt file. Once the tarball Silhouette.tar has been downloaded and extracted,

    cd Silhouette/build

If VTK is installed:

    cmake ..

If VTK is not installed but compiled on your system, you will need to specify the path to your VTK build:

    cmake -DVTK_DIR:PATH=/home/me/vtk_build ..

Build the project:

    make

and run it:

    ./Silhouette

WINDOWS USERS PLEASE NOTE: Be sure to add the VTK bin directory to your path. This will resolve the VTK dll's at run time.