# PolygonalSurfaceContourLineInterpolator

VTKExamples/Cxx/PolyData/PolygonalSurfaceContourLineInterpolator

### Code

PolygonalSurfaceContourLineInterpolator.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>

    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkCellArray.h>
    #include <vtkImageDataGeometryFilter.h>
    #include <vtkPoints.h>
    #include <vtkPolyData.h>
    #include <vtkPolyDataCollection.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkSphereSource.h>
    #include <vtkTriangleFilter.h>
    #include <vtkXMLPolyDataReader.h>

    #include <vtkContourWidget.h>
    #include <vtkOrientedGlyphContourRepresentation.h>
    #include <vtkPolygonalSurfacePointPlacer.h>
    #include <vtkPolygonalSurfaceContourLineInterpolator.h>

    int main(int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> polyData;
      if (argc < 2)
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->SetThetaResolution(40);
        sphereSource->SetPhiResolution(20);
        sphereSource->Update();

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

      // The Dijkistra interpolator will not accept cells that aren't triangles
      vtkSmartPointer<vtkTriangleFilter> triangleFilter =
        vtkSmartPointer<vtkTriangleFilter>::New();
    #if VTK_MAJOR_VERSION <= 5
      triangleFilter->SetInput( polyData );
    #else
      triangleFilter->SetInputData( polyData );
    #endif
      triangleFilter->Update();

      vtkSmartPointer<vtkPolyData> pd = triangleFilter->GetOutput();

      //Create a mapper and actor
      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(triangleFilter->GetOutputPort());

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

      // Create the render window, renderer and interactor.

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> interactor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      interactor->SetRenderWindow(renderWindow);

      // Add the actors to the renderer, set the background and size

      renderer->AddActor(actor);
      renderer->SetBackground (.3, .4, .5);

      // Here comes the contour widget stuff...

      vtkSmartPointer<vtkContourWidget> contourWidget =
        vtkSmartPointer<vtkContourWidget>::New();
      contourWidget->SetInteractor(interactor);
      vtkSmartPointer<vtkOrientedGlyphContourRepresentation> rep =
        vtkOrientedGlyphContourRepresentation::SafeDownCast(
          contourWidget->GetRepresentation());
      rep->GetLinesProperty()->SetColor(1, 0.2, 0);
      rep->GetLinesProperty()->SetLineWidth(3.0);

      vtkSmartPointer<vtkPolygonalSurfacePointPlacer> pointPlacer =
        vtkSmartPointer<vtkPolygonalSurfacePointPlacer>::New();
      pointPlacer->AddProp(actor);
      pointPlacer->GetPolys()->AddItem( pd );
      rep->SetPointPlacer(pointPlacer);

      vtkSmartPointer<vtkPolygonalSurfaceContourLineInterpolator> interpolator =
        vtkSmartPointer<vtkPolygonalSurfaceContourLineInterpolator>::New();
      interpolator->GetPolys()->AddItem( pd );
      rep->SetLineInterpolator(interpolator);

      renderWindow->Render();
      interactor->Initialize();

      contourWidget->EnabledOn();

      interactor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(PolygonalSurfaceContourLineInterpolator)

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

    add_executable(PolygonalSurfaceContourLineInterpolator MACOSX_BUNDLE PolygonalSurfaceContourLineInterpolator.cxx )

    target_link_libraries(PolygonalSurfaceContourLineInterpolator ${VTK_LIBRARIES})

### Download and Build PolygonalSurfaceContourLineInterpolator

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

    cd PolygonalSurfaceContourLineInterpolator/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:

    ./PolygonalSurfaceContourLineInterpolator

WINDOWS USERS

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