# ShrinkPolyData

VTKExamples/Cxx/PolyData/ShrinkPolyData

Other Languages

See (CSharp)

### Code

ShrinkPolyData.cxx

    #include <vtkSmartPointer.h>

    #include <vtkShrinkPolyData.h>
    #include <vtkSphereSource.h>

    #include <vtkPolyData.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkCamera.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkXMLPolyDataReader.h>

    #include <vtkNamedColors.h>

    int main(int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> inputPolyData;
      if(argc > 1)
      {
        vtkSmartPointer<vtkXMLPolyDataReader> reader =
          vtkSmartPointer<vtkXMLPolyDataReader>::New();
        reader->SetFileName(argv[1]);
        reader->Update();
        inputPolyData = reader->GetOutput();
      }
      else
      {
        vtkSmartPointer<vtkSphereSource> sphereSource =
          vtkSmartPointer<vtkSphereSource>::New();
        sphereSource->SetPhiResolution(15);
        sphereSource->SetThetaResolution(15);
        sphereSource->Update();
        inputPolyData = sphereSource->GetOutput();
      }

      vtkSmartPointer<vtkNamedColors> colors =
        vtkSmartPointer<vtkNamedColors>::New();

      vtkSmartPointer<vtkShrinkPolyData> shrink =
        vtkSmartPointer<vtkShrinkPolyData>::New();
      shrink->SetShrinkFactor(.8);
      shrink->SetInputData(inputPolyData);

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

      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      vtkSmartPointer<vtkRenderWindowInteractor> interactor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      interactor->SetRenderWindow(renderWindow);

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(shrink->GetOutputPort());
      mapper->ScalarVisibilityOff();

      vtkSmartPointer<vtkProperty> back =
        vtkSmartPointer<vtkProperty>::New();
      back->SetColor(colors->GetColor3d("Peacock").GetData());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->SetColor(colors->GetColor3d("Salmon").GetData());
      actor->SetBackfaceProperty(back);

      renderer->AddActor(actor);
      renderer->SetBackground(colors->GetColor3d("Burlywood").GetData());
      renderer->ResetCamera();
      renderer->GetActiveCamera()->Azimuth(30);
      renderer->GetActiveCamera()->Elevation(30);
      renderer->GetActiveCamera()->Dolly(1.5);;
      renderer->ResetCameraClippingRange();

      renderWindow->SetSize(640, 480);
      renderWindow->Render();
      interactor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(ShrinkPolyData)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkCommonDataModel
      vtkFiltersGeneral
      vtkFiltersSources
      vtkIOXML
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping ShrinkPolyData: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(ShrinkPolyData MACOSX_BUNDLE ShrinkPolyData.cxx )
      target_link_libraries(ShrinkPolyData PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(ShrinkPolyData MACOSX_BUNDLE ShrinkPolyData.cxx )
      target_link_libraries(ShrinkPolyData PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS ShrinkPolyData
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build ShrinkPolyData

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

    cd ShrinkPolyData/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:

    ./ShrinkPolyData

WINDOWS USERS

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