# SelectPolyData

VTKExamples/Cxx/PolyData/SelectPolyData

### Code

SelectPolyData.cxx

    #include <vtkSmartPointer.h>
    #include <vtkProperty.h>
    #include <vtkSelectPolyData.h>
    #include <vtkSphereSource.h>
    #include <vtkClipPolyData.h>
    #include <vtkProperty.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkLODActor.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>

    #include <vtkNamedColors.h>

    int main(int, char *[])
    {

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

      vtkSmartPointer<vtkSphereSource> sphereSource =
        vtkSmartPointer<vtkSphereSource>::New();
      sphereSource->SetPhiResolution(50);
      sphereSource->SetThetaResolution(100);
      sphereSource->Update();

      vtkSmartPointer<vtkPoints> selectionPoints =
        vtkSmartPointer<vtkPoints>::New();

      selectionPoints->InsertPoint( 0, -0.16553, 0.135971, 0.451972 );
      selectionPoints->InsertPoint( 1, -0.0880123, -0.134952, 0.4747);
      selectionPoints->InsertPoint( 2,  0.00292618, -0.134604, 0.482459 );
      selectionPoints->InsertPoint( 3, 0.0641941, 0.067112, 0.490947);
      selectionPoints->InsertPoint( 4, 0.15577, 0.0734765, 0.469245);
      selectionPoints->InsertPoint( 5, 0.166667, -0.129217, 0.454622 );
      selectionPoints->InsertPoint( 6, 0.241259, -0.123363, 0.420581);
      selectionPoints->InsertPoint( 7,  0.240334, 0.0727106, 0.432555);
      selectionPoints->InsertPoint( 8, 0.308529, 0.0844311, 0.384357 );
      selectionPoints->InsertPoint( 9, 0.32672, -0.121674, 0.359187);
      selectionPoints-> InsertPoint( 10, 0.380721, -0.117342, 0.302527);
      selectionPoints ->InsertPoint( 11, 0.387804, 0.0455074, 0.312375 );
      selectionPoints ->InsertPoint( 12, 0.43943, -0.111673, 0.211707);
      selectionPoints ->InsertPoint( 13, 0.470984, -0.0801913, 0.147919);
      selectionPoints ->InsertPoint( 14, 0.436777, 0.0688872, 0.233021 );
      selectionPoints ->InsertPoint( 15, 0.44874, 0.188852, 0.109882);
      selectionPoints ->InsertPoint( 16, 0.391352, 0.254285, 0.176943);
      selectionPoints ->InsertPoint( 17, 0.373274, 0.154162, 0.294296 );
      selectionPoints ->InsertPoint( 18, 0.274659, 0.311654, 0.276609);
      selectionPoints ->InsertPoint( 19, 0.206068, 0.31396, 0.329702);
      selectionPoints ->InsertPoint( 20, 0.263789, 0.174982, 0.387308 );
      selectionPoints ->InsertPoint( 21, 0.213034, 0.175485, 0.417142);
      selectionPoints ->InsertPoint( 22, 0.169113, 0.261974, 0.390286);
      selectionPoints ->InsertPoint( 23, 0.102552, 0.25997, 0.414814 );
      selectionPoints ->InsertPoint( 24, 0.131512, 0.161254, 0.454705);
      selectionPoints ->InsertPoint( 25, 0.000192443, 0.156264, 0.475307);
      selectionPoints ->InsertPoint( 26, -0.0392091, 0.000251724, 0.499943);
      selectionPoints ->InsertPoint( 27, -0.096161, 0.159646, 0.46438 );

      vtkSmartPointer<vtkSelectPolyData> loop =
        vtkSmartPointer<vtkSelectPolyData>::New();
      loop->SetInputConnection(sphereSource->GetOutputPort());
      loop->SetLoop(selectionPoints);
      loop->GenerateSelectionScalarsOn();
      loop->SetSelectionModeToSmallestRegion(); //negative scalars inside

      vtkSmartPointer<vtkClipPolyData> clip = //clips out positive region
        vtkSmartPointer<vtkClipPolyData>::New();
      clip->SetInputConnection(loop->GetOutputPort());

      vtkSmartPointer<vtkPolyDataMapper> clipMapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      clipMapper->SetInputConnection(clip->GetOutputPort());
      clipMapper->ScalarVisibilityOff();

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

      vtkSmartPointer<vtkLODActor> clipActor =
        vtkSmartPointer<vtkLODActor>::New();
      clipActor->SetMapper(clipMapper);
      clipActor->SetBackfaceProperty(backProp);
      clipActor->GetProperty()->SetColor(colors->GetColor3d("banana").GetData());

      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 (clipActor);
      renderer->SetBackground (colors->GetColor3d("slate_grey").GetData());

      renderWindow->SetSize (500, 500);

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(SelectPolyData)

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

    add_executable(SelectPolyData MACOSX_BUNDLE SelectPolyData.cxx )

    target_link_libraries(SelectPolyData ${VTK_LIBRARIES})

### Download and Build SelectPolyData

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

    cd SelectPolyData/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:

    ./SelectPolyData

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.