# CleanPolyData

VTKExamples/Cxx/PolyData/CleanPolyData

### Description

When a cube is created, it has 24 vertices (4 for each face). This is done because the normal at each face is very different. Often we would want a cube to only have 8 vertices. The vtkCleanPolyData filter removes coincident points, resulting in the cube we would expect.

### Code

CleanPolyData.cxx

    #include <vtkSmartPointer.h>
    #include <vtkCubeSource.h>
    #include <vtkPolyData.h>
    #include <vtkCleanPolyData.h>

    int main(int, char *[])
    {
      vtkSmartPointer<vtkCubeSource> cubeSource =
        vtkSmartPointer<vtkCubeSource>::New();
      cubeSource->Update();

      std::cout << "Input cube has " << cubeSource->GetOutput()->GetNumberOfPoints()
        << " vertices." << std::endl;

      vtkSmartPointer<vtkCleanPolyData> cleanPolyData =
          vtkSmartPointer<vtkCleanPolyData>::New();
      cleanPolyData->SetInputConnection(cubeSource->GetOutputPort());
      cleanPolyData->Update();

      std::cout << "Cleaned cube has " << cleanPolyData->GetOutput()->GetNumberOfPoints()
        << " vertices." << std::endl;

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(CleanPolyData)

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

    add_executable(CleanPolyData MACOSX_BUNDLE CleanPolyData.cxx )

    target_link_libraries(CleanPolyData ${VTK_LIBRARIES})

### Download and Build CleanPolyData

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

    cd CleanPolyData/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:

    ./CleanPolyData

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.