# RectilinearGridToTetrahedra

VTKExamples/Cxx/RectilinearGrid/RectilinearGridToTetrahedra

### Code

RectilinearGridToTetrahedra.cxx

    #include <vtkVersion.h>
    #include <vtkSmartPointer.h>
    #include <vtkXMLUnstructuredGridWriter.h>
    #include <vtkRectilinearGrid.h>
    #include <vtkRectilinearGridToTetrahedra.h>
    #include <vtkUnstructuredGrid.h>
    #include <vtkMath.h>
    #include <vtkDoubleArray.h>

    int main(int, char *[])
    {
      // Create a grid
      vtkSmartPointer<vtkRectilinearGrid> grid =
        vtkSmartPointer<vtkRectilinearGrid>::New();

      grid->SetDimensions(5,4,3);

      vtkSmartPointer<vtkDoubleArray> xArray =
        vtkSmartPointer<vtkDoubleArray>::New();
      xArray->InsertNextValue(0.0);
      xArray->InsertNextValue(1.0);
      xArray->InsertNextValue(2.0);
      xArray->InsertNextValue(3.0);
      xArray->InsertNextValue(4.0);

      vtkSmartPointer<vtkDoubleArray> yArray =
        vtkSmartPointer<vtkDoubleArray>::New();
      yArray->InsertNextValue(0.0);
      yArray->InsertNextValue(1.0);
      yArray->InsertNextValue(2.0);
      yArray->InsertNextValue(3.0);

      vtkSmartPointer<vtkDoubleArray> zArray =
        vtkSmartPointer<vtkDoubleArray>::New();
      zArray->InsertNextValue(0.0);
      zArray->InsertNextValue(1.0);
      zArray->InsertNextValue(2.0);

      grid->SetXCoordinates(xArray);
      grid->SetYCoordinates(yArray);
      grid->SetZCoordinates(zArray);

      vtkSmartPointer<vtkRectilinearGridToTetrahedra> rectilinearGridToTetrahedra =
        vtkSmartPointer<vtkRectilinearGridToTetrahedra>::New();
    #if VTK_MAJOR_VERSION <= 5
      rectilinearGridToTetrahedra->SetInputConnection(grid->GetProducerPort());
    #else
      rectilinearGridToTetrahedra->SetInputData(grid);
    #endif
      rectilinearGridToTetrahedra->Update();

      vtkSmartPointer<vtkXMLUnstructuredGridWriter> writer =
        vtkSmartPointer<vtkXMLUnstructuredGridWriter>::New();
      writer->SetFileName("output.vtu");
      writer->SetInputConnection(rectilinearGridToTetrahedra->GetOutputPort());
      writer->Write();

      std::cout << "There are "
                << rectilinearGridToTetrahedra->GetOutput()->GetNumberOfCells()
                << " cells." << std::endl;

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(RectilinearGridToTetrahedra)

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

    add_executable(RectilinearGridToTetrahedra MACOSX_BUNDLE RectilinearGridToTetrahedra.cxx )

    target_link_libraries(RectilinearGridToTetrahedra ${VTK_LIBRARIES})

### Download and Build RectilinearGridToTetrahedra

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

    cd RectilinearGridToTetrahedra/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:

    ./RectilinearGridToTetrahedra

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.