# MiscCellData

VTKExamples/Cxx/PolyData/MiscCellData

### Description

This demo attaches a double to a cell (triangle) in a polydata.

### Code

MiscCellData.cxx

    #include <vtkVersion.h>
    #include <vtkCellData.h>
    #include <vtkSmartPointer.h>
    #include <vtkCellArray.h>
    #include <vtkDoubleArray.h>
    #include <vtkTriangle.h>
    #include <vtkPoints.h>
    #include <vtkPolyData.h>
    #include <vtkXMLPolyDataWriter.h>

    int main(int, char *[])
    {
      // We will write the resulting file to Test.vtp so it can be inspected in Paraview
      std::string outputFilename = "output.vtp";

      // Setup 3 points
      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      points->InsertNextPoint(1.0, 0.0, 0.0);
      points->InsertNextPoint(0.0, 0.0, 0.0);
      points->InsertNextPoint(0.0, 1.0, 0.0);

      // Create a triangle
      vtkSmartPointer<vtkTriangle> triangle =
        vtkSmartPointer<vtkTriangle>::New();
      triangle->GetPointIds()->SetId(0,0);
      triangle->GetPointIds()->SetId(1,1);
      triangle->GetPointIds()->SetId(2,2);

      // Add the triangle to a cell array
      vtkSmartPointer<vtkCellArray> triangles =
        vtkSmartPointer<vtkCellArray>::New();
      triangles->InsertNextCell(triangle);

      // Setup data for the triangle. Attach a value of 1.45.
      // This can be anything you wish to store with it)
      vtkSmartPointer<vtkDoubleArray> triangleData =
        vtkSmartPointer<vtkDoubleArray>::New();
      triangleData->SetNumberOfComponents(1); //we will have only 1 value associated with the triangle
      triangleData->SetName("TriangleData"); //set the name of the value
      triangleData->InsertNextValue(1.45); //set the actual value

      // Create a polydata that contains the points,
      // the triangle on those points, and the data
      // array (value) we created for the triangle
      vtkSmartPointer<vtkPolyData> polydata =
        vtkSmartPointer<vtkPolyData>::New();
      polydata->SetPoints(points);
      polydata->SetPolys(triangles);
      polydata->GetCellData()->AddArray(triangleData);

      // Write the file
      vtkSmartPointer<vtkXMLPolyDataWriter> writer =
        vtkSmartPointer<vtkXMLPolyDataWriter>::New();
    #if VTK_MAJOR_VERSION <= 5
      writer->SetInput(polydata);
    #else
      writer->SetInputData(polydata);
    #endif
      writer->SetFileName(outputFilename.c_str());
      writer->Write();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(MiscCellData)

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

    add_executable(MiscCellData MACOSX_BUNDLE MiscCellData.cxx )

    target_link_libraries(MiscCellData ${VTK_LIBRARIES})

### Download and Build MiscCellData

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

    cd MiscCellData/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:

    ./MiscCellData

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.