# MiscPointData

VTKExamples/Cxx/PolyData/MiscPointData

### Description

This demo attaches a vector (in this case a float vector of length 1) to each point in a polydata.

### Code

MiscPointData.cxx

    #include <vtkCellData.h>
    #include <vtkDoubleArray.h>
    #include <vtkPoints.h>
    #include <vtkPolyData.h>
    #include <vtkPointData.h>
    #include <vtkSmartPointer.h>
    #include <vtkXMLPolyDataReader.h>
    #include <vtkPolyDataNormals.h>
    #include <vtkFloatArray.h>
    #include <vtkMath.h>
    #include <string>

    int main(int argc, char *argv[])
    {
      // Parse command line arguments
      if(argc != 2)
      {
        std::cout << "Required arguments: Filename" << std::endl;
        return EXIT_FAILURE;
      }

      // Get filename from command line
      std::string filename = argv[1]; //first command line argument

      // Read the file
      vtkSmartPointer<vtkXMLPolyDataReader> reader =
        vtkSmartPointer<vtkXMLPolyDataReader>::New();
      std::cout << "Reading " << filename << std::endl;
      reader->SetFileName(filename.c_str());
      reader->Update();

      // Extract the polydata
      vtkSmartPointer<vtkPolyData> polydata = reader->GetOutput();

      // Get the number of points in the polydata
      vtkIdType idNumPointsInFile = polydata->GetNumberOfPoints();

      // Add distances to each point
      vtkSmartPointer<vtkFloatArray> distances =
        vtkSmartPointer<vtkFloatArray>::New();
      distances->SetNumberOfComponents(1);
      distances->SetName("Distances");

      for (vtkIdType i = 0; i < idNumPointsInFile; i++)
      {
        distances->InsertNextValue(vtkMath::Random(0.0,1.0));
      }

      polydata->GetPointData()->AddArray(distances);

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(MiscPointData)

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

    add_executable(MiscPointData MACOSX_BUNDLE MiscPointData.cxx )

    target_link_libraries(MiscPointData ${VTK_LIBRARIES})

### Download and Build MiscPointData

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

    cd MiscPointData/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:

    ./MiscPointData

WINDOWS USERS

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