# DelimitedTextReader

VTKExamples/Cxx/InfoVis/DelimitedTextReader

### Description

This example takes a plain text file of coordinates and normals (x y z nx ny nz) and reads them into a vtkPolyData and displays them on the screen. This can be easily changed to reading a file with any delimiter by changing the argument of Reader->SetFieldDelimiterCharacters(" ");

Here is an example file:

0.0 0.0 0.0 1.0 2.0 3.0 1.0 0.0 0.0 4.0 5.0 6.1 0.0 1.0 0.0 7.2 8.3 9.4

### Code

DelimitedTextReader.cxx

    #include <vtkSmartPointer.h>
    #include <vtkDelimitedTextReader.h>

    #include <vtkProperty.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkDoubleArray.h>
    #include <vtkTable.h>
    #include <vtkPointData.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkVersionMacros.h> // For version macros
    #include <vtkVertexGlyphFilter.h>

    #include <vtkNamedColors.h>
    int main(int argc, char* argv[])
    {
      // Verify input arguments
      if(argc != 2)
      {
        std::cout << "Usage: " << argv[0]
                  << " Filename(.xyz)" << std::endl;
        return EXIT_FAILURE;
      }

      std::string inputFilename = argv[1];

      vtkSmartPointer<vtkDelimitedTextReader> reader =
        vtkSmartPointer<vtkDelimitedTextReader>::New();
      reader->SetFileName(inputFilename.c_str());
      reader->DetectNumericColumnsOn();
      reader->SetFieldDelimiterCharacters(" ");
      reader->Update();

      vtkTable* table = reader->GetOutput();

      vtkSmartPointer<vtkPoints> points =
        vtkSmartPointer<vtkPoints>::New();
      vtkSmartPointer<vtkDoubleArray> normals =
        vtkSmartPointer<vtkDoubleArray>::New();

      normals->SetNumberOfComponents(3); //3d normals (ie x,y,z)

      std::cout << "Table has " << table->GetNumberOfRows()
                << " rows." << std::endl;
      std::cout << "Table has " << table->GetNumberOfColumns()
                << " columns." << std::endl;

      for(vtkIdType i = 0; i < table->GetNumberOfRows(); i++)
      {
        std::cout << "x: " << (table->GetValue(i,0)).ToDouble()
                  << " y: " << (table->GetValue(i,1)).ToDouble()
                  << " z: " << (table->GetValue(i,2)).ToDouble();

        points->InsertNextPoint((table->GetValue(i,0)).ToDouble(),
                                (table->GetValue(i,1)).ToDouble(),
                                (table->GetValue(i,2)).ToDouble());

        double n[3];
        n[0] = (table->GetValue(i,3)).ToDouble();
        n[1] = (table->GetValue(i,4)).ToDouble();
        n[2] = (table->GetValue(i,5)).ToDouble();

        std::cout << " n: " << n[0] << " " << n[1] << " " << n[2] << std::endl;
        normals->InsertNextTuple(n);
      }

      std::cout << "There are " << points->GetNumberOfPoints()
                << " points." << std::endl;

      vtkSmartPointer<vtkPolyData> polydata =
        vtkSmartPointer<vtkPolyData>::New();
      polydata->SetPoints(points);
      polydata->GetPointData()->SetNormals(normals);

      vtkSmartPointer<vtkVertexGlyphFilter> glyphFilter =
        vtkSmartPointer<vtkVertexGlyphFilter>::New();
      glyphFilter->SetInputData(polydata);
      glyphFilter->Update();

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

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputConnection(glyphFilter->GetOutputPort());

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->SetPointSize(30);
      actor->GetProperty()->SetColor(colors->GetColor3d("Tomato").GetData());

      vtkSmartPointer<vtkRenderer> renderer =
        vtkSmartPointer<vtkRenderer>::New();
      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);
      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderer->AddActor(actor);
      renderer->SetBackground(colors->GetColor3d("Mint").GetData());

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(DelimitedTextReader)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkCommonDataModel
      vtkFiltersGeneral
      vtkIOInfovis
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping DelimitedTextReader: ${VTK_NOT_FOUND_MESSAGE}")
      return ()
    endif()
    message (STATUS "VTK_VERSION: ${VTK_VERSION}")
    if (VTK_VERSION VERSION_LESS "8.90.0")
      # old system
      include(${VTK_USE_FILE})
      add_executable(DelimitedTextReader MACOSX_BUNDLE DelimitedTextReader.cxx )
      target_link_libraries(DelimitedTextReader PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(DelimitedTextReader MACOSX_BUNDLE DelimitedTextReader.cxx )
      target_link_libraries(DelimitedTextReader PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS DelimitedTextReader
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build DelimitedTextReader

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

    cd DelimitedTextReader/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:

    ./DelimitedTextReader

WINDOWS USERS

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