# WritePLY

VTKExamples/Cxx/IO/WritePLY

### Description

Note

Unlike vtkPolyDataXMLWriter and most other VTK writers, to write colors to the .ply file you must specify to the vtkPLYWriter:

plyWriter->SetArrayName("Colors");

where your color array was created/named like this:

vtkSmartPointer vtkUnsignedCharArray> colors = vtkSmartPointer vtkUnsignedCharArray>::New(); colors->SetNumberOfComponents(3); colors->SetName("Colors");

(This was found in response to a user question on StackOverflow: http://stackoverflow.com/questions/17783612/save-mesh-with-rgb-in vtk/19525938)

### Code

WritePLY.cxx

    #include <vtkPolyData.h>
    #include <vtkPLYWriter.h>
    #include <vtkPLYReader.h>
    #include <vtkSmartPointer.h>
    #include <vtkSphereSource.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindowInteractor.h>

    int main(int argc, char *argv[])
    {
      if(argc != 2)
      {
        std::cout << "Required parameters: filename.ply" << std::endl;
        return EXIT_FAILURE;
      }

      std::string filename = argv[1];

      vtkSmartPointer<vtkSphereSource> sphereSource =
        vtkSmartPointer<vtkSphereSource>::New();
      sphereSource->Update();

      vtkSmartPointer<vtkPLYWriter> plyWriter =
        vtkSmartPointer<vtkPLYWriter>::New();
      plyWriter->SetFileName(filename.c_str());
      plyWriter->SetInputConnection(sphereSource->GetOutputPort());
      plyWriter->Write();

      // Read and display for verification
      vtkSmartPointer<vtkPLYReader> reader =
        vtkSmartPointer<vtkPLYReader>::New();
      reader->SetFileName(filename.c_str());
      reader->Update();

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

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);

      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(.3, .6, .3); // Background color green

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

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(WritePLY)

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

    add_executable(WritePLY MACOSX_BUNDLE WritePLY.cxx )

    target_link_libraries(WritePLY ${VTK_LIBRARIES})

### Download and Build WritePLY

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

    cd WritePLY/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:

    ./WritePLY

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.