# ReadOBJ

VTKExamples/Cxx/IO/ReadOBJ

### Description

This example demonstrates how to read a [.obj file|Wavefront OBJ]]([wikipedia:Wavefront) file. The result is displayed.

### Code

ReadOBJ.cxx

    #include <vtkOBJReader.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkActor.h>
    #include <vtkRenderer.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkSmartPointer.h>
    #include <string>

    int main(int argc, char* argv[])
    {
      // Parse command line arguments
      if(argc != 2)
      {
        std::cout << "Usage: " << argv[0] << " Filename(.obj)" << std::endl;
        return EXIT_FAILURE;
      }

      std::string filename = argv[1];
      vtkSmartPointer<vtkOBJReader> reader =
        vtkSmartPointer<vtkOBJReader>::New();
      reader->SetFileName(filename.c_str());
      reader->Update();

      // Visualize
      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();
      renderer->AddActor(actor);
      renderer->SetBackground(.3, .6, .3); // Background color green

      vtkSmartPointer<vtkRenderWindow> renderWindow =
        vtkSmartPointer<vtkRenderWindow>::New();
      renderWindow->AddRenderer(renderer);

      vtkSmartPointer<vtkRenderWindowInteractor> renderWindowInteractor =
        vtkSmartPointer<vtkRenderWindowInteractor>::New();
      renderWindowInteractor->SetRenderWindow(renderWindow);

      renderWindowInteractor->Start();

      return EXIT_SUCCESS;
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 2.8)

    PROJECT(ReadOBJ)

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

    add_executable(ReadOBJ MACOSX_BUNDLE ReadOBJ.cxx )

    target_link_libraries(ReadOBJ ${VTK_LIBRARIES})

### Download and Build ReadOBJ

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

    cd ReadOBJ/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:

    ./ReadOBJ

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.