# SaveSceneToFile

VTKExamples/Cxx/Utilities/SaveSceneToFile

### Description

This example saves a vtkCamera's parameters in a file.

To see how the scene is saved and restored,

1. Interact with the scene. Press the e key to exit the first iteractor. The current state of the scene's vtkCamera will be saved in the file.

2. Interact with the scene again. Press the e key to exit the second interactor. The saved file is read and the scene will be restored to the previous state.

3. Press the e key to exit the example.

Info

This example uses snippets.

Other Languages

See (Python)

### Code

SaveSceneToFile.cxx

    #include <vtkSmartPointer.h>

    #include <vtkBYUReader.h>
    #include <vtkOBJReader.h>
    #include <vtkPLYReader.h>
    #include <vtkPolyDataReader.h>
    #include <vtkSTLReader.h>
    #include <vtkXMLPolyDataReader.h>
    #include <vtkSphereSource.h>

    #include <vtkActor.h>
    #include <vtkPolyDataMapper.h>
    #include <vtkProperty.h>
    #include <vtkRenderWindow.h>
    #include <vtkRenderWindowInteractor.h>
    #include <vtkRenderer.h>
    #include <vtkCamera.h>

    #include <vtkNamedColors.h>
    #include <vtkTimerLog.h>
    #include <vtksys/SystemTools.hxx>
    #include <vtksys/RegularExpression.hxx>

    namespace
    {
    vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName);
    }
    #include <vtkActor.h>
    #include <vtkCamera.h>
    namespace
    {
    void SaveSceneToFile(std::string fileName,
                         vtkActor *actor,
                         vtkCamera *camera);
    }
    #include <vtkActor.h>
    #include <vtkCamera.h>
    namespace
    {
    void RestoreSceneFromFile(std::string fileName,
                              vtkActor *actor,
                              vtkCamera *camera);
    }
    int main (int argc, char *argv[])
    {
      vtkSmartPointer<vtkPolyData> polyData = ReadPolyData(argc > 1 ? argv[1] : "");;

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

      vtkSmartPointer<vtkPolyDataMapper> mapper =
        vtkSmartPointer<vtkPolyDataMapper>::New();
      mapper->SetInputData(polyData);

      vtkSmartPointer<vtkActor> actor =
        vtkSmartPointer<vtkActor>::New();
      actor->SetMapper(mapper);
      actor->GetProperty()->SetDiffuseColor(colors->GetColor3d("Crimson").GetData());
      actor->GetProperty()->SetSpecular(.6);
      actor->GetProperty()->SetSpecularPower(30);
    ;
      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("Silver").GetData());

      // Interact to change camera
      renderWindow->Render();
      renderWindowInteractor->Start();

      // After the interaction is done, save the scene
      SaveSceneToFile(argv[2], actor, renderer->GetActiveCamera());
      renderWindow->Render();
      renderWindowInteractor->Start();

      // After interaction , restore the scene
      RestoreSceneFromFile(argv[2], actor, renderer->GetActiveCamera());
      renderWindow->Render();
      renderWindowInteractor->Start();

    return EXIT_SUCCESS;
    }

    namespace
    {
    #include <fstream>
    void SaveSceneToFile(std::string fileName,
                         vtkActor * /* actor */,
                         vtkCamera *camera)
    {
    // Actor
    //  Position, orientation, origin, scale, usrmatrix, usertransform
    //Camera
    //  FocalPoint, Position, ViewUp, ViewAngle, ClippingRange
      std::ofstream saveFile(fileName, std::ofstream::out);
      double vector[3];
      double scalar;

      camera->GetFocalPoint(vector);
      saveFile << "Camera:FocalPoint "
               << vector[0] << ", "
               << vector[1] << ", "
               << vector[2] << std::endl;
      camera->GetPosition(vector);
      saveFile << "Camera:Position "
               << vector[0] << ", "
               << vector[1] << ", "
               << vector[2] << std::endl;
      camera->GetViewUp(vector);
      saveFile << "Camera:ViewUp "
               << vector[0] << ", "
               << vector[1] << ", "
               << vector[2] << std::endl;
      scalar = camera->GetViewAngle();
      saveFile << "Camera:ViewAngle "
               << scalar << std::endl;
      camera->GetClippingRange(vector);
      saveFile << "Camera:ClippingRange "
               << vector[0] << ", "
               << vector[1] << std::endl;
      saveFile.close();
    }
    }
    namespace
    {
    #include <fstream>
    void RestoreSceneFromFile(std::string fileName,
                              vtkActor * /* actor */,
                              vtkCamera *camera)
    {
      std::ifstream saveFile(fileName);
      std::string line;

      vtksys::RegularExpression reCP("^Camera:Position");
      vtksys::RegularExpression reCFP("^Camera:FocalPoint");
      vtksys::RegularExpression reCVU("^Camera:ViewUp");
      vtksys::RegularExpression reCVA("^Camera:ViewAngle");
      vtksys::RegularExpression reCCR("^Camera:ClippingRange");
      vtksys::RegularExpression floatNumber(
          "[^0-9\\.\\-]*([0-9e\\.\\-]*[^,])[^0-9\\.\\-]*([0-9e\\.\\-]*[^,])[^0-9\\.\\-]*([0-9e\\.\\-]*[^,])");
      vtksys::RegularExpression floatScalar("[^0-9\\.\\-]*([0-9\\.\\-e]*[^,])");

      while (std::getline(saveFile, line) && ! saveFile.eof())
      {
        if (reCFP.find(line))
        {
          std::string rest(line, reCFP.end());
          if (floatNumber.find(rest))
          {
            camera->SetFocalPoint(
              atof(floatNumber.match(1).c_str()),
              atof(floatNumber.match(2).c_str()),
              atof(floatNumber.match(3).c_str()));
          }
        }
        else if (reCP.find(line))
        {
          std::string rest(line, reCP.end());
          if (floatNumber.find(rest))
          {
            camera->SetPosition(
              atof(floatNumber.match(1).c_str()),
              atof(floatNumber.match(2).c_str()),
              atof(floatNumber.match(3).c_str()));
          }
        }
        else if (reCVU.find(line))
        {
          std::string rest(line, reCVU.end());
          if (floatNumber.find(rest))
          {
            camera->SetViewUp(
              atof(floatNumber.match(1).c_str()),
              atof(floatNumber.match(2).c_str()),
              atof(floatNumber.match(3).c_str()));
          }
        }
        else if (reCVA.find(line))
        {
          std::string rest(line, reCVA.end());
          if (floatScalar.find(rest))
          {
            camera->SetViewAngle(
              atof(floatScalar.match(1).c_str()));
          }
        }
        else if (reCCR.find(line))
        {
          std::string rest(line, reCCR.end());
          if (floatNumber.find(rest))
          {
            camera->SetClippingRange(
              atof(floatNumber.match(1).c_str()),
              atof(floatNumber.match(2).c_str()));
          }
        }
        else
        {
          std::cout << "Unrecognized line: " << line << std::endl;
        }
      }
      saveFile.close();
    }
    }
    namespace
    {
    vtkSmartPointer<vtkPolyData> ReadPolyData(const char *fileName)
    {
      vtkSmartPointer<vtkPolyData> polyData;
      std::string extension = vtksys::SystemTools::GetFilenameExtension(std::string(fileName));
      if (extension == ".ply")
      {
        vtkSmartPointer<vtkPLYReader> reader =
          vtkSmartPointer<vtkPLYReader>::New();
        reader->SetFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else if (extension == ".vtp")
      {
        vtkSmartPointer<vtkXMLPolyDataReader> reader =
          vtkSmartPointer<vtkXMLPolyDataReader>::New();
        reader->SetFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else if (extension == ".obj")
      {
        vtkSmartPointer<vtkOBJReader> reader =
          vtkSmartPointer<vtkOBJReader>::New();
        reader->SetFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else if (extension == ".stl")
      {
        vtkSmartPointer<vtkSTLReader> reader =
          vtkSmartPointer<vtkSTLReader>::New();
        reader->SetFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else if (extension == ".vtk")
      {
        vtkSmartPointer<vtkPolyDataReader> reader =
          vtkSmartPointer<vtkPolyDataReader>::New();
        reader->SetFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else if (extension == ".g")
      {
        vtkSmartPointer<vtkBYUReader> reader =
          vtkSmartPointer<vtkBYUReader>::New();
        reader->SetGeometryFileName (fileName);
        reader->Update();
        polyData = reader->GetOutput();
      }
      else
      {
        vtkSmartPointer<vtkSphereSource> source =
          vtkSmartPointer<vtkSphereSource>::New();
        source->Update();
        polyData = source->GetOutput();
      }
      return polyData;
    }
    }

### CMakeLists.txt

    cmake_minimum_required(VERSION 3.3 FATAL_ERROR)

    project(SaveSceneToFile)

    find_package(VTK COMPONENTS
      vtkCommonColor
      vtkCommonCore
      vtkCommonSystem
      vtkFiltersSources
      vtkIOGeometry
      vtkIOLegacy
      vtkIOPLY
      vtkIOXML
      vtkInteractionStyle
      vtkRenderingCore
      vtkRenderingFreeType
      vtkRenderingOpenGL2 QUIET)
    if (NOT VTK_FOUND)
      message("Skipping SaveSceneToFile: ${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(SaveSceneToFile MACOSX_BUNDLE SaveSceneToFile.cxx )
      target_link_libraries(SaveSceneToFile PRIVATE ${VTK_LIBRARIES})
    else ()
      # include all components
      add_executable(SaveSceneToFile MACOSX_BUNDLE SaveSceneToFile.cxx )
      target_link_libraries(SaveSceneToFile PRIVATE ${VTK_LIBRARIES})
      # vtk_module_autoinit is needed
      vtk_module_autoinit(
        TARGETS SaveSceneToFile
        MODULES ${VTK_LIBRARIES}
        )
    endif ()

### Download and Build SaveSceneToFile

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

    cd SaveSceneToFile/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:

    ./SaveSceneToFile

WINDOWS USERS

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