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SaveSceneToFile

vtk-examples/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)

Question

If you have a question about this example, please use the VTK Discourse Forum

Code

SaveSceneToFile.cxx

#include <vtkActor.h>
#include <vtkBYUReader.h>
#include <vtkCamera.h>
#include <vtkNamedColors.h>
#include <vtkNew.h>
#include <vtkOBJReader.h>
#include <vtkPLYReader.h>
#include <vtkPolyDataMapper.h>
#include <vtkPolyDataReader.h>
#include <vtkProperty.h>
#include <vtkRenderWindow.h>
#include <vtkRenderWindowInteractor.h>
#include <vtkRenderer.h>
#include <vtkSTLReader.h>
#include <vtkSmartPointer.h>
#include <vtkSphereSource.h>
#include <vtkTimerLog.h>
#include <vtkXMLPolyDataReader.h>

#include <vtksys/RegularExpression.hxx>
#include <vtksys/SystemTools.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[])
{
  auto polyData = ReadPolyData(argc > 1 ? argv[1] : "");

  // Visualize
  vtkNew<vtkNamedColors> colors;

  vtkNew<vtkPolyDataMapper> mapper;
  mapper->SetInputData(polyData);

  vtkNew<vtkActor> actor;
  actor->SetMapper(mapper);
  actor->GetProperty()->SetDiffuseColor(
      colors->GetColor3d("Crimson").GetData());
  actor->GetProperty()->SetSpecular(.6);
  actor->GetProperty()->SetSpecularPower(30);
  ;
  vtkNew<vtkRenderer> renderer;
  vtkNew<vtkRenderWindow> renderWindow;
  renderWindow->AddRenderer(renderer);
  vtkNew<vtkRenderWindowInteractor> renderWindowInteractor;
  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
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
namespace {
vtkSmartPointer<vtkPolyData> ReadPolyData(const char* fileName)
{
  vtkSmartPointer<vtkPolyData> polyData;
  std::string extension =
      vtksys::SystemTools::GetFilenameExtension(std::string(fileName));
  if (extension == ".ply")
  {
    vtkNew<vtkPLYReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtp")
  {
    vtkNew<vtkXMLPolyDataReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".obj")
  {
    vtkNew<vtkOBJReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".stl")
  {
    vtkNew<vtkSTLReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".vtk")
  {
    vtkNew<vtkPolyDataReader> reader;
    reader->SetFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else if (extension == ".g")
  {
    vtkNew<vtkBYUReader> reader;
    reader->SetGeometryFileName(fileName);
    reader->Update();
    polyData = reader->GetOutput();
  }
  else
  {
    vtkNew<vtkSphereSource> source;
    source->Update();
    polyData = source->GetOutput();
  }
  return polyData;
}
} // namespace

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
  vtkRenderingContextOpenGL2
  vtkRenderingCore
  vtkRenderingFreeType
  vtkRenderingGL2PSOpenGL2
  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.