OpenCV/opencv_contrib/modules/sfm/samples/import_reconstruction.cpp

#include <opencv2/sfm.hpp>
#include <opencv2/viz.hpp>

#include <iostream>

using namespace std;
using namespace cv;
using namespace cv::sfm;

static void help() {
  cout
      << "\n---------------------------------------------------------------------------\n"
      << " This program shows how to import a reconstructed scene in the \n"
      << " OpenCV Structure From Motion (SFM) module.\n"
      << " Usage:\n"
      << "        example_sfm_import_reconstruction <path_to_file>\n"
      << " where: file_path is the absolute path file into your system which contains\n"
      << "        the reconstructed scene. \n"
      << "---------------------------------------------------------------------------\n\n"
      << endl;
}


int main(int argc, char* argv[])
{
  /// Read input parameters

  if ( argc != 2 ) {
    help();
    exit(0);
  }

  /// Immport a reconstructed scene

  vector<Mat> Rs, Ts, Ks, points3d;
  importReconstruction(argv[1], Rs, Ts, Ks, points3d, SFM_IO_BUNDLER);


  /// Create 3D windows

  viz::Viz3d window("Coordinate Frame");
             window.setWindowSize(Size(500,500));
             window.setWindowPosition(Point(150,150));
             window.setBackgroundColor(); // black by default


  /// Create the pointcloud

  vector<Vec3d> point_cloud;
  for (int i = 0; i < points3d.size(); ++i){
    point_cloud.push_back(Vec3f(points3d[i]));
  }


  /// Recovering cameras

  vector<Affine3d> path;
  for (size_t i = 0; i < Rs.size(); ++i)
    path.push_back(Affine3d(Rs[i], Ts[i]));


  /// Create and show widgets

  viz::WCloud cloud_widget(point_cloud, viz::Color::green());
  viz::WTrajectory trajectory(path, viz::WTrajectory::FRAMES, 0.5);
  viz::WTrajectoryFrustums frustums(path, Vec2f(0.889484, 0.523599), 0.5,
                                    viz::Color::yellow());

  window.showWidget("point_cloud", cloud_widget);
  window.showWidget("cameras", trajectory);
  window.showWidget("frustums", frustums);


  /// Wait for key 'q' to close the window
  cout << endl << "Press 'q' to close each windows ... " << endl;

  window.spin();

  return 0;
}