tutorial-ibvs-4pts-ogre-tracking.cpp

#include <visp/vpDisplayX.h>
#include <visp/vpDisplayGDI.h>
#include <visp/vpAROgre.h>
#include <visp/vpFeatureBuilder.h>
#include <visp/vpPose.h>
#include <visp/vpServo.h>
#include <visp/vpServoDisplay.h>
#include <visp/vpSimulatorCamera.h>

void display_trajectory(const vpImage<unsigned char> &I, const std::vector<vpDot2> &dot, unsigned int thickness)
{
  static std::vector<vpImagePoint> traj[4];
  for (unsigned int i=0; i<4; i++) {
    traj[i].push_back(dot[i].getCog());
  }
  for (unsigned int i=0; i<4; i++) {
    for (unsigned int j=1; j<traj[i].size(); j++) {
      vpDisplay::displayLine(I, traj[i][j-1], traj[i][j], vpColor::green, thickness);
    }
  }
}

#if defined(VISP_HAVE_OGRE)
void ogre_get_render_image(vpAROgre &ogre, const vpImage<unsigned char> &background,
                         #if VISP_VERSION_INT > VP_VERSION_INT(2,7,0)
                           const
                         #endif
                           vpHomogeneousMatrix &cMo, vpImage<unsigned char> &I)
{
  static vpImage<vpRGBa> Irender; // Image from ogre scene rendering
  ogre.display(background, cMo);
  ogre.getRenderingOutput(Irender, cMo);

  vpImageConvert::convert(Irender, I);
  // Due to the light that was added to the scene, we need to threshold the image
  vpImageTools::binarise(I, (unsigned char)254, (unsigned char)255, (unsigned char)0, (unsigned char)255, (unsigned char)255);
}
#endif

int main()
{
#if defined(VISP_HAVE_OGRE) && (defined(VISP_HAVE_X11) || defined(VISP_HAVE_GDI))
  unsigned int thickness = 3;

  vpHomogeneousMatrix cdMo(0, 0, 0.75, 0, 0, 0);
  vpHomogeneousMatrix cMo(0.15, -0.1, 1., vpMath::rad(10), vpMath::rad(-10), vpMath::rad(50));

  // Color image used as background texture.
  vpImage<unsigned char> background(480, 640, 255);

  // Parameters of our camera
  vpCameraParameters cam(840, 840, background.getWidth()/2, background.getHeight()/2);

  // Define the target as 4 points
  std::vector<vpPoint> point(4) ;
  point[0].setWorldCoordinates(-0.1,-0.1, 0);
  point[1].setWorldCoordinates( 0.1,-0.1, 0);
  point[2].setWorldCoordinates( 0.1, 0.1, 0);
  point[3].setWorldCoordinates(-0.1, 0.1, 0);

  // Our object
  // A simulator with the camera parameters defined above,
  // and the background image size
  vpAROgre ogre;
  ogre.setCameraParameters(cam);
  ogre.setShowConfigDialog(false);
  ogre.addResource("./"); // Add the path to the Sphere.mesh resource
  ogre.init(background, false, true);
  //ogre.setWindowPosition(680, 400);

  // Create the scene that contains 4 spheres
  // Sphere.mesh contains a sphere with 1 meter radius
  std::vector<std::string> name(4);
  for (int i=0; i<4; i++) {
    std::ostringstream s; s << "Sphere" <<  i; name[i] = s.str();
    ogre.load(name[i], "Sphere.mesh");
    ogre.setScale(name[i], 0.02f, 0.02f, 0.02f); // Rescale the sphere to 2 cm radius
    // Set the position of each sphere in the object frame
    ogre.setPosition(name[i], vpTranslationVector(point[i].get_oX(), point[i].get_oY(), point[i].get_oZ()));
    ogre.setRotation(name[i], vpRotationMatrix(M_PI/2, 0, 0));
  }

  // Add an optional point light source
  Ogre::Light * light = ogre.getSceneManager()->createLight();
  light->setDiffuseColour(1, 1, 1); // scaled RGB values
  light->setSpecularColour(1, 1, 1); // scaled RGB values
  light->setPosition((Ogre::Real)cdMo[0][3], (Ogre::Real)cdMo[1][3], (Ogre::Real)(-cdMo[2][3]));
  light->setType(Ogre::Light::LT_POINT);

  vpServo task ;
  task.setServo(vpServo::EYEINHAND_CAMERA);
  task.setInteractionMatrixType(vpServo::CURRENT);
  task.setLambda(0.5);

  // Image used for the image processing
  vpImage<unsigned char> I;

  // Render the scene at the desired position
  ogre_get_render_image(ogre, background, cdMo, I);

  // Display the image in which we will do the tracking
#if defined(VISP_HAVE_X11)
  vpDisplayX d(I, 0, 0, "Camera view at desired position");
#elif defined(VISP_HAVE_GDI)
  vpDisplayGDI d(I, 0, 0, "Camera view at desired position");
#else
  std::cout << "No image viewer is available..." << std::endl;
#endif

  vpDisplay::display(I);
  vpDisplay::displayCharString(I, 10, 10, "Click in the 4 dots to learn their positions", vpColor::red);
  vpDisplay::flush(I);

  std::vector<vpDot2> dot(4);
  vpFeaturePoint p[4], pd[4];

  for (int i = 0 ; i < 4 ; i++) {
    // Compute the desired feature at the desired position
    dot[i].setGraphics(true);
    dot[i].setGraphicsThickness(thickness);
    dot[i].initTracking(I);
    vpDisplay::flush(I);
    vpFeatureBuilder::create(pd[i], cam, dot[i].getCog());
  }

  // Render the scene at the initial position
  ogre_get_render_image(ogre, background, cMo, I);

  vpDisplay::display(I);
  vpDisplay::setTitle(I, "Current camera view");
  vpDisplay::displayCharString(I, 10, 10, "Click in the 4 dots to initialise the tracking and start the servo", vpColor::red);
  vpDisplay::flush(I);

  for (int i = 0 ; i < 4 ; i++) {
    // We notice that if we project the scene at a given pose, the pose estimated from
    // the rendered image differs a little. That's why we cannot simply compute the desired
    // feature from the desired pose using the next two lines. We will rather compute the
    // desired position of the features from a learning stage.
    // point[i].project(cdMo);
    // vpFeatureBuilder::create(pd[i], point[i]);

    // Compute the current feature at the initial position
    dot[i].setGraphics(true);
    dot[i].initTracking(I);
    vpDisplay::flush(I);
    vpFeatureBuilder::create(p[i], cam, dot[i].getCog());
  }

  for (int i = 0 ; i < 4 ; i++) {
    // Set the feature Z coordinate from the pose
    vpColVector cP;
    point[i].changeFrame(cMo, cP) ;
    p[i].set_Z(cP[2]);

    task.addFeature(p[i], pd[i]);
  }

  vpHomogeneousMatrix wMc, wMo;
  vpSimulatorCamera robot;
  robot.setSamplingTime(0.040);
  robot.getPosition(wMc);
  wMo = wMc * cMo;

  for (; ; ) {
    // From the camera position in the world frame we retrieve the object position
    robot.getPosition(wMc);
    cMo = wMc.inverse() * wMo;

    // Update the scene from the new camera position
    ogre_get_render_image(ogre, background, cMo, I);

    vpDisplay::display(I);

    for (int i = 0 ; i < 4 ; i++) {
      dot[i].track(I);
      vpFeatureBuilder::create(p[i], cam, dot[i].getCog());
    }

    for (int i = 0 ; i < 4 ; i++) {
      // Set the feature Z coordinate from the pose
      vpColVector cP;
      point[i].changeFrame(cMo, cP) ;
      p[i].set_Z(cP[2]);
    }

    vpColVector v = task.computeControlLaw();

    display_trajectory(I, dot, thickness);
    vpServoDisplay::display(task, cam, I, vpColor::green, vpColor::red, thickness+2) ;
    robot.setVelocity(vpRobot::CAMERA_FRAME, v);

    vpDisplay::flush(I);
    if (vpDisplay::getClick(I, false))
      break;

    vpTime::wait( robot.getSamplingTime() * 1000);
  }
  task.kill();
#endif
}