Method pp_callback

apps/src/pcd_select_object_plane.cpp:435–524

//////////////////////////////////////////////////////////////////// * \brief Point picking callback. This gets called when the user selects * a 3D point on screen (in the PCLVisualizer window) using Shift+click. * * \param[in] event the event that triggered the call */

   * \param[in] event the event that triggered the call
   */
  void
  pp_callback(const visualization::PointPickingEvent& event, void*)
  {
    // Check to see if we got a valid point. Early exit.
    int idx = event.getPointIndex();
    if (idx == -1)
      return;

    pcl::Indices indices(1);
    std::vector<float> distances(1);

    // Get the point that was picked
    PointT picked_pt;
    event.getPoint(picked_pt.x, picked_pt.y, picked_pt.z);

    print_info(stderr,
               "Picked point with index %d, and coordinates %f, %f, %f.\n",
               idx,
               picked_pt.x,
               picked_pt.y,
               picked_pt.z);

    // Add a sphere to it in the PCLVisualizer window
    const std::string sphere_name = "sphere_" + std::to_string(idx);
    cloud_viewer_->addSphere(picked_pt, 0.01, 1.0, 0.0, 0.0, sphere_name);

    // Because VTK/OpenGL stores data without NaN, we lose the 1-1 correspondence, so we
    // must search for the real point
    search_->nearestKSearch(picked_pt, 1, indices, distances);

    // Add some marker to the image
    if (image_viewer_) {
      // Get the [u, v] in pixel coordinates for the ImageViewer. Remember that 0,0 is
      // bottom left.
      std::uint32_t width = search_->getInputCloud()->width,
                    height = search_->getInputCloud()->height;
      int v = height - indices[0] / width, u = indices[0] % width;

      image_viewer_->addCircle(u, v, 5, 1.0, 0.0, 0.0, "circles", 1.0);
      image_viewer_->addFilledRectangle(
          u - 5, u + 5, v - 5, v + 5, 0.0, 1.0, 0.0, "boxes", 0.5);
      image_viewer_->markPoint(
          u, v, visualization::red_color, visualization::blue_color, 10);
    }

    // Segment the region that we're interested in, by employing a two step process:
    //  * first, segment all the planes in the scene, and find the one closest to our
    //  picked point
    //  * then, use euclidean clustering to find the object that we clicked on and
    //  return it
    PlanarRegion<PointT> region;
    segment(picked_pt, indices[0], region, object_);

    // If no region could be determined, exit
    if (region.getContour().empty()) {
      PCL_ERROR("No planar region detected. Please select another point or relax the "
                "thresholds and continue.\n");
      return;