Example: hwdrivers_openni2_2d_icp_slam

C++ example source code:

/* +------------------------------------------------------------------------+
   |                     Mobile Robot Programming Toolkit (MRPT)            |
   |                          https://www.mrpt.org/                         |
   |                                                                        |
   | Copyright (c) 2005-2024, Individual contributors, see AUTHORS file     |
   | See: https://www.mrpt.org/Authors - All rights reserved.               |
   | Released under BSD License. See: https://www.mrpt.org/License          |
   +------------------------------------------------------------------------+ */

#include <mrpt/gui/CDisplayWindow3D.h>
#include <mrpt/hwdrivers/COpenNI2Sensor.h>
#include <mrpt/img/TColor.h>
#include <mrpt/opengl.h>
#include <mrpt/opengl/CPlanarLaserScan.h>  // This class is in mrpt-maps
#include <mrpt/system/CTicTac.h>

#include <iostream>

using namespace mrpt;
using namespace mrpt::obs;
using namespace mrpt::opengl;
using namespace mrpt::hwdrivers;
using namespace mrpt::img;
using namespace std;

const float vert_FOV = 4.0_deg;

// This demo records from an OpenNI2 device, convert observations to 2D scans
// and runs 2d-icp-slam with them.

int main(int argc, char** argv)
{
  try
  {
    if (argc > 2)
    {
      cerr << "Usage: " << argv[0] << " <sensor_id/sensor_serial\n";
      cerr << "Example: " << argv[0] << " 0 \n";
      return 1;
    }

    // const unsigned sensor_id = 0;
    COpenNI2Sensor rgbd_sensor;
    // rgbd_sensor.loadConfig_sensorSpecific(const
    // mrpt::config::CConfigFileBase &configSource, const std::string
    // &iniSection );

    unsigned sensor_id_or_serial = 0;
    if (argc == 2)
    {
      sensor_id_or_serial = atoi(argv[1]);
      if (sensor_id_or_serial > 10)
        rgbd_sensor.setSerialToOpen(sensor_id_or_serial);
      else
        rgbd_sensor.setSensorIDToOpen(sensor_id_or_serial);
    }

    // Open:
    // cout << "Calling COpenNI2Sensor::initialize()...";
    rgbd_sensor.initialize();

    if (rgbd_sensor.getNumDevices() == 0) return 0;

    cout << "OK " << rgbd_sensor.getNumDevices() << " available devices." << endl;
    cout << "\nUse device " << sensor_id_or_serial << endl << endl;

    // Create window and prepare OpenGL object in the scene:
    // --------------------------------------------------------
    mrpt::gui::CDisplayWindow3D win3D("OpenNI2 3D view", 800, 600);

    win3D.setCameraAzimuthDeg(140);
    win3D.setCameraElevationDeg(20);
    win3D.setCameraZoom(8.0);
    win3D.setFOV(90);
    win3D.setCameraPointingToPoint(2.5, 0, 0);

    mrpt::opengl::CPointCloudColoured::Ptr gl_points = mrpt::opengl::CPointCloudColoured::Create();
    gl_points->setPointSize(2.5);

    // The 2D "laser scan" OpenGL object:
    mrpt::opengl::CPlanarLaserScan::Ptr gl_2d_scan = mrpt::opengl::CPlanarLaserScan::Create();
    gl_2d_scan->enablePoints(true);
    gl_2d_scan->enableLine(true);
    gl_2d_scan->enableSurface(true);
    gl_2d_scan->setSurfaceColor(0, 0, 1, 0.3);  // RGBA

    opengl::Viewport::Ptr viewInt;  // Extra viewports for the RGB images.
    {
      mrpt::opengl::Scene::Ptr& scene = win3D.get3DSceneAndLock();

      // Create the Opengl object for the point cloud:
      scene->insert(gl_points);
      scene->insert(mrpt::opengl::CGridPlaneXY::Create());
      scene->insert(mrpt::opengl::stock_objects::CornerXYZ());
      scene->insert(gl_2d_scan);

      const double aspect_ratio = 480.0 / 640.0;
      const int VW_WIDTH = 400;  // Size of the viewport into the window, in pixel units.
      const int VW_HEIGHT = aspect_ratio * VW_WIDTH;

      // Create an extra opengl viewport for the RGB image:
      viewInt = scene->createViewport("view2d_int");
      viewInt->setViewportPosition(5, 30, VW_WIDTH, VW_HEIGHT);
      win3D.addTextMessage(10, 30 + VW_HEIGHT + 10, "Intensity data", 2);

      win3D.addTextMessage(5, 5, "'o'/'i'-zoom out/in, ESC: quit", 110);

      win3D.unlockAccess3DScene();
      win3D.repaint();
    }

    //                          Grab frames continuously and show
    //========================================================================================

    bool bObs = false, bError = true;
    mrpt::system::TTimeStamp last_obs_tim = INVALID_TIMESTAMP;

    while (!win3D.keyHit())  // Push any key to exit // win3D.isOpen()
    {
      //    cout << "Get new observation\n";
      CObservation3DRangeScan::Ptr newObs = CObservation3DRangeScan::Create();
      rgbd_sensor.getNextObservation(*newObs, bObs, bError);

      CObservation2DRangeScan::Ptr obs_2d;  // The equivalent 2D scan

      if (bObs && !bError && newObs && newObs->timestamp != INVALID_TIMESTAMP &&
          newObs->timestamp != last_obs_tim)
      {
        // It IS a new observation:
        last_obs_tim = newObs->timestamp;

        // Convert ranges to an equivalent 2D "fake laser" scan:
        if (newObs->hasRangeImage)
        {
          // Convert to scan:
          obs_2d = CObservation2DRangeScan::Create();

          T3DPointsTo2DScanParams p2s;
          p2s.angle_sup = .5f * vert_FOV;
          p2s.angle_inf = .5f * vert_FOV;
          p2s.sensorLabel = "KINECT_2D_SCAN";
          newObs->convertTo2DScan(*obs_2d, p2s);
        }

        // Update visualization ---------------------------------------

        win3D.get3DSceneAndLock();

        // Estimated grabbing rate:
        win3D.addTextMessage(
            -350, -13,
            format("Timestamp: %s", mrpt::system::dateTimeLocalToString(last_obs_tim).c_str()),
            100);

        // Show intensity image:
        if (newObs->hasIntensityImage)
        {
          viewInt->setImageView(newObs->intensityImage);  // This is not "_fast" since
                                                          // the intensity image may be
                                                          // needed later on.
        }
        win3D.unlockAccess3DScene();

        // -------------------------------------------------------
        //           Create 3D points from RGB+D data
        //
        // There are several methods to do this.
        //  Switch the #if's to select among the options:
        // See also:
        // https://www.mrpt.org/Generating_3D_point_clouds_from_RGB_D_observations
        // -------------------------------------------------------
        if (newObs->hasRangeImage)
        {
          // Pathway: RGB+D --> XYZ+RGB opengl
          win3D.get3DSceneAndLock();
          mrpt::obs::T3DPointsProjectionParams pp;
          pp.takeIntoAccountSensorPoseOnRobot = false;
          newObs->unprojectInto(*gl_points, pp /* without obs.sensorPose */);
          win3D.unlockAccess3DScene();
        }

        // And load scan in the OpenGL object:
        gl_2d_scan->setScan(*obs_2d);

        win3D.repaint();
      }  // end update visualization:
    }

    cout << "\nClosing RGBD sensor...\n";

    return 0;
  }
  catch (const std::exception& e)
  {
    std::cerr << "MRPT error: " << mrpt::exception_to_str(e) << std::endl;
    return -1;
  }
}