C++ examples

The source code for all these C++ examples can be found under MRPT/mrpt_examples_cpp. They are built along with MRPT when MRPT_BUILD_EXAMPLES is enabled in CMake.

Python examples are here. A machine-readable index of all examples is available in examples.json.

3D graphics and GUIs

gui_capture_render_to_img_example

Saves the rendered frames of a 3D window (mrpt::gui::CDisplayWindow3D) to image files.

gui

gui_depth_camera_distortion

Interactive GUI to explore the effect of camera intrinsic and distortion parameters on a 3D depth camera point cloud.

gui

gui_display3D_custom_render

A 3D window (mrpt::gui::CDisplayWindow3D) with a custom render callback that updates the scene before each frame.

gui

gui_display3D_example

A tour of mrpt::gui::CDisplayWindow3D: 3D objects, text, mouse picking and camera control.

gui

gui_display_plots

This example demonstrates mrpt::gui::CDisplayWindowPlots capabilities to show MATLAB/Octave-like plots directly from your C++ program.

gui

gui_fbo_render_example

Renders a 3D scene offscreen with mrpt::opengl::CFBORender and shows the result as an image.

gui

gui_gravity3d_example

Animated 3D rendering of a simple gravitational simulation of many spheres.

gui

gui_nanogui_demo

A 3D scene inside a window with nanogui controls (buttons, sliders, text boxes), with mrpt::gui::CDisplayWindowGUI.

gui

gui_text_fonts_example

Draws text with the bitmap fonts available in mrpt::img::CCanvas.

gui

gui_windows_events

Handles keyboard, mouse and resize events from 2D, 3D and plot windows with the observer pattern.

gui

imgui_mrpt_example

An MRPT 3D scene embedded in a Dear ImGui application with mrpt::imgui::CImGuiSceneView.

gui

opengl_custom_shaders_demo

This example demonstrates how to install a custom OpenGL shader replacing one of MRPT default ones.

gui

opengl_multithread_rendering

Renders 3D scenes offscreen from several threads at once with mrpt::opengl::CFBORender.

gui

opengl_normal_maps

Normal maps on textured planes: two brick walls side by side, with and without a normal map, lit by a grazing point light.

gui

opengl_objects_demo

A gallery of all MRPT 3D object classes (mrpt::viz): boxes, arrows, meshes, point clouds, text, and more.

gui

opengl_skybox_example

A skybox (mrpt::viz::CSkyBox) around a 3D scene, with textures downloaded on the fly.

gui

opengl_ssao_demo

Interactive demo of Screen-Space Ambient Occlusion (SSAO) and multiple light sources, including a moving point light that casts shadows.

gui

opengl_offscreen_render_example

Renders a 3D scene loaded from a file into an image, offscreen, with mrpt::opengl::CFBORender.

opengl_texture_sizes_test

Tests textured planes with images of many different sizes, including non-power-of-two ones.

gui

opengl_video_demo

Shows live camera images as a texture inside a 3D scene.

gui

opengl_video_viewport_demo

Shows live camera images in a 2D viewport overlaid on a 3D scene.

gui

Maps

maps_gmrf_map_example

Estimates a gas concentration map from sparse readings with a Gaussian Markov Random Field (mrpt::maps::CGasConcentrationGridMap2D).

gui

maps_gridmap3D_simple

Builds a 3D occupancy grid map (mrpt::maps::COccupancyGridMap3D) from a laser scan and shows it.

gui

maps_gridmap_voronoi_example

Computes the Voronoi diagram of the free space of a 2D occupancy grid map.

gui

maps_octomap_simple

Builds an octree-based 3D occupancy map (mrpt::maps::COctoMap) from a laser scan and shows it.

gui

maps_ransac_data_association

Data association between two sets of 2D landmarks with RANSAC, estimating the relative pose.

gui

maps_voxelmap_from_tum_dataset

Builds a colored voxel map (mrpt::maps::CVoxelMapRGB) from RGB-D frames of a TUM dataset sequence.

dataset gui

maps_voxelmap_simple

Builds a sparse 3D voxel occupancy map (mrpt::maps::CVoxelMap) from a laser scan and shows it.

gui

maps_gridmap_benchmark

Benchmarks the insertion of laser scans into 2D occupancy grid maps.

maps_gridmap_likelihood_characterization

Evaluates the observation likelihood of a laser scan in a 2D occupancy grid map over a grid of poses.

maps_laser_projection_in_images_example

Projects 2D laser scan points onto camera images, from a rawlog with both kinds of observations.

dataset gui

maps_observer_pattern_example

Subscribes to change events of a metric map (mrpt::maps::CSimplePointsMap) with the observer pattern.

SLAM, Bayesian filtering and graph-SLAM

bayes_tracking_example

This example illustrates how to implement an Extended Kalman Filter (EKF) and a particle filter (PF) using mrpt::bayes classes, for the problem of tracking a 2D mobile target with state space being its location and its velocity vector.

gui

graphslam_example

Optimizes a noisy 2D or 3D graph of poses with Levenberg-Marquardt graph-SLAM (mrpt::graphslam::optimize_graph_spa_levmarq()).

gui

slam_icp3d_simple_example

Aligns two 3D point clouds with ICP (mrpt::slam::CICP) and shows them before and after alignment.

gui

slam_icp_simple_example

Aligns two 2D laser scans with ICP (mrpt::slam::CICP) and plots the result.

gui

bayes_rejection_sampling_example

Rejection sampling of a 2D robot pose from range-bearing measurements to a landmark, with mrpt::bayes::CRejectionSamplingCapable.

bayes_resampling_example

Compares the particle filter resampling algorithms in mrpt::bayes::CParticleFilterCapable (multinomial, residual, stratified, systematic).

slam_range_only_localization_rej_sampling_example

Range-only localization from beacon ranges with rejection sampling (mrpt::slam::CRejectionSamplingRangeOnlyLocalization).

Math, poses and geometry

math_leastsquares_example

Fits a line to noisy 2D points by linear least squares (mrpt::math::leastSquareLinearFit()) and plots the result.

gui

math_model_search_example

Robust fitting of a 3D plane to a noisy point cloud with the generic model search (RANSAC or genetic) in mrpt::math::ModelSearch.

gui

math_polygon_intersection

Example for the C++ function mrpt::math::intersect(const TPolygon2D& subject, const TPolygon2D& clipping) for polygon clipping or intersection using the Sutherland-Hodgman algorithm.

gui

math_polygon_split

Splits a 2D polygon into convex polygons with mrpt::math::splitInConvexComponents().

gui

math_polyhedron_intersection_example

Intersections between 3D polyhedra and other geometric objects, shown in an animated 3D view.

gui

math_ransac_examples

Detection of multiple 3D planes and 2D lines in noisy points with RANSAC (mrpt::math::ransac_detect_3D_planes()).

gui

math_ransac_plane3d_example

This example shows how to use MRPT’s RANSAC C++ template to detect planes from a 3D point cloud given as a matrix (each row is a point).

gui

math_ransac_plane3d_example2

This example shows how to use MRPT’s RANSAC C++ template to detect planes from a 3D point cloud given as a mrpt::maps::CPointsMap.

gui

math_slerp_example

Interpolation between two 3D poses with SLERP (mrpt::math::slerp()), shown as an animation.

gui

math_spline_interpolation

Cubic spline interpolation of scalar functions and of 3D pose trajectories (mrpt::poses::CPose3DInterpolator).

gui

poses_sog_merge_example

Example of how to merge overlapping modes of a Sum Of Gaussians (SOG) representation of a pose, in this case, a SE(2) SoG probability distribution function.

gui

poses_unscented_transform_example

Propagates Gaussian uncertainty through nonlinear functions with the unscented transform, linearization and Monte Carlo.

gui

random_examples

MRPT includes a C++ platform-independent implementation of the MT19937 algorithm for generating high-quality pseudo-random numbers. The following example demonstrates:

gui

math_matrix_example

Tour of MRPT matrices: initialization, fixed-size and dynamic matrices, Cholesky and other operations.

math_optimize_lm_example

Fits a model to data with the generic Levenberg-Marquardt optimizer in mrpt::math::CLevenbergMarquardt.

poses_geometry_3D_example

Composition and inverse composition of 2D and 3D poses and points with mrpt::poses classes.

poses_pdfs_example

Operations with probability distributions of poses and points: composition, inverse and uncertainty propagation.

poses_quaternions_example

Quaternions and their conversion to and from 3D rotations with mrpt::math::CQuaternion and mrpt::poses::CPose3DQuat.

poses_se3_lie_example

Lie group operations on SE(3): exponential and logarithm maps and Jacobians, with mrpt::poses::Lie::SE.

topography_coordinate_conversion_example

Conversions between geodetic, geocentric (ECEF), ENU and UTM coordinates with mrpt::topography.

topography_gps_coords_example

Converts GPS (geodetic) coordinates into local ENU and geocentric coordinates with mrpt::topography.

Images

img_basic_example

Basic image operations with mrpt::img::CImage: loading, color conversions, scaling and display.

gui

img_convolution_fft

Image convolution in the frequency domain with 2D FFTs.

gui

img_gauss_filtering_example

Gaussian filtering of images with mrpt::img::CImage::filterGaussian().

gui

img_fft_example

2D FFT of real and complex matrices and of images with mrpt::math::dft2_real() and related functions.

Sensors, observations and datasets

obs_motion_model_demo

Replays the odometry of a rawlog and shows the uncertainty of the probabilistic 2D motion models (mrpt::obs::CActionRobotMovement2D) as particle clouds.

gui

hwdrivers_camera_capture_dialog

Opens a dialog to select a camera source and shows its live images with mrpt::hwdrivers::CCameraSensor.

hardware gui

hwdrivers_capture_video_dc1394

Grabs images from an IEEE1394 (FireWire) camera with mrpt::hwdrivers::CImageGrabber_dc1394.

hardware gui

hwdrivers_capture_video_ffmpeg

Reads video from a file, camera or network stream with mrpt::hwdrivers::CFFMPEG_InputStream.

gui

hwdrivers_capture_video_flycapture2

Grabs images from a Point Grey (FLIR) camera with mrpt::hwdrivers::CImageGrabber_FlyCapture2.

hardware gui

hwdrivers_capture_video_flycapture2_stereo

Grabs synchronized stereo images from two Point Grey (FLIR) cameras with mrpt::hwdrivers::CImageGrabber_FlyCapture2.

hardware gui

hwdrivers_capture_video_opencv

Grabs images from a webcam or video file with mrpt::hwdrivers::CImageGrabber_OpenCV.

gui

hwdrivers_enumerate_cameras1394

Lists the IEEE1394 (FireWire) cameras connected to the computer.

hardware

hwdrivers_gps_example

Reads and parses NMEA or binary data from a GNSS (GPS) receiver with mrpt::hwdrivers::CGPSInterface.

hardware

hwdrivers_hokuyo_example

Reads 2D laser scans from a Hokuyo scanner with mrpt::hwdrivers::CHokuyoURG and plots them.

hardware gui

hwdrivers_joystick_example

Reads the axes and buttons of a joystick or gamepad with mrpt::hwdrivers::CJoystick.

hardware

hwdrivers_kinect_online_offline_example

Grabs RGB-D frames from a Kinect, or replays them from a rawlog file, and shows the 3D point cloud.

gui

hwdrivers_kinect_to_2d_scan_example

Converts the depth images of a Kinect into 2D laser-like scans.

hardware gui

hwdrivers_mynteye_icp

Aligns consecutive point clouds from a MYNT EYE depth camera with ICP.

hardware gui

hwdrivers_ntrip_client_example

Connects to an NTRIP caster to receive GNSS RTK corrections with mrpt::hwdrivers::CNTRIPClient.

hardware

hwdrivers_openni2_2d_icp_slam

2D ICP-SLAM from laser-like scans computed from an OpenNI2 RGB-D camera.

hardware gui

hwdrivers_openni2_driver_demo

Grabs RGB-D frames from an OpenNI2 camera and shows the images and the 3D point cloud.

hardware gui

hwdrivers_phidget_proximity_example

Reads Phidget proximity sensors through a Phidget interface kit.

hardware

hwdrivers_robopeaklidar_example

Reads 2D laser scans from a RoboPeak (Slamtec) RPLIDAR with mrpt::hwdrivers::CRoboPeakLidar.

hardware

hwdrivers_sick_eth_example

Reads 2D laser scans from a SICK LMS100 (Ethernet) and shows them in 3D.

hardware gui

hwdrivers_sick_serial_example

Reads 2D laser scans from a SICK LMS2xx (serial port) and plots them.

hardware gui

hwdrivers_taobotics_imu

This example demonstrates the C++ API to read from Taobotics IMU sensors (e.g. ROS IMU HFI A9).

hardware gui

kitti_dataset2rawlog

Converts a KITTI stereo dataset sequence into an MRPT rawlog file.

dataset

obs_mox_model_rawlog

Applies a dynamic model of metal oxide (MOX) gas sensors to the readings in a rawlog file.

rgbd_dataset2rawlog

Converts a TUM RGB-D dataset sequence into an MRPT rawlog file.

dataset

Core, containers, I/O and system

system_control_rate_timer_example

Runs a loop at a fixed rate with mrpt::system::CControlledRateTimer, and plots the achieved rate.

gui

system_progress_bar

Shows a text progress bar in the console with mrpt::system::progress().

comms_ftdi_usb_enumerate_example

Lists the FTDI USB devices connected to the computer, with mrpt::comms::CInterfaceFTDI.

hardware

comms_http_client

Downloads a web page with the HTTP client functions in mrpt::comms::net::http_get().

comms_nodelets_example

Publish/subscribe communication between threads in the same process with mrpt::comms::nodelets.

comms_serial_port_example

Writes to and reads from a serial port with mrpt::comms::CSerialPort.

hardware

comms_socket_example

A TCP server and client exchanging serialized MRPT objects with mrpt::comms::CServerTCPSocket and mrpt::comms::CClientTCPSocket.

containers_params_by_name

Passing a variable set of named parameters to a function with mrpt::containers::yaml.

containers_yaml_example

Examples of use for the YAML C++17 container in mrpt::containers::yaml.

core_backtrace_example

Captures and prints the current call stack with mrpt::callStackBackTrace().

core_exceptions_example

Examples of use for MRPT exceptions macros.

io_compress_example

Compresses and decompresses data in memory and in files with gzip (mrpt::io::zip).

io_pipes_example

Sends serialized objects between two threads through an operating system pipe (mrpt::io::CPipe).

rtti_example1

Run-time type information (RTTI) for user classes with mrpt::rtti: type checks and class factories.

serialization_json_example

Serializes MRPT objects to and from JSON with mrpt::serialization::CSchemeArchive.

serialization_stl

Serializes STL containers (vectors, maps, sets, …) to and from files with mrpt::serialization::CArchive.

serialization_variant_example

Serializes and deserializes std::variant objects through a pipe between two threads.

system_datetime_example

Timestamps, time differences and date and time formatting with mrpt::system and mrpt::Clock.

system_directory_explorer_example

Lists the files in a directory, recursively, with mrpt::system::CDirectoryExplorer.

system_dirs_files_manipulation

Creates, renames and deletes files and directories with mrpt::system filesystem functions.

system_file_system_watcher

Watches a directory for file changes with mrpt::system::CFileSystemWatcher.

typemeta_StaticString

Compile-time string concatenation and number to string conversion with mrpt::typemeta.

typemeta_TEnumType

Converting enum values to and from strings with mrpt::typemeta::TEnumType.

typemeta_TTypeName

Compile-time type names, including STL containers, with mrpt::typemeta::TTypeName.