.. _realsense:

RealSense with Open3D
=====================

RealSense (``librealsense`` SDK v2) is integrated into Open3D (v0.12+) and you
can use it through both C++ and Python APIs without a separate ``librealsense``
SDK installation on Linux, macOS and Windows. Older versions of Open3D support
RealSense through a separate install of ``librealsense`` SDK v1 and
``pyrealsense``.

Obtaining Open3D with RealSense support
---------------------------------------

Python
^^^^^^
Install Open3D from PyPI (a virtual environment is recommended):

.. code-block:: sh

    pip install open3d

Compile from source (C++)
^^^^^^^^^^^^^^^^^^^^^^^^^
To build Open3D from source with RealSense support, set
``BUILD_LIBREALSENSE=ON`` at CMake config step. You can add other configuration
options as well (e.g.: ``BUILD_GUI=ON`` and ``BUILD_PYTHON_MODULE=ON`` may be
useful).

.. code-block:: sh

    cmake -D BUILD_LIBREALSENSE=ON -D <OTHER_FLAGS> /path/to/Open3D/source/

Reading from RealSense bag files
--------------------------------

Sample RealSense bag files
^^^^^^^^^^^^^^^^^^^^^^^^^^

You con download sample RealSense bag datasets with this script::

    python examples/python/reconstruction_system/scripts/download_dataset.py L515_test

Check the script for more RS bag datasets.

Here is a C++ code snippet that shows how to read a RealSense bag file recorded
with Open3D or the ``realsense-viewer``. Note that general ROSbag files are not
supported. See more details and available functionality (such as getting
timestamps, aligning the depth stream to the color stream and getting intrinsic
calibration) in the C++ API in the `RSBagReader documentation
<../../cpp_api/classopen3d_1_1t_1_1io_1_1_r_s_bag_reader.html>`_

.. code-block:: C++

    #include <open3d/open3d.hpp>
    using namespace open3d;
    t::io::RSBagReader bag_reader;
    bag_reader.Open(bag_filename);
    auto im_rgbd = bag_reader.NextFrame();
    while (!bag_reader.IsEOF()) {
        // process im_rgbd.depth_ and im_rgbd.color_
        im_rgbd = bag_reader.NextFrame();
    }
    bag_reader.Close();

Here is the corresponding Python code:

.. code-block:: Python

    import open3d as o3d
    bag_reader = o3d.t.io.RSBagReader()
    bag_reader.open(bag_filename)
    im_rgbd = bag_reader.next_frame()
    while not bag_reader.is_eof():
        # process im_rgbd.depth and im_rgbd.color
        im_rgbd = bag_reader.next_frame()

    bag_reader.close()

Examples
^^^^^^^^

C++ RS bag file viewer
""""""""""""""""""""""
This C++ example that plays back the color and depth streams from a RealSense
bag file. It also prints out metadata about the video streams in the file. Press
[SPACE] to pause/resume and [ESC] to exit.::

    make RealSenseBagReader
    bin/examples/RealSenseBagReader --input L515_test.bag

.. image:: https://storage.googleapis.com/open3d-bin/docs/images/RSbagviewer.jpg
    :width: 800px
    :align: center
    :alt: RealSenseBagReader example

Running the scene reconstruction pipeline
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
You can provide an RS bag file directly to the reconstruction pipeline and
colormap optimization pipelines. It will be automatically converted to a
directory of depth and color frames and the camera intrinsics. Edit the
`examples/python/reconstruction_system/config/realsense.json` file with the path
to your RS bag file and leave `path_intrinsic` empty. Update other configuration
parameters if needed (see the reconstruction pipeline documentation for more
details, including other required packages)::

    cd examples/python/reconstruction_system/
    python run_system.py --make --register --refine --integrate config/realsense.json
    python color_map_optimization_for_reconstruction_system.py  --config config/realsense.json

The reconstruction result below was obtained with the ``L515_JackJack`` dataset
with the configuration changes::

    "path_dataset": "/path/to/downloaded/L515_JackJack.bag"
    "depth_max": 0.85,
    "tsdf_cubic_size": 0.75,
    "voxel_size": 0.025,
    "depth_diff_max": 0.03

.. raw:: html

   <video width="800" controls
   src="https://storage.googleapis.com/open3d-bin/docs/images/JackJack_colormap_opt_result.mp4"
   type="video/mp4" autoplay>
   Scene reconstruction sample result with RealSense bag input data
   </video>

RealSense camera configuration, live capture, processing and recording
----------------------------------------------------------------------

RealSense camera discovery
^^^^^^^^^^^^^^^^^^^^^^^^^^

You can list all RealSense devices connected to the system and get their
capabilities (supported resolutions, frame rates, etc.) with the code snippet
below.

.. code-block:: C++

    #include <open3d/open3d.hpp>
    open3d::t::io::RealSenseSensor::ListDevices();

.. code-block:: Python

    import open3d as o3d
    o3d.t.io.RealSenseSensor.list_devices()

Here is sample output when only one L515 camera is connected::

    [Open3D INFO] [0] Intel RealSense L515: f0141095
    [Open3D INFO] 	color_format: [RS2_FORMAT_BGR8 | RS2_FORMAT_BGRA8 | RS2_FORMAT_RGB8 | RS2_FORMAT_RGBA8 | RS2_FORMAT_Y16 | RS2_FORMAT_YUYV]
    [Open3D INFO] 	color_resolution: [1280,720 | 1920,1080 | 960,540]
    [Open3D INFO] 	color_fps: [15 | 30 | 6 | 60]
    [Open3D INFO] 	depth_format: [RS2_FORMAT_Z16]
    [Open3D INFO] 	depth_resolution: [1024,768 | 320,240 | 640,480]
    [Open3D INFO] 	depth_fps: [30]
    [Open3D INFO] 	visual_preset: [RS2_L500_VISUAL_PRESET_CUSTOM | RS2_L500_VISUAL_PRESET_DEFAULT | RS2_L500_VISUAL_PRESET_LOW_AMBIENT | RS2_L500_VISUAL_PRESET_MAX_RANGE | RS2_L500_VISUAL_PRESET_NO_AMBIENT | RS2_L500_VISUAL_PRESET_SHORT_RANGE]
    [Open3D INFO] Open3D only supports synchronized color and depth capture (color_fps = depth_fps).

This data can also be obtained programmatically to configure a camera based on
custom specifications (e.g.: resolution less than 720p) and to independently
configure multiple cameras.

RealSense camera configuration
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

RealSense cameras can be configured with a simple ``json`` configuration file.
See `RealSense documentation
<https://intelrealsense.github.io/librealsense/doxygen/rs__option_8h.html>`_ for
the set of configuration values. Supported configuration options will be depend
on the device and other chosen options. Here are the options supported by
Open3D:

* **serial**: Pick a specific device, leave empty to pick the first available
  device.
* **color_format**:  Pixel format for color frames.
* **color_resolution**: (width, height): Leave 0 to let RealSense pick a
  supported width or height.
* **depth_format**: Pixel format for depth frames.
* **depth_resolution**: (width, height): Leave 0 to let RealSense pick a
  supported width or height.
* **fps**: Common frame rate for both depth and color streams. Leave 0 to let
  RealSense pick a supported frame rate.
* **visual_preset**: Controls depth computation on the device. Supported values
  are specific to product line (SR300, RS400, L500). Leave empty to pick the
  default.

Here is an example ``json`` configuration file to capture 30fps, 540p color and
480p depth video from any connected RealSense camera. The video width is picked
by RealSense. We also set the ``visual_preset`` to
``RS2_L500_VISUAL_PRESET_MAX_RANGE`` to better capture far away objects.

.. code-block:: json

  {
      "serial": "",
      "color_format": "RS2_FORMAT_RGB8",
      "color_resolution": "0,540",
      "depth_format": "RS2_FORMAT_Z16",
      "depth_resolution": "0,480",
      "fps": "30",
      "visual_preset": "RS2_L500_VISUAL_PRESET_MAX_RANGE"
   }

RealSense camera capture, processing and recording
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

The following code snippets show how to capture live RGBD video from a RealSense
camera. They capture the first 150 frames and also record them to an RS bag
file. The bag file can be played back with Open3D tools, realsense-viewer. You
can also use ROS tools such as `rosbag <http://wiki.ros.org/rosbag>`_, `rqt_bag
<http://wiki.ros.org/rqt_bag>`_ and `rviz <https://wiki.ros.org/rviz>`_ to
examine, play and modify the bag file. You can adapt the snippets to your needs
by processing or displaying the frames after capture.

.. code-block:: C++

    #include <open3d/open3d.hpp>
    open3d::t::io::RealSenseSensorConfig rs_cfg;
    open3d::io::ReadIJsonConvertible(config_filename, rs_cfg);
    RealSenseSensor rs;
    rs.InitSensor(rs_cfg, 0, bag_filename);
    rs.StartCapture(true);  // true: start recording with capture
    for(size_t fid = 0; fid<150; ++fid) {
        im_rgbd = rs.CaptureFrame(true, true);  // wait for frames and align them
        // process im_rgbd.depth_ and im_rgbd.color_
    }
    rs.StopCapture();

.. code-block:: Python

    import json
    import open3d as o3d
    with open(config_filename) as cf:
        rs_cfg = o3d.t.io.RealSenseSensorConfig(json.load(cf))

    rs = o3d.t.io.RealSenseSensor()
    rs.init_sensor(rs_cfg, 0, bag_filename)
    rs.start_capture(True)  # true: start recording with capture
    for fid in range(150):
        im_rgbd = rs.capture_frame(True, True)  # wait for frames and align them
        # process im_rgbd.depth and im_rgbd.color

    rs.stop_capture()

Note that for any real time application such as live capture and processing, it
is important to complete frame processing in the frame interval (~33ms for 30fps
recording). You may experience frame drops otherwise. For high resolution
capture, you can defer frame alignment by setting ``align_depth_to_color=false``
during capture and performing it while reading the bad file instead.

This is a complete C++ example that shows visualizing live capture and recording
to a bag file. The recording can be paused / resumed with [SPACE]. Use [ESC] to
stop capture and quit. You can download the 
`rs_default_config.json <https://github.com/isl-org/open3d_downloads/releases/download/20220301-data/rs_default_config.json>`_ 
and use this example to capture your own dataset::

        make RealSenseRecorder
        bin/examples/RealSenseRecorder --config ../examples/test_data/rs_default_config.json --record test_data.bag

.. image:: https://storage.googleapis.com/open3d-bin/docs/images/RealSenseRecorder.jpg
    :width: 800px
    :align: center
    :alt: RealSenseRecorder example
