========
Robotics
========

`Unity Robotics Hub <https://github.com/Unity-Technologies/Unity-Robotics-Hub>`_ 

Robotics-Nav2-SLAM-Example
==========================

This is a memo for the example provided `here <https://github.com/Unity-Technologies/Robotics-Nav2-SLAM-Example>`_. 

*Quick start based on ROS installation in a VM (May 2022)*

.. code-block:: bash

    git clone --recurse-submodule git@github.com:Unity-Technologies/Robotics-Nav2-SLAM-Example.git


Configure ROS
-------------

Make sure to have ``ros``, ``python3``, ``pip``, ``rosdep`` and ``colcon`` installed:

.. code-block:: bash

    sudo apt install ros-foxy-desktop python3.8 pip python3-rosdep python3-colcon-common-extensions

Then:

.. code-block:: bash

    python3 -m pip install --no-warn-script-location ipython
    source /opt/ros/${ROS_DISTRO}/setup.bash
    sudo rosdep init
    rosdep update
    rosdep install -yrq --from-paths src --ignore-src --rosdistro $ROS_DISTRO

Finally, go in the ``colcon_ws`` directory and build the packages:

.. code-block:: bash

    colcon build


Configure Unity
---------------

Follow the instruction given in `Setting up the Unity Project <https://github.com/Unity-Technologies/Robotics-Nav2-SLAM-Example/blob/main/readmes/unity_project.md>`_ .

.. note:: 
    
    Everything worked "fine" when converting the project to Unity version ``2021.3.2f1``. Thus you can accept all instructions given by Unity when opening the project. Thought there is some bugs when giving the **2D Goal Pose** command to the robot from RViz. It is not determined if the version of Unity is the cause. 

To find the IP address of the VM type ``ifconfig`` in the terminal. 


Run the example
---------------

In the VM run in the ``colcon_ws`` directory (where the ``install`` folder is created after the build):

.. code-block:: bash

    source install/local_setup.bash
    ros2 launch unity_slam_example unity_slam_example.py

Troubleshooting
---------------

If you encounter the following error when launching the ROS package:

    LookupError: Could not find the resource 'nav2_bringup' of type 'packages'

... rerun this command:

.. code-block:: bash

    rosdep install -yrq --from-paths src --ignore-src --rosdistro $ROS_DISTRO