Common Things In All ros2_ws Plugins¶

Structure¶

├── ros2_ws/
│   ├── src/
│   │   ├── yt_tutorial_gazebo_ros/      # ROS 2 Gazebo launch & integration
|   |   |      └──config
|   |   |      └──launch
|   |   |      └──worlds
|   |   |      └──CmakeLists.txt
|   |   |      └──package.xml
│   │   └── tutorial_gazebo_plugins/     # ROS 2 Gazebo plugins
|   |          └──include                # Plugin .hh file
|   |          └──src                    # Plugin .cc file
│   └── ...                               # ROS 2 build, install, log folders
│

ROS2 Gazebo Sim Plugin¶

There are 2 ways:

Using ros-gz-bridge
Using Direct rclcpp in gazebo sim plugin

Naming Convention In The Tutorial¶

<Name> - pure gazebo sim plugin
<Name>TopicWay - using ros2 gz bridge to communicate
<Name>DirectRos - using ros2 rclcpp directly in gazebo sim plugin

launch file¶

GZ_SIM_SYSTEM_PLUGIN_PATH variable is added in the launch file
gz sim launch using ros_gz_sim pkg & 'gz_sim.launch.py launch file

    plugin_pkg_path = FindPackageShare('tutorial_gazebo_plugins')

    set_plugin_path = SetEnvironmentVariable(
    'GZ_SIM_SYSTEM_PLUGIN_PATH',
    PathJoinSubstitution([plugin_pkg_path, 'plugins'])
    )

    world_path = os.path.join(
        get_package_share_directory('yt_tutorial_gazebo_ros'),
        'worlds',
        'move_model_topic_way.sdf',
    )

    ros_gz_sim_share = get_package_share_directory('ros_gz_sim')

    gz_sim = IncludeLaunchDescription(
        PythonLaunchDescriptionSource(
            os.path.join(ros_gz_sim_share, 'launch', 'gz_sim.launch.py')
        ),
        launch_arguments={
            # see next section for -v
            'gz_args': f'-r -v4 {world_path}',
        }.items(),
    )

Build & Run ros2 pkg¶

cd ros2_ws
colcon build --symlink-install

source install/setup.bash
ros2 launch yt_tutorial_gazebo_ros <name>.launch.py