Composition and Bridge Updates (#528)

* Composition and Bridge Updates

Signed-off-by: Aarav Gupta <[email protected]>

* Update composition_options.png

Signed-off-by: Aarav Gupta <[email protected]>

* Add documentation for spawning a model alongside launch ros_gz_bridge

Signed-off-by: Aarav Gupta <[email protected]>

* Undo changes made to comopsition_options.png

Has been done in #531

Signed-off-by: Aarav Gupta <[email protected]>

---------

Signed-off-by: Aarav Gupta <[email protected]>
Signed-off-by: Aarav Gupta <[email protected]>

Author: Amronos

harmonic/ros2_integration.md

@@ -65,21 +65,18 @@ for a valid configuration file.
 
 The package `ros_gz_bridge` contains a launch file named
 `ros_gz_bridge.launch.py`. You can use it to start a ROS 2 and Gazebo bridge.
-Here's an example:
 
-Note: If you run the bridge as a standalone node with composition enabled,
-you'll need to create a container first.
+Here's an example:
 ```bash
-ros2 run rclcpp_components component_container --ros-args -r __node:=ros_gz_container
+ros2 launch ros_gz_bridge ros_gz_bridge.launch.py bridge_name:=ros_gz_bridge config_file:=<path_to_your_YAML_file>
 ```
 
-Alternatively, if an existing container is already running, you can pass its name
-when launching the bridge using the `container_name` parameter.
-
-And now, the container will load your bridge with:
+Launching with composition:
 ```bash
-ros2 launch ros_gz_bridge ros_gz_bridge.launch.py bridge_name:=ros_gz_bridge use_composition:=True config_file:=<path_to_your_YAML_file>
+ros2 launch ros_gz_bridge ros_gz_bridge.launch.py bridge_name:=ros_gz_bridge config_file:=<path_to_your_YAML_file> use_composition:=True create_own_container:=True
 ```
+Alternatively, if an existing container is already running, you can pass its name
+when launching the bridge using the `container_name` parameter. More info about composition can be viewed [here](ros2_overview#composition)
 
 Check [this block](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_bridge/launch/ros_gz_bridge.launch.py#L27-L34)
 from the source code to know all the different parameters accepted by this

harmonic/ros2_launch_gazebo.md

@@ -93,13 +93,6 @@ def generate_launch_description():
                 'on_exit_shutdown': 'True'
             }.items(),
         ),
-        Node(
-            package='ros_gz_bridge',
-            executable='parameter_bridge',
-            arguments=[],
-            remappings=[],
-            output='screen'
-        ),
     ])
 ```
 
@@ -129,3 +122,19 @@ def generate_launch_description():
 
     return ld
 ```
+
+
+## Launching with ros_gz_bridge
+
+An example launch file for XML can be viewed [here](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/ros_gz_sim.launch)
+An example launch file for Python can be viewed [here](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/ros_gz_sim.launch.py)
+
+Example command for directly using these launch files from the terminal:
+```bash
+ros2 launch ros_gz_sim ros_gz_sim.launch.py world_sdf_file:=empty.sdf bridge_name:=ros_gz_bridge config_file:=<path_to_your_YAML_file> use_composition:=True create_own_container:=True
+```
+
+In the above launch files you may notice that the `create_own_container` argument for `ros_gz_bridge` is hardcoded to `False`. This has been done to prevent two duplicate containers from getting created (one for `gz_server` and another one for `ros_gz_bridge`), and instead make `ros_gz_bridge` use the container created by `gz_server`. More info about this can be viewed [here](https://github.com/gazebosim/ros_gz/pull/620#issue-2595570189)
+
+More info about `ros_gz_bridge` can be viewed [here](ros2_integration).
+More info about composition can be viewed [here](ros2_overview#composition).

harmonic/ros2_overview.md

@@ -64,7 +64,7 @@ diagram is still using composition but the launch file doesn't start the
 container directly. This setup by itself will not work until you start an
 external ROS container (manually or via a separate launch file).
 
-You can learn more about ROS composition in [this tutorial](https://docs.ros.org/en/galactic/Tutorials/Intermediate/Composition.html).
+You can learn more about ROS composition in [this tutorial](https://docs.ros.org/en/jazzy/Tutorials/Intermediate/Composition.html).
 
 ## What's next?
 

harmonic/ros2_spawn_model.md

@@ -8,14 +8,14 @@ we have provided the following mechanisms:
 *Currently only available in Rolling.*
 
 The package `ros_gz_sim` contains a launch file named
-`ros_gz_spawn_model.launch.py`. You can use it to spawn a new model into an
+`gz_spawn_model.launch.py`. You can use it to spawn a new model into an
 existing simulation. Here's an example:
 
 ```bash
-ros2 launch ros_gz_sim ros_gz_spawn_model.launch.py world:=empty file:=$(ros2 pkg prefix --share ros_gz_sim_demos)/models/vehicle/model.sdf entity_name:=my_vehicle x:=5.0 y:=5.0 z:=0.5
+ros2 launch ros_gz_sim gz_spawn_model.launch.py world:=empty file:=$(ros2 pkg prefix --share ros_gz_sim_demos)/models/vehicle/model.sdf entity_name:=my_vehicle x:=5.0 y:=5.0 z:=0.5
 ```
 
-Check [this block](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/ros_gz_spawn_model.launch.py#L26-L45)
+Check [this block](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/gz_spawn_model.launch.py#L26-L45)
 from the source code to know all the different parameters accepted by this
 launch file.
 
@@ -60,3 +60,16 @@ within this tag. Here's an example:
 In this case the `<gz_spawn_model>` parameters are read from the command line.
 That's an option but not strictly necessary as you could decide to hardcode some
 of the values or not even use all of the parameters.
+
+
+## Spawning a model alongside launching ros_gz_bridge
+
+An example launch file for XML can be viewed [here](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/ros_gz_spawn_model.launch)
+An example launch file for Python can be viewed [here](https://github.com/gazebosim/ros_gz/blob/jazzy/ros_gz_sim/launch/ros_gz_spawn_model.launch.py)
+
+Example command for directly using these launch files from the terminal:
+```bash
+ros2 launch ros_gz_sim ros_gz_spawn_model.launch.py world:=empty file:=$(ros2 pkg prefix --share ros_gz_sim_demos)/models/vehicle/model.sdf entity_name:=my_vehicle x:=5.0 y:=5.0 z:=0.5 bridge_name:=ros_gz_bridge config_file:=<path_to_your_YAML_file>
+```
+
+More info about `ros_gz_bridge` can be viewed [here](ros2_integration).