ROS2 Ego Vehicle Example crashes.

[amansrf]

When trying to install the ros-bridge for ros2 foxy following this guide, the ego vehicle ros-bridge example crashes ros2 launch carla_ros_bridge carla_ros_bridge_with_example_ego_vehicle.launch.py

I get the following error on terminal:

System Specs: OS: Ubuntu 20.04 ROS: ROS2-Foxy Carla & Rosbridge Version: 0.9.12

[Jia-Wei-Wang]

System Specs: OS: Ubuntu 20.04 ROS: Release -foxy-20220208 Carla Simulator&ROS bridge: tags/0.9.11

After installing <Release -foxy-20220208>, I encountered the same errors when I want to launch carla_spawn_objects. Main program carla_ros_bridge and carla_manual_control can be launched successfully with parsing input arguments, e.g. town:="Town03" fixed_delta_seconds:=0.05.

My temporary solution is to run python script carla_spawn_objects.py and set the input argument to hard-codedobjects_definition_file = '/path/to/cfg.json' and It works.

[amansrf]

I tried your suggestion by running the following command after starting the carla_ros_bridge , however I still received the same error.

Exact steps I took:

1. Started the Carla Server ( ./CarlaUE4.sh)
2. sourced carla-ros-bridge workspace and then ran ros2 launch carla_ros_bridge carla_ros_bridge.launch.py succesfully
3. In a new terminal, I tried to launch the carla_spawn_objects launchfile using the following: ros2 launch install/carla_spawn_objects/share/carla_spawn_objects/carla_spawn_objects.launch.py objects_definition_file:=install/carla_spawn_objects/share/carla_spawn_objects/config/objects.json

I get a similar error as before. Did I choose the wrong launchfile or wrong object file?

[Jia-Wei-Wang]

I use python(3.8.10) to execute carla_spawn_objects.py. I would suggest that you re-use the class CarlaSpawnObjects() to write your own launch.

In terminal python3 your_own_script.py instead of ros2 launch ... ...

I don't think this is a proper way to spawn sensors as I said. It is just a temporary method.

[wuxiaohua1011]

Short answer: Simply provide name(i think the carla team intended the spawn_point_ego_vehicle_value to be filled with name?) for ego vehicle ros2 launch carla_ros_bridge carla_ros_bridge_with_example_ego_vehicle.launch.py spawn_point_ego_vehicle:="spawn_point_hero0"

and then you can use RVIZ to see the camera data streams and stuff.

Long answer: So tracing back, I see that the carla_ros_bridge_with_example_ego_vehicle.launch.py calls carla_spawn_objects.launch.py, which the latter requires this field called spawn_point_ego_vehicle.

Recommendation to CARLA team: maybe provide an actual default value instea of empty string for spawn_point_ego_vehicle field?