Supports Carla 0.9.13?

[Chuck1989niu]

I wanted to test Carla0.9.13 with ROS2 and ROS bridge. The CARLA part is running correctly.Start the ROS bridge properly.(ros2 launch carla_ros_bridge carla_ros_bridge.launch.py), however when I try to launch Spawn objects, I get an error that one of the parameters is None.

My environment:

Ros 2 Foxy
Carla0.9.13 on brach master
Latest ROS bridge

Execution command :
The CARLA part:
~$ cd carla
~$ make launch (play)

The ROS2 part:
~$ cd carla-ros-bridge
~$ source ./install/setup.bash
~$ ros2 launch carla_ros_bridge carla_ros_bridge.launch.py timeout:=30
In another terminal
~$ ros2 launch carla_spawn_objects carla_spawn_objects.launch.py

The full exception:

[INFO] [launch]: All log files can be found below /home/chuck/.ros/log/2022-03-08-09-55-46-690946-chuck01-10518
[INFO] [launch]: Default logging verbosity is set to INFO
Task exception was never retrieved
future: <Task finished name='Task-2' coro=<LaunchService._process_one_event() done, defined at /opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py:226> exception=TypeError("Allowed value types are bytes, bool, int, float, str, Sequence[bool], Sequence[int], Sequence[float], Sequence[str]. Got <class 'NoneType'>.If the parameter is meant to be a string, try wrapping it in launch_ros.parameter_descriptions.ParameterValue(value, value_type=str)")>
Traceback (most recent call last):
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 228, in _process_one_event
await self.__process_event(next_event)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/launch_service.py", line 248, in __process_event
visit_all_entities_and_collect_futures(entity, self.__context))
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 45, in visit_all_entities_and_collect_futures
futures_to_return += visit_all_entities_and_collect_futures(sub_entity, context)
[Previous line repeated 1 more time]
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/utilities/visit_all_entities_and_collect_futures_impl.py", line 38, in visit_all_entities_and_collect_futures
sub_entities = entity.visit(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch/action.py", line 108, in visit
return self.execute(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/actions/node.py", line 444, in execute
self._perform_substitutions(context)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/actions/node.py", line 399, in _perform_substitutions
evaluated_parameters = evaluate_parameters(context, self.__parameters)
File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/utilities/evaluate_parameters.py", line 160, in evaluate_parameters
output_params.append(evaluate_parameter_dict(context, param))
File "/opt/ros/foxy/lib/python3.8/site-packages/launch_ros/utilities/evaluate_parameters.py", line 95, in evaluate_parameter_dict
raise TypeError(
TypeError: Allowed value types are bytes, bool, int, float, str, Sequence[bool], Sequence[int], Sequence[float], Sequence[str]. Got <class 'NoneType'>.If the parameter is meant to be a string, try wrapping it in launch_ros.parameter_descriptions.ParameterValue(value, value_type=str)

How can this error be resolved?

[alexkutsan]

Same question from me :-)
Not able to use 9.1.12 because of issue carla-simulator/carla#3599
But 9.1.13 not compatible with ROS bridge

[FelipeGdM]

I had the same problem when trying to run ros-brigde with Carla 0.9.13. Running it with a modified version of launch_ros (ros2/launch_ros#320) it was possible to discover that the problem is the evaluation of the parameter spawn_point_ego_vehicle.

I believe that if you pass any string for the parameter spawn_point_ego_vehicle in the command line, the error shouldn't occur.

ros2 launch carla_ros_bridge carla_ros_bridge_with_example_ego_vehicle.launch.py spawn_point_ego_vehicle:=spawn_point

If you pass an invalid string, the message should be

[carla_spawn_objects-4] [WARN] [1656355794.696531425] [carla_spawn_objects]: Invalid spawnpoint 'spawn_point'
[carla_spawn_objects-4] [WARN] [1656355794.697031216] [carla_spawn_objects]: ego_vehicle: Could not use 
spawn point from parameters, the spawn point from config file will be used.

And then ros bridge runs normally

[mostafa23988]

Just change the Carla version written inside the file "carla-ros-bridge/install/carla_ros_bridge/lib/python3.8/site-packages/carla_ros_bridge/CARLA_VERSION" from "0.9.12" to "0.9.13"

[berndgassmann]

Hi,
I found a different solution for the problem with the spawn_point by explicitly converting it to string after launch.substitution. See one of the launch files here. Even if I am working on 0.9.11 branch, I believe this solution should also work independent from the CARLA version (as it's related rather to the ROS2 version used).

[andrejpadilha2]

Worked for me @FelipeGdM, thank you/muito obrigado!