Using namespace in the launch file doesn't work

[ShayonMitra]

I am trying to extend the environment to multiple agents. In order to do so, I am adding namespaces in the launch file. The spawn process happens normally and is reflected in the terminal. But a black rviz screen shows up and these error messages appear.

Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/robot_description'
Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/camera_description'

Initialization complete.

Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/lidar_description'
Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/camera_description'
Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/robot_description'
[ INFO] [1728381882.894049536]: Finished loading Gazebo ROS API Plugin.
Traceback (most recent call last):
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 239, in
exit_code = sm.run()
File "/opt/ros/noetic/lib/gazebo_ros/spawn_model", line 132, in run
model_xml = rospy.get_param(self.args.param)
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/client.py", line 467, in get_param
return _param_server[param_name] #MasterProxy does all the magic for us
File "/opt/ros/noetic/lib/python3/dist-packages/rospy/msproxy.py", line 123, in getitem
raise KeyError(key)
KeyError: '/lidar_description'
[ INFO] [1728381882.915256189]: waitForService: Service [/bot1/gazebo/set_physics_properties] has not been advertised, waiting...
[bot1/spawn_robot-9] process has died [pid 50159, exit code 1, cmd /opt/ros/noetic/lib/gazebo_ros/spawn_model -urdf -param /robot_description -model robot __name:=spawn_robot __log:=/home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_robot-9.log].
log file: /home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_robot-9*.log
[bot1/spawn_camera-7] process has died [pid 50151, exit code 1, cmd /opt/ros/noetic/lib/gazebo_ros/spawn_model -urdf -param /camera_description -model camera __name:=spawn_camera __log:=/home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_camera-7.log].
log file: /home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_camera-7*.log
[bot1/spawn_lidar-8] process has died [pid 50157, exit code 1, cmd /opt/ros/noetic/lib/gazebo_ros/spawn_model -urdf -param /lidar_description -model lidar __name:=spawn_lidar __log:=/home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_lidar-8.log].
log file: /home/shayonmitra/.ros/log/bad5b884-855c-11ef-a344-0ff38bd98261/bot1-spawn_lidar-8*.log

Any fixes?