Issue with use_sim_time.

[rafal-gorecki]

Hello, I notice when I spawn robot_state_publisher and robot_state_pub_node with SetParameter(name="use_sim_time", value="True"). Nothing is publish on /joint_states topic. Any suggestion why is that?

[sloretz]

When use_sim_time is True anything that tries to access time will use the time published on the /clock topic. I would expect joint_state_publisher to not publish anything when nothing is publishing the time on the /clock topic.

Is something publishing time on that topic? Usually the thing publishing time is a simulator like gazebo, or a playback tool like rosbag.