We are aware that our documentation is not sufficient in many categories, including ROS, we are improving our documentation for the next release which will be in mid November.
Hi Bruno, for your specific points it is often useful to check the ROS samples, check how the scenes are structured and the source code. You can find the source code under: /ros_samples for the integrated ROS samples - also callable by Isaac Examples → Communicating → ROS /python_samples/ros for native python ROS usage
Connect to existing ROS master
You should be able to do it by setting the ROS_IP and ROS_MASTER_URIenv variables. Let me know if you have issues with these.
Subscribe to ROS topic to move robot
Most our examples are doing exactly this. Start by checking the TurtleBot3 example which might be one of the simplest.
publish images from a robot‘s cam to a topic
There are several examples, maybe check the AprilTag or the ROS Stereo ones:
You can see that when you add a ROS_Camera to your stage, there are certain parameters that you can configured like the topics where you are publishing rgb, semantic, camera_info, etc