How to change a urdf model property using a roscpp node
Hi, I am trying to change the color of a part in a URDF model that is visualized in RVIZZ whenever a contact occurs. I have already written a roscpp node that detects the contact at the previously mentioned part but I want this node to change the color property of this part in the URDF file in live mode. I tried using a ros server parameter for the color but I didn't know how access its value in the URDF file. It would be really appreciated if someone can tell me how to properly do this. Thanks!
Asked by aaa on 2021-10-15 19:12:15 UTC
Comments
Quick comment: it's certainly possible to load the
robot_descriptionparameter, parse it using something like urdfdom, change a property of some entity.However, what is less than trivial is getting consumers of
robot_descriptionto reload that parameter. Updating parameter values at runtime is not a pattern that's often used: parameters are only read once during initialisation. For parameters changing at runtime you'd use dynamic_reconfigure, but that's not often (at all?) used forrobot_description.If you can control your consumers of
robot_description, you could force them to reload that parameter, but that's non-trivial again.I would suggest to take a look at how MoveIt implements this, using its special MoveIt RViz plugin. You'll see it doesn't change the URDF, but only the way it renders it inside RViz.
Asked by gvdhoorn on 2021-10-16 03:16:13 UTC
I agree with @gvdhoorn that changing the urdf is not a good way to do this. In addition to the plugin he pointed you to, take a look a the rviz Marker feature. It may not be as pretty, but it'll take much less code to implement.
Asked by Mike Scheutzow on 2021-10-16 08:06:22 UTC