update urdf_config.rviz

[harderthan]

There are beginners who follow tutorials get confused because of two reason below.

• Initial Fixed Frame value of Rviz is base_link, not odom or map.
  • Initial value of Durability Policy of rviz_default_plugins is Volatile, not Transient Local.

These can be confusing whether the /map topic is published or not during this step

You can see that the map message is visualized on the Rviz without any special action, if apply this mr.

There is the case on ROS ANSWERS

[SteveMacenski]

https://navigation.ros.org/setup_guides/urdf/setup_urdf.html the first tutorial is in setting up the TF tree, so this cannot be in odom frame because that would not exist yet for users to visualize any of the data.

Adding in the map visualization by default would be nice in future steps, but the same issue occurs for the initial steps - the topic doesn't exist yet. If it is checked "off" and no errors appear, I would be OK adding that so its easily togglable, but the frame has to keep as base_link. Can you confirm that there's no errors when this is toggled off and update the PR to have it unchecked by default?

[harderthan]

Thanks for the advice.
(It seems that someone like me doesn't go through the guide documents one by one in order.)

• If set to base_link, the map topic is not visualized regardless of the /map topic toggle. Users have to set to 'odom' or 'map' on Fixed frame at least once.
• If the toggle is checked "off", then there are no errors.

In my opinion, all steps of First-Time Robot Setup Guide uses the default Rviz config, that's why this misunderstanding seems to arise.

When you check the map topic visualization through Rviz, you need to check that "Fixed Frame" is "map" or "odom".

I think it is more desirable to just add the above message on Launching slam_toolbox of "Setting Up Sensors" . How about your opinion?

[SteveMacenski]

If set to base_link, the map topic is not visualized regardless of the /map topic toggle. Users have to set to 'odom' or 'map' on Fixed frame at least once. I think it is more desirable to just add the above message on Launching slam_toolbox of "Setting Up Sensors" .

Agreed, it would be good to add to the tutorial at that step to change the view to map. We can add your map display object though here if you uncheck it by default and update your PR. That should resolve the concern fully, no?

[harderthan]

I update this mr with false for uncheck.

    - Class: rviz_default_plugins/Map
      Enabled: **false**