Is user_data used in mapping or loop closure detection?

[MWrock]

I was looking through the code and examples, but it wasn't apparent if the user_data_async (or user_data) topics are actually used in loop closure detection and mapping or just displayed ad visualisations in RVIZ. Hopefully someone can shed some light on the situation

[matlabbe]

Hi,

user_data is not used for loop closure detection and mapping. It is used to save some custom data to database. The user data is republished with the whole map data. An example of usage can be found here: http://wiki.ros.org/rtabmap_ros/Tutorials/WifiSignalStrengthMappingUserDataUsage

cheers,
Mathieu