Multisession mapping - transform between maps

[quizzy5889]

Hi Matlabbe,
I'm using RTabMap Desktop to reconstruct indoor environments.
First of all really thank you for your work, it's really amazing.

To accomplish my work, which is not only 3D reconstruction, I use to save the final sqlite DB to extract the information needed to trigger my postprocessing pipelines. Sometimes it happens that the DB contains multisession mapping info.

The question is: I don't find in any place in the DB the transform between map0, map1, map2 and so on...
Is it possibile to extract this info directly from the DB? Could you please help me?

Thanks a lot
Andrea

[matlabbe]

Hi Andrea,

There is no explicit transform between the sessions, actually there could more than one constraints between two sessions. This is when we optimize all the constraints that we could recover the transform between first node of map0 and first node of map1. Assuming that all sessions are merged together in the database, a way to get the optimized graph is the one saved here in the database. You can then estimate yourself the transforms between the sessions.

cheers,
Mathieu