RTABMAP data recorder problems

[rglaser4]

Hello,
I'm using RTABMAP with Ubuntu, ROS and the Kinect v2. I'm trying to do multi-session mapping using the data recorder. It records fine, but when I set the source to the recorded database and try to remap using the database. The odometry screen has a red background and shows the images and the 3DMap is all red. I would like to be able to use the data recorder with out running it in ROS, is this possible?

Also I'm using the multi session 1Hz config file but changing the location of the database source to my database. When I download the sample recorded databases and use them as the source when mapping everything works fine. Thanks for any help.



Thanks,
Ryan

[matlabbe]

Hi Ryan,

In the multi-session tutorial, the odometry was saved in the database. If you recorded data without odometry (just kinect's frames), then visual odometry should be computed, and in your case, the red screen means it is lost.

I suggest to create normal databases with odometry included, then do multi-session on these databases. Another note: if you do only hand-held mapping, you don't need ROS if you rebuild rtabmap from source with libfreenect2 support (so that standalone can be used to record data from kinectv2).

cheers,
Mathieu

[rglaser4]

Thanks for getting back to me so soon. I'm not planning on using ROS unless I had to for some reason. The original project started as autonomous drone but that was too much so we are settling for a wireless handheld scanner.

I guess what I'm not understanding is why my database doesn't include Odometry. Is there a setting or something that I'm missing or overlooking?

Thanks,
Ryan

[matlabbe]

Hi Ryan,

What are your steps used to record the data? From the standalone, using the data recorder tool doesn't record odometry. It is meant to record rgb/depth frames at camera frame rate, then odometry should be computed when replaying the database as source. I recommend to use data recorder tool from the main application (Tool->Data Recorder) as with the console app, you won't have any live feedback if odometry can be computed from the recorded data.

To record odometry in database, the easiest way is to just do a regular mapping session. When replaying that database, you will have to choice to reuse odometry saved in database or recompute it. The later option is not very recommended with that kind of database though, as the frame rate would be very low for odometry (in comparison to databases recorded from the data recorder tool).

On ROS, subscribe_odometry should be true for data_recorder.launch to record odometry in the resulting database.

cheers,
Mathieu