how to get self-position in localization mode

[masaki12-s]

I am using RTABMAP on Windows 10 for localization.
I want to get the coordinates within a room.
After generating a 3D map in "Mapping" mode, I would like to get the self-position in "Localization" mode.
Where is the estimated self-position stored in "Localization" mode?

[matlabbe]

What do you mean by "how to get"? programmatically? In localization mode, you should see the pose of the virtual camera frame in 3D map view matching where it is localized. In code, the localized pose is determined by latest odometry pose and the map correction.

Here is where the camera frame of 2d view is updated on odometry event:

rtabmap/guilib/src/MainWindow.cpp

Line 1588 in 2acd8f8

_cloudViewer->updateCameraTargetPosition(_odometryCorrection*odom.pose());

The _odometryCorrection is updated when receiving a new rtabmap event:

rtabmap/guilib/src/MainWindow.cpp

Line 2394 in 2acd8f8

_odometryCorrection = stat.mapCorrection();

[masaki12-s]

I would like to get the coordinates on the windows GUI.
" Mapping" mode is mapping with self location and the trajectory is drawn as a blue line. The coordinates can be obtained from "poses.txt".
however, in "localization" mode, the trajectory is drawn as a pink line, which disappears over time. Also, it cannot be retrieved from "poses.txt". I would like to get the coordinates of this pink line.

[takanotume24]

@matlabbe Hello, thank you for your detailed answer. I am a participant in the same project as masaki12-s. Thank you very much for your detailed answer.

What we wanted to know is how to get the self-position in localized mode programmatically, as you said, it would be better to get the pose of the virtual camera frame, we are using RTAB-Map for the purpose of getting the self-position after generating the 3D map. I will try to get it from the C++ code you taught me. Thank you for showing us the relevant code.

Also, as an addendum to masaki12-s question, is there a mode implemented in the Windows version of the GUI software to get the pose of the virtual camera frame with timestamp?

[matlabbe]

The pose is published by odometry event. An example of handling the odometry pose and transform it in current map frame can be found here:

rtabmap/guilib/src/MainWindow.cpp

Line 1590 in 0f221ba

_cloudViewer->updateCameraTargetPosition(_odometryCorrection*odom.pose());

For simpler example, a similar approach is done in the c++ example:

rtabmap/examples/RGBDMapping/MapBuilder.h

Line 156 in 0f221ba

cloudViewer_->updateCameraTargetPosition(odometryCorrection_*odom.pose());