iOS: odometry reset to origin after recording over 2000 nodes in Data recorder mode

[matlabbe]

Not clear what is happening, I saw some long scans (recorded in Data Recorder mode) where near the end it seems there are some lags (>5 sec) that are causing "lost" events, making rtabmap resetting to origin the odometry. Based on the data of the database, it doesn't look like someone did a reset manually, and it looks like it was during fast rotation in textureless areas. I couldn't reproduce that bug though even by hiding the camera, there could be something happening with ARKit failing for some reasons after 2000 nodes recorded (RAM issue?). Here is where ARKit can potentially return lost, then a new map (odometry is reset to origin) is triggered:

rtabmap/app/ios/RTABMapApp/RTABMap.swift

Lines 343 to 354 in 51cfc37

	var lost = false
	switch frame.camera.trackingState {
	case .normal:
	lost = false
	case .limited(.excessiveMotion):
	lost = false
	case .limited(.insufficientFeatures):
	lost = false
	default:
	lost = true
	}
	// Notify lost with pose=null

[matlabbe]

Suggestion: Try to reproduce the issue, and when a new session is about to be created, we should show a warning to the user so that he can know that he/she be backtracking a little to make sure the new session overlap the previous one.