we are currently developing a Hololens Application for a fair using Vuforia marker tracking. When starting the application first time, we detect the marker and everything works fine. The problem is, after a user take off the hololens and lays it down to its desired place on the booth and the next user is taking it on after a while, the position of the scene is completly wrong, like either way too low, 3 meters shifted to the left or flying around somewhere on the booth. We need to manually rescan the marker then every time this happens.
Is there a way to detect a wrongly positioned scene or if a user took on the hololens and then force the user to rescan the marker or avoid this problem at all? We know it might be a problem with the way we lay down the hololenses on the booth since they are haning on a hook next to the target scene (facing towards the floor).
Its very annoying to every time check the position of the scene before handing a hololens to a visitor.
P.S. the hololenses are turned on all the time and are always connected to a USB cable for charging.