I am developing an app for cardboard with Android 7.0 nougat, with a Samsung S6.
It's an AR/VR mixed reality game obtained from modifying the AR/VR vuforia sample.
In AR mode, i set the max number of Image targets to 2 - and in fact It is able to render objects in both targets at the same time.
My targets are of different sizes, one is printed on a A4 paper (21x310cm) and the other is 10x10cm.
However, if one target is lost (e.g. goes outside the FOV) vuforia seems to have a very hard time to detect It again:
If the other target is lost aswell, then the first one is immediatly rendered.
At the moment the bigger target lies on the desk, while the smaller one is on the hand. Often the tracking on the hand is lost, and the only reliable way I found to detect It again is to cover the whole camera view with the hand, and then slowly return in the right position, but It dramatically hinders the playability.
My targets are both rated 5 stars (I'm using the stones and wood chips images from vuforia). The bigger target also has extended tracking activated. Camera mode is set ti fast, but had similar issues with default settings.
It seems like It could be a performance issue , or maybe because of the focus of the camera (althought i did set focus mode to CONTINUOUS_AUTO).
Do you have any suggestions to improve the reliability of the detection with multiple targets? I've read the best practices to have good imagetargets, but the problem doesn't seem to be in the targets (I've even tried different types and sizes, from multibox to smaller imagetargets and bigger ones)
Note: once both targets are detected, the tracking works just fine - It rarely loses track of them unless one goes outside the FOV.
Thank you for the help.