You're welcome

Ok, thanks a lot, we will try that :-)

Regards,

    Vincent.

OK,

This is what I would probably try out in this case:

when you want to "reset" (so to speak) the tracking, do the following (in this order):

1. stop the ImageTracker (and then reset Ext Tracking in case you also use it)
2. trigger an Autofocus event, using the FOCUS_MODE_TRIGGER_AUTO (see VuforiaSamples for an example of it)
   • see also: https://developer.vuforia.com/resources/dev-guide/continuous-autofocus-and-other-focus-modes 
   • this will enforce your device camera to quickly readjust the focus to an optimal way
   • the user will also get a sort of "visual" feedback, because the camera image blurriness will visibly change for about half a second or so
3. restart the ImageTracker

I think this is probably the best option you have to get as close as possible to the scenario you describe.

We already do. For ET, it's good about the procedure to reset. 

But for the tracker stop/start, it does not reset anything, just stop a frame, detecting again with the same wrong result. We could make it more obvious for user, but our main problem it to really to force a new detection when not good.

Thanks.

Instead of moving the camera awayn we are trying to make something automatic that could detect and reset the capture, something more understandable for non-technical people that could use the product.

Then you could simply stop the Tracker and restart it (e.g. restart after waiting 0.5 second, to make it more obvious to the user)

(and if you use Extended Tracking, also reset ET in between stopping and starting.)

Is the target printed on a flat surface ?

Yes, default paper, A4 format, black and white.

is there any glossiness / reflective surface  on the printed target ? 

The default paper is not reflective so I'm pretty sure this is not an issue.

Instead of moving the camera awayn we are trying to make something automatic that could detect and reset the capture, something more understandable for non-technical people that could use the product.

Thanks !

If you are not using Extended Tracking, then you would not even need to stop / restart the Tracker; you could just move the camera away from the target, so that you loose tracking, and then back to the target;

if the Pose is still inaccurate, then it's not a matter of "resetiing" tha tracker, but it's likely an issue with the Target itself (or the angle between the camera and the target, as you suggest).

Other things you may want to check:

Is the target printed on a flat surface ?

is there any glossiness / reflective surface  on the printed target ? 

Stopping the Tracker, Resetting ET and restarting the Tracker is the correct way for this.

Even when the tracking is not extended ?

Our targetis a five star ratin, ligthning is good, the only bad point is we generally start not completely front to the Target but in a 45° angle, and more after that during traking (tracker on the floor) but sometimes, even starting quite front to the target tracking is bad...

Thanks whatever.

Regards,

    Vincent.

Stopping the Tracker, Resetting ET and restarting the Tracker is the correct way for this.

Could it be that the pose keeps being wrong (even after reset) simply because the Target has a low star rating, it is too far or maybe because you are working in low lighting conditions ?

Otherwise, a video showing the issue would help understand better the problem you see.

Hi, Sorry to insist but the "default" tracking make a important number of bad tracking (3D model upside down, or with a strange rotation) and I would like to know how I can reset/force restart in this case.

Thanks a lot !

Regards,

   Vincent.

Hi !

Please, no way to restart completely the tracking ?

Thanks !