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Override default marker behaviour

June 22, 2014 - 6:44am #1

Hi all,

I cannot seem to figure out how to override the default marker behaviour.

What I want is this:

- on losing the marker -> interpolate camera to a position close to the object being tracked

- on finding the marker -> interpolate camera back to the tracked position.

So basically I would like to find out what the transformation matrix of the camera should be when a marker is detected, without updating the camera itself.




Override default marker behaviour

June 27, 2014 - 12:53am #3

Hi Pierre,

no I am using a framemarker at the moment. Although using the image marker with extended tracking is also an option, with both marker types it is possible to lose track of the marker at some point.

My question is about what I would like to do when that happens.

What I have now:

on losing marker track: interpolate camera smoothly to an upclose view of the model that should be on the marker

What I would like to add is:

on regaining marker track: interpolate camera smoothly back to accurately tracking the object on the marker.


In the end I used onTrackersUpdated() (or something similar) to do what I want, then it turned out to be a crappy solution game play wise, so now I ditched the interpolation all together and just show some static special effects when the marker is lost :).




Override default marker behaviour

June 25, 2014 - 3:12pm #2

Hi Hans,

First a quick question: what you call "marker" is an image targets right? Asking you because we also have a feature called "frame markers" (https://developer.vuforia.com/resources/sample-apps/frame-markers-sample-app)


If I read you correctly, you want to have some kind of tracking if you lose the target. If that's the case, we have a feature SDK which handles this use case: Extended Tracking


You can see it in action in the "Vuforia Features Sample Package" : if you enable extended tracking from the menu, you'll see that the tracking continue even after the target is no more in sight.


Hope that helps.



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