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Trackable lost, default to using last position as world origin

February 14, 2012 - 11:59pm #1

How do you get trackable lost to not have the object just sort of "drift away" but instead take the last trackable position as the new origin position?

Trackable lost, default to using last position as world origin

November 19, 2012 - 1:20pm #8

Can anyone recommend libraries a/o plugins for working w/ this data in Unity?

The approaches that I've seen, which rely on camera orientation, typically require a calibration phase in which you register the device in a known orientation. Though I've seen other examples that use relative orientation.

Trackable lost, default to using last position as world origin

November 17, 2012 - 12:00am #7

I'm very interested in this (using gyro data to keep the model in place when the target is lost) - it's exactly what I am trying to accomplish. Did anyone have any luck implementing this?

Stefann's approach looks like a good one to me. Can someone give me a tip on how to rotate the camera?

Re: Trackable lost, default to using last position as world orig

February 17, 2012 - 2:14am #6

hi ina,
this is a very interesting idea and in fact i started working on exactly that a few days ago. however it turns out that it's not that easy because the last frame before a trackable is lost often doesn't give you very good position information. therefore i would recommend to store the last few transform combinations in an array and use an earlier one as reference.
then you need to align the sensor values with the rotation of your camera and from there on it's like taking just rotating the camera from the gyro/compass/accelerometer values.
so, to answer your question, yes, it's possible but definitely tricky ;-) hope this helps a bit...
best,
stefan

Re: Trackable lost, default to using last position as world orig

February 16, 2012 - 3:49pm #5

So, instead of using multiple markers triangulation...

Single marker - this determines the "absolute origin" - and gyroscope/accelerometer keep that "in place" even when the marker is out of range of the camera..

What do you think?

Re: Trackable lost, default to using last position as world orig

February 16, 2012 - 3:45pm #4

Hmm, rather than image tracking, what about a way to combine gyro/accelerometer to determine the "position" of where the marker was before it left the camera's view?

Re: Trackable lost, default to using last position as world orig

February 15, 2012 - 8:00pm #3

You might be interested in Elecman's work on a Unified Coordinate System for trackables in Unity:

http://ar.qualcomm.at/node/2001030

- Kim

Re: Trackable lost, default to using last position as world orig

February 15, 2012 - 12:40am #2

It seems like the Sony SmartAR stuff can be emulated via QCAR by having the origin be the last marker position

http://www.sony.net/SonyInfo/News/Press/201105/11-058E/index.html

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