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Image tracking jitter

January 8, 2021 - 2:22am #1


I have been experiencing an issue where the 3D model will have a jittering effect (flicks through rotation angles and position coordinates) when the device camera is facing directly onto the image to track.

Due to the size of the model compared to the real world image to follow, I am needing extended tracking enabled but have read that is may be the cause of the jittering.

I have created a damping system to smooth out the jitter to moderate success, as in it is working but the jitter is still present.  This was done by unparenting the 3D model from the Image Target object and writing a script that would copy the position and rotation of the Image Target in a Vector3.SmoothDamp and Quaternion.Slerp.

I have tried the Render Over Native UI toggle in the Resolution and Presentation options but that didn't show any changes.

I should also mention I am building this for both Android and iOS platforms.

Unity: 2019.4.15f1

Vuforia: 8.5.9

Is there any way to remove the jitter to have the model completely stable?

Thank you for any help with this matter.

Image tracking jitter

January 19, 2021 - 5:34am #2


Pose jitter exists for all 2D planar targets. The magnitude of the jitter (hardly noticeable to very noticeable) can be impacted by a few factors:

1.Always print the image that was uploaded to the portal to the exact same aspect ratio. Any stretching or altering of the image may cause tracking pose jitter. Some printers default to "stretch to fit", which can change the aspect ratio.

2.Check the size values you are using when uploading Targets to the Vuforia Target Manager. Note there is specific language used in the dialogue box that says Vuforia uses meters as the default unit scale. Incorrect target sizes could affect either our detection/tracking algorithm

3.Image Targets must be flat when in the camera's field of view

4.Not enough lighting upon, and/or spectral reflections occluding the Image Target

5.The entire target image is not in the camera's field of view. As Image Targets extract feature points from the target in real time (on a frame-by-frame basis), the more feature points the better the quality of the tracking experience. In most cases, this can be improved by enabling the Device Tracker (aka Extended Tracking): Unity Editor->Window->Vuforia Configuration->Device Tracker->Track Device Pose (box checked).

For additional tips for optimizing 2D planar targets, please see the following guide: https://library.stage.vuforia.com/articles/Solution/Optimizing-Target-Detection-and-Tracking-Stability

Thank you.

Vuforia Engine Support

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