Hi

Lets just keep it plain and simple and use the preinstalled Vuforia templates that came with the package

This shows you what I mean: >> https://imgur.com/cplp9FF

In Unity I have used Vuforia Images: Astronaught image target. I didn't upload anything to the Vuforia Target Manager. I am using what came preinstalled with Vuforia package.

The image target size was auto set to 0.12cm, as if I am correct in understanding, 12cm height of image target is converted to 0.12 in Unity? Anyway, I did not change this setting, it auto chose itself when I selected the Astronaught.

Then you can see the image target that I printed, which is the information/size etc that Vuforia outlines. I printed this and cut it out and stuck it to some cardboard. The scale of my Kidneys in Unity is also 0.12 (but changeable)

So far nothing should be wrong, am I correct?

I build to my phone and this is the result. https://imgur.com/BlxOLXg 

I have done everything right.

Even uploading a 1024x512 Vuforia Stones  that I downloaded online doesnt do a splendid job.

Why does the size value of the target matter as its changeable in Unity...

And when you say the Entire Image is not in the camera's field of view, is that in Unity or the actual phone camera? 

Hello,

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).

In your video I noticed that when the entire stones target is in the camera's field of view, tracking looked stable. However, when you moved closer to view the augmentation (and only a fraction of the original target can be seen) it became more jittery.

Thanks,

Vuforia Engine Support