I am trying to display an object that is located in front of the camera. I noticed that the farther the object is away from the origin (the AR Camera), the more jittery the object becomes.
I was able to reproduce this in the Unity sample for the wood chips with gold teapot. Move the teapot in the z direction a pretty good amount. You will notice that the teapot is slight jitter and is very noticeable. Notice the scale of the Image Target (and hence the teapot is huge, like 32 meters if 1 meter = 1 unit).
I also noticed that the objects are "more" jittery when the scale is changed to a more realistic dimension. In this case change the dimensions of the Image target keeping the same aspect ratio -> (X,Y,Z) = (1.428572, 1.214286, 1). Now move just the teapot to Z = 15 and a little off center with Y=4. Notice how the object (the teapot) is *super* jittery.
Changing the scale of the objects to something big really screws up the physics.
How do I fix this ... it's kind of a show stopper for me.