I have doing hand tracking to place a ring on the index finger, but its pretty bad to show it to my client, I am using the indexLower joint to place and this is how it is:
I am not doing much here to the positions, the origin of the ring is in the center and still the tracking is really not good.
In the above image I posted, the models (spheres) are like 500 tris, my hand is centered and the lighting was adequate as well, but as I pulled my fingers apart, you can see the positions of the spheres was not at all tracking well with the joints of the bones.
And here I am just setting the spheres positions to the bone joint as is(coming from 8th wall) and not modifying anything related to position, scale or rot from my code.