This is when directly accessing the OpenXR hand tracking EXT in StereoKit (not Unity).
Quest 2 thumbs are about 90 degrees off from what I expect to see from the OpenXR spec! It appears as though the thumb is using +Y to face up from the back of the hand, rather than the top of the thumb. This is inconsistent from the spec, as well as from other runtimes.
The OpenXR spec defines +Y like this: "The up (+Y) direction is pointing out of the back of and perpendicular to the corresponding finger nail at the fully opened hand pose."
A little hard to understand without a visible hand here, but you can see +Y (green) coming out the side of the thumb here. This is running on Quest 2.
Same scene running on a HoloLens 2, you can see here +Y (green) coming out the top of the thumb, not the side.
Solved! Go to Solution.