Transform of any tracked devices appear delayed by a frame

[Hayden-Fluff]

Describe the bug

The transform of slots driven by a tracked device using TrackedDevicePositioner is seemingly always delayed by a frame, causing very jarring disconnects, any elements if your avatar's head that can be seen in first person to be off and due to HMD tracking jitter, seemingly vibrating constantly, and when moving fast, elements of the avatar clipping into the first person view (such as any facial accessories, hair, or the back of the face)

Relevant issues

None to be found

To Reproduce

• Equip any avatar (Full IK seems to be the best, though this has been very clearly shown in head and hands as well) -- Move head around at a relatively fast pace -- Notice that the avatar's head is delayed from your view (The effect is much more noticeable with lower framerates)
• Open a VR Overlay which has a wrist menu -- Move hand wrist menu is on -- compare the delay of the position of the tracked object in Neos compared to the overlay position (Once again more noticeable with lower framerates)

Expected behavior

As seen in many other VR applications, I'd expect that any tracked device transform would be 1:1

Screenshots / Video

Will post some later once I have the energy to record them

Bug information (please complete the following information):

• How often does it happen: A very large majority of the time
• Does the bug persist after restarting Neos? Yes
• Neos Version: 2021.5.23.985
• Neos Platform: Experienced on Windows
• Link to reproduction World/Item: N/A
• Regression: I think there was a point at which this didn't happen, though that was very long ago and don't even know where to start looking for that.

Additional context

I have had a case once where the head of an avatar was completely 1:1 to the view, however I have no idea what I did to trigger it, and it did not persist after reloading the avatar.

Reporters:

Hayden#3180

[Frooxius]

What makes you say that it's any tracked device? The system is updating the poses before the transforms update, so it's very unlikely that this is really the case.

The issue with avatar clipping into the view has a different cause that's unrelated to the tracked devices and is planned to be fixed.

[Hayden-Fluff]

Considering I see this on anything that is tracked (head, hands, trackers) and is also visible on head and hand avatars, I'd think that it'd be unrelated to the avatar system.

[Frooxius]

There are other possible causes as well though, notably with head some late view update just prior to rendering. In case of the overlay the difference in the framerate will make this more obvious, since the overlay can be updating at much faster rate and get more recent values, but it doesn't necessarily mean the data is delayed by a frame.