On Oculus Quest, positional tracking is choppy

[kennardconsulting]

To reproduce,

First:

• Visit http://moonrider.xyz using the Oculus Browser on Quest
• Click to enter VR (glasses icon in bottom right corner)
• Bend your knees. Move your whole torso from left to right (i.e. like a 'strafing' action, not turning your head)
• Notice the edges of things like the 'Start' button and the grey star you are standing on (look down). They move in a choppy way.

Then Compare:

• Open Beat Saber demo (native app) and start tutorial
• Move to the corner of the black square you are standing on (with the white edge) and look down
• Repeat same left/right strafing movement Notice the white edges of the square. Notice movement is not choppy.

Notes

• Is not Moon Rider specific. Is easily seen on most AFrame demos, such as Anime-UI and Towers

I believe this is a bug in the Oculus Browser's positional tracking. Possibly the positional tracking is running at 60Hz while the headset is running at 72Hz?

​It has a significant impact on comfort for anything less than 2 metres away. It would be fantastic if the Supermedium Browser could fix this, given Supermedium will also be a native app.

[kennardconsulting]

Thanks for pinging this to the Oculus Browser team.

It may help them if you could confirm whether this also happens with the (upcoming) Supermedium Browser? Happy to side-load and test an APK if you have one?

[kennardconsulting]

Interestingly, this issue also happens on Firefox Reality on Quest (when sideloaded via APK). Something must be common in both stacks. But it doesn't happen on Exokit Native, so that must be using a different stack.

Will Supermedium use a different stack?

[kennardconsulting]

I can confirm this works fine in Exokit Native. You can try this for yourself by:

1. Downloading https://transfer.sh/ErXjp/app-debug.apk
2. adb install -r app-debug.apk
3. adb shell am start -n com.webmr.exokit/android.app.NativeActivity -e ARGS "'node --experimental-vm-modules /package -x webvr https://webvr.info/samples/03-vr-presentation.html'"

On Oculus Quest, the moving cube and the positional tracking are smooth, not choppy