0 votes
by (120 points)

Hello,

if I activate multithreaded rendering in Unity 2020.3.34f1 using URP 10.9.0 with XR SDK 2.0.3 - 2.0.5 the gamplay stutters in 72HZ mode -> if multithreaded rendering is deactivated it is smooth, but the renderthread makes it cpu bound and drop frames when there are more then 150 drawcalls.
Is it possible to have a workaround for using multithreading with 72HZ without stuttering?

It is for some reason runnning smooth with multithreading in 90HZ mode.
Or is it possible to for the Neo 3 to force 90 hz for the game from script?
From my tests it only works in 90HZ when experimental 120HZ mode is activated -> else it defaults to limiting it at 72 HZ.

In the documentation there is a line about multthreaded rendering that links to this site: https://docs.unity3d.com/ScriptReference/SystemInfo-graphicsMultiThreaded.html
which seems to me should be part of the sdk handeling the rendering.

2 Answers

0 votes
by (3.3k points)

Here is the doc about set Screen Refresh Rate. And im curious why your app can run smooth in 90hz but cannot in 72hz, perhaps you can do some optimization in your scene.
https://developer.pico-interactive.com/docs/en/12058/unity-xr-sdk-ScreenRefreshRate/

by (120 points)

I know this setting and already use it, but if the user is not selecting 120HZ mode in his device settings -> it will still run at 72HZ, at least from Metrics tool info and unity analysis.
So it doesn't help with the problem. I was wondering if we can force the users device display refresh rate to be 90 HZ. On the Quest 2 the default is 90HZ and on the Neo 3 the default still seems to be 72HZ.

The game is very well optimzed and running perfectly smooth with 90hz on the Quest 2. It also runs fine with multithreaded rendering on other VR standalone platforms.

The problem seems to be that multithreading is not working properly. I have to deactivate it to not have jitter -> from analysis in unity this seems to be a problem with multithreaded rendering taking too long and delaying the frame render.

0 votes
by (27.7k points)

Deer developer,
Thanks for your responding. For your fps question, if you want app run 90hz in our headset, you need open 120hz mode in Setting and set Screen Refresh Rate at 90hz in Unity. For your multithreaded question, we already fed back the problem to the development department. If there is any progress, we will comment as soon as possible.
Thank you

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