Windows Mixed Reality HMD shutter lag after 5.2 Update

Hi,
we are testing VR template project with the current UE 5.2.1 and have found that while using HP Rewerb G2 headset with Windows Mixed Reality as runtime there is very noticable lag in the HMD view even when fps is maintained at 90 and the HMD tracing is jittery jumping back and forth.
Going back to 5.1.1 solves this.

This seems to have beed discussed already here but it doesnt provide a solution, rather a workaround using SteamVR as XR Runtime and the thread has beed closed without bug report:

Specs:

Windous 11 Pro
AMD Ryzen 9 5900X
RTX 3060
32 GB DDR4 Ram

UE ver: 5.2.1
Project: VR Template (No changes to project settings or scene)

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I am experimenting the same issue. Tested if its still present in the new 5.3P in default Virtual Reality template project and its still there. Falling back to 5.1 or using SteamVR instead of WMR seem to be the only workarounds for now but that is not optimal as Steam VR has its own issues with WMR headsets.

Maybe @VictorLerp cold help.

It would seem that itā€™s an issue w. the runtime, as we havenā€™t received any reports of it happening w. SteamVR or Oculus w. 5.2+. I unfortunately donā€™t have anything useful to share, but Iā€™ll update this thread if something is discovered.

Hello! Have you found any solution to this? Iā€™m experiencing the same issues with my HP reverb 2 and Unreal engine editor and canā€™t figure out how to solve this. Everything else runs smooth except the unreal engine vr editor.

Unfortunately no, but steamVR has been updated recently and works quite well now with G2.

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@VictorLerp Is there anything we can do to get developer eyes on this issue?

I can rule out AA, Post Processing, FPS, and hardware issues as Iā€™ve been testing builds with each headset in our lab and the issue is only present on the WMR based platform. (Our test scene renders at 4.2-4.4ms per frame so itā€™s not FPS or 1% low issues.)

As for the previously mentioned ā€œsolutionā€ (workaround) of forcing SteamVR, thatā€™s workable in a lab, but one canā€™t expect every VR customer to force their runtime to a specific OpenXR implementation.

As Windows Mixed Reality has been discontinued by Microsoft, itā€™s unlikely theyā€™ll provide a fix for this issue. Weā€™re no longer testing w. WMR and in general we donā€™t provide runtime-specific fixes that canā€™t be reproduced with other compliant runtimes.

I understand Epicā€™s stance (to a degree), but I wouldnā€™t lay the blame solely on the M$ runtime. Our lab develops content using several COTS & proprietary engines for professional clientele, and the UE5.x product line is the only one with the added latency.

Iā€™ve been trying to determine if it shows up in a finalized shipping build too, but the UAT is refusing to generate a packaged shipping build for me right now so I canā€™t validate just yetā€¦

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I reproduce this issue on this configuration:

  • UE 5.4.4
  • Windows 11 Pro 23H2 22631.4890
  • RTX 4090
  • HP Reverb G2
  • WMR as active OpenXR runtime

I also confirm that switching to SteamVR as active openxr runtime has completely solved the stuttering I was experiencing. It seemed the stuttering was due to something breaking the motion reprojection that should be happening normally; when rendering at 75hz (what the headset seemed to be presenting to instead of 90hz), only the frame drops below that would introduce a stutter. Unable to say about latency in particular.

This was not a problem in UE4.27.2, and was most likely not a problem in UE5.1.

WMR is completely dead, if you have users that insist on using it, tell them to either use SteamVR or turn their details down very very low. Preferably both.

WMR is completely dead, if you have users that insist on using it, tell them to either use SteamVR or turn their details down very very low. Preferably both.

A great idea, if you only deal with ā€˜gamersā€™ā€¦

Please send us the approximately $200,000 to replace all of the headsets and tracked devices in each of our lab environments. Labs which donā€™t use internet connectivity, and as such are not forced to keep updating microsoft windows versions each time Microsoft wants to break something in the name of security.

I sympathize. The problem became almost unnoticeable when I turned the detail settings in the game down to as low as they would go.
We got as far as determining that the problem is probably somewhere between the interface between OpenXR and the WinMR stack, discovered that both SteamVR and lowering detail got it working, and dropped the issue, because the number of those headsets still in use are in a relatively easily countable range. I know you only had a year to prepare for that, but itā€™s been broken in Unreal for a lot longer than a year.

I donā€™t know if 5.0 or 5.1 work with WMR reasonably accurately, but 4.27 does. You might also just be able to install SteamVR on the PCs, set the XR stack to SteamVR, and use the Unreal SteamVR plugin.