OpenXR Guide - Deprecated - This time for real (▀̿Ĺ̯▀̿ ̿)

[markturner1960]

2 minutes ago, edmuss said:

I wouldn't expect you to be below 60fps with a 3090 hence you'll never get into the MR overhead spiral I'm describing

Out of interest, what appGPU and postGPU frametimes are you getting (reading from the OXRDT performance overlay).

when I am back at my machine at the weekend I will post these up. I am not using any frame time of FPS counters currently, so all of my opinions are purely subjective currently! 

[DeltaMike]

7 hours ago, javelina1 said:

same here, not giving them up.  They look great with my VR setup. 

Flying with OpenXR and Toolkit just fine.  120%, MR, no upscaling, and sharpening at 60%.  The rest of DCS at high or above.  I toggle between 30 and 45 FPS.  Smooth and fluid.  (with the Toolkit, 30 IS the new 45).  Note, this is with the Apache. With other mods, I keep consistently at 45.

 

Perfect example of what I'm talking about.  As Lynyrd Skynyrd said, "turn it up." 

2 hours ago, A.F. said:

I have my G2 set to 60 Hz and achieve 50 to 60 fps at 50% resolution.
However, the picture is not smooth at all.
If another F14 is flying next to me and I look out of the cockpit from the side, the image jerks so much that I get a headache after a while.
It doesn't help when I switch on MR. It has no effect.
I think something is completely wrong here.

(By the way, the topic already haunts my dreams )

There's a world of difference between "60" and "50-60"  which Edmuss explained in detail above. 

Let me guess -- 2000 series?  Better yet, post up your specs and settings and let's get ya tuned up.  

ETA:  weird being right all the time... lets see a screen shot of your settings.  2080S is plenty, you'll be zipping around in no time

Edited April 20, 2022 by DeltaMike

[A.F.]

Thank you for your answer !
I will hopefully be able to post the screenshots tomorrow.

[DeltaMike]

@Rosebud47 Good article on microstutter here

Relevant to G2 --

• We can't turn "v-synch" off.  It's forced on, to either 90hz or 60hz
• Nobody's gonna put a variable rate monitor in a VR headset, apparently it makes ya puke

I think it follows, then, that you have to be close if you want those stutters to go away.  Close to your refresh rate, or to a --ahem-- whole-number-fraction of it

From what I can gather, to the extent the G2 has "v-synch,"  the headset sends a signal down through the VR stack to let the CPU know when it's ready for a new frame.  If you lock your framerates externally, for example with Chill, then your GPU driver is also sending a signal to the CPU, outside the VR stack, when it feels it's ready for a new frame. 

Your CPU, then, is getting bossed around by two entities that never talk to each other.  If it's anything like the place where I work -- and it sounds like it is -- that's non-optimal.  The guy who wrote the OXR Toolkit says that results in "non-deterministic latency."  I don't know what that is, but it sounds.... like, bad.

Where motion reprojection come in, is when you're running at 45fps, and your refresh rate is 90hz, you have two options:

1. Watch every frame twice
2. Watch a new frame every time, realizing that your GPU is just gonna make up what it thinks every other frame should look like

In Windows, motion reprojection does a great job with those synthetic frames, and also locks your framerate from within the VR stack. So if you can consistently meet that frame rate, it looks fantastic actually.  Solves a lot of problems in WMR/SVR.  In OXR... it has some cool features but, I think it needs a little more time in the oven myself.  

Edited April 20, 2022 by DeltaMike

[DeltaMike]

I think the problem is, we keep forgetting, if you're gonna use MR, you have to keep your frametimes well above minimum, otherwise (in the case of WMR) your motion reprojection is always going to be switching on or off, or (in the case of OXR) you're gonna be constantly flipping back and forth between 30 and 45fps.  That's why the MSFS folks keep saying "30 is the new 45."  Better to lock in 30 in MSFS.  We can still shoot for 45 in DCS.  But we have to meet or beat that every frame for it to work.  

[edmuss]

20 minutes ago, DeltaMike said:

So if you can consistently meet that frame rate, it looks fantastic actually. 

This is what I've been using for a while now

Really not hard to get >60fps, the big stumbling block is the refresh rate flicker if you're sensitive to it.

[Gabi_tro]

Any idea why I get this error?

[DeltaMike]

^which leads me to think I'm just not doing it right in OXR.  I'm currently tuned to 46fps, I need to be running closer to 50 to make it work I think.  If I could just let go... let go of those darn shadows....

[TylerPL666]

Yesterday I hunt for anything that can link WMR with SteamVR and found files named "steamvr.vrsettings" and rename them in those dirs:

X:\Program Files\Steam\config

X:\Users\[YourName]\AppData\Local\openxr

Think that even with Steam shot down, and playing in WMR only still somehow uses those settings. After renameing it my image stop jitterings. Worth to try at least, maybe there are still some old drivers in those files.

[edmuss]

3 minutes ago, DeltaMike said:

^which leads me to think I'm just not doing it right in OXR.  I'm currently tuned to 46fps, I need to be running closer to 50 to make it work I think.  If I could just let go... let go of those darn shadows....

For reference: -

When locked to half refresh rate the vsync will only sync rotational movement, that is looking around will be smooth but translations won't be as smooth. Easy way to test this is to focus on the fire extinguisher handles in the A10C and slide your head sideways, you'll see ghosting of the textures but turning your head you won't.

Motion reprojection eliminates this translational ghosting which gives an ultimately smooth display.

Achieving refresh rate allows the vsync to work on both rotational and translation without the extra layer of computation from the reprojection.

[Gabi_tro]

37 minutes ago, Gabi_tro said:

Any idea why I get this error?

pls

[edmuss]

23 minutes ago, Gabi_tro said:

pls

I've never had any errors so I'm afraid I'm rubbish at troubleshooting them.

Off the top of my head: -

Try reinstalling the three OC_ACC files into the bin folder.

Try disabling the OpenXR ToolKit via the companion app. On some hardware/software configurations it causes issues for some reason unknown.

[DeltaMike]

55 minutes ago, Gabi_tro said:

pls

I haven't seen that one, you'll need to ask em on the discord. pm sent. 

@edmuss i haven't tried fixed foveated yet, wonder if that might put me over the top.  The 60hz flickering doesn't really bother me.  It's bad in the cliff house but hardly notice it in game

Eta nm I would need dx12

Edited April 20, 2022 by DeltaMike

[Gabi_tro]

1 minute ago, DeltaMike said:

I haven't seen that one, you'll need to ask em on the discord. pm sent. 

thanks ..how do I find them on discord?

[DeltaMike]

I sent you the link, check your messages

 

[edmuss]

The FFR is good for 1ms or there about on the quality wide preset (the best quality/least performant). I would hope that at 100% you should be getting 75+ fps.

[Rosebud47]

vor 1 Stunde schrieb DeltaMike:

I think the problem is, we keep forgetting, if you're gonna use MR, you have to keep your frametimes well above minimum, otherwise (in the case of WMR) your motion reprojection is always going to be switching on or off, or (in the case of OXR) you're gonna be constantly flipping back and forth between 30 and 45fps.  That's why the MSFS folks keep saying "30 is the new 45."  Better to lock in 30 in MSFS.  We can still shoot for 45 in DCS.  But we have to meet or beat that every frame for it to work.  

That´s why locking to 45 in OXR Toolkit is the only option I use there. 45 is 45 to me.

There is also no particular v-synch function in the VR headset. The synchronization is done by reprojection or not at all ( as long as there is not enough performance to maintain 90fps ).

"non-deterministic latency" is a nice expression. I understand it to describe the situation with frames, we have without reprojection. It means it is not foreseeable for how long one frame is visible in a moment ( that moment is between 11ms and above ) or let´s put it in another way: how long one frame needs to be processed to render a scene.  

Reprojection makes the latency determenal as long as 45FPS could be maintained in every scene to render. I could reach that +/- 1 or 2 frames with a 3080Ti , well ... the Apache is tanking  some more frames and the Marianas... uhhh?

 

vor 2 Stunden schrieb DeltaMike:

1. Watch a new frame every time, realizing that your GPU is just gonna make up what it thinks every other frame should look like

  Don´t be angry with me, when making a little fun of that, but that´s, what Palmer Luckey told everyone, when Oculus first came up with Asynchroneous Time Warp ( reprojection ). The kids actually believed, that there is a magic software, which knows in which heading you turn your jet, before you know it by yourself 

 

[edmuss]

35 minutes ago, Rosebud47 said:

There is also no particular v-synch function in the VR headset. The synchronization is done by reprojection or not at all ( as long as there is not enough performance to maintain 90fps ).

Yes there is in openxr (and I think in openvr), it's just in the background and you don't have any control over it.

edit: this is why openxr is smoother at 45 than 50, because you've hit the vysnc fraction.

Edited April 20, 2022 by edmuss

[Rosebud47]

vor 21 Minuten schrieb edmuss:

Yes there is in openxr (and I think in openvr), it's just in the background and you don't have any control over it.

edit: this is why openxr is smoother at 45 than 50, because you've hit the vysnc fraction.

 

You don´t get 50FPS with reprojection. Withou reprojection 45 or 50fps isn´t smooth at all.

[edmuss]

I'm talking about reprojection disabled.

45 fps is smooth on rotation if it's locked exactly to 45fps*, on translation it's not; you need fps > refresh rate or reprojection enabled to smooth translation.

Translation can be in any of the three axes X translation from rolling and Z translation from forward flight but I suspect that you struggle to get sufficient Y translation to notice in DCS.

*not best practise locking the framerate outside of the render stack.

[The_Nephilim]

How can I lock the FPS at 30 with motion reprojection with OpenXR? I see you can enable it but how do I specify what fps I want to run at I am lost here?

[edmuss]

Use the motion reprojection options in the in-game menu from OXRTK. You can choose unlocked, 45, 30 or 22.

[A.F.]

Is this something for us who use Leap Motion?

https://mbucchia.github.io/OpenXR-Toolkit/hand-tracking.html

[edmuss]

Interesting, might have a play with that. I have read that the DCS gloves don't follow the OXRTK hands precisely.

Will have a play when I've got time

[The_Nephilim]

2 hours ago, edmuss said:

Use the motion reprojection options in the in-game menu from OXRTK. You can choose unlocked, 45, 30 or 22.

OK I thought so but when I set it to 30 it does not lock at 30fps, is something broke here or did I do it wrong?