Solving Ghosting/Stuttering in WMR - Not all 45fps are created equal

I'm starting this thread for those, like me, who are relatively new to VR, own a Windows Mixed Reality headset (I use the Samsung Odyssey) and are unaware or not entirely fluent in this whole arena of Asynchronous Space Warp (for the Oculus) or its "equivalent" in the WMR world: Motion Reprojection.

As a side note, I am well aware that this has been discussed in some threads, but I only recently discovered this solution after watching a YouTube video. Hopefully a dedicated thread will help others easily find it with a search here.

So... on to the problem I was having....

I have, I think by most current standards. a pretty beefy rig: as of this writing, an OC'd i-7700k, 32gig of fast RAM, a NMVe drive, and a 1080ti GPU. Without a drop in framerate as measured by the internal DCS FPS meter, I was showing a pretty steady 45fps even when running with the default "High" settings.

However, I was noticing an annoying graphics anomaly that happened during "fast" movement across by field of vision: what I would describe as ghosting of images (although I use "stuttering" in the subject field for searchability reasons, I'm not sure if this is best described that way as while this anomaly is occuring, my fps stays at a steady 45). This was most easily replicated by doing a low-level, high-g turn whilst looking at the ground below the wing. Vehicles, buildings, or trees, which moved fluidly while off my nose, suddenly looked terrible. I also got this during dogfighting when an enemy aircraft zoomed right past me. I tried messing with all the graphics options (everything from Pixel Density, to shadows, to AA and Anisotropic filtering), but nothing solved this particular problem.

Here is where I hope someone else learns from my admitted stupidity and misunderstanding of what is called Motion Reprojection. My *basic* understanding is that if your computer can't render for your headset at its native Hz rating (90 hz on the Samsung) with a matching fps (90 fps for the Samsung), the system drops your fps to half your Hz rating (thus 45 for the Odyssey) and software and/or hardware interpolates frames to get you to the equivalent of 90fps thus matching the headset refresh rate and making for a butter-smooth VR experience.

My major mistake was thinking that because I was almost always showing 45fps, Motion Reprojection was activated so I never gave it another thought as I figured it was an automatic kick-in kinda thing. I was wrong.

I discovered how to turn it on while watching a video on YouTube made by SweViver. I never heard of him, but after surfing for Pimax reviews, I ran across his channel. Anyway, he has a video on this particular subject which has changed my DCS life. In a nutshell, and you can see it for yourself in the link below, you need to turn on Motion Reprojection by doing a simple text edit of a config file. After learning this, I did a more targeted search here in the forums and found mention of this buried deep in a few threads; thus the reason for making this thread.

This *completely* solved my issue and now has me re-evaluating whether to pull the trigger on a 2080ti as, without a Pimax headset running 5k or 8k, I'm not sure if I'll see a substantial improvement over what I am now seeing with my 1080ti.... although I'll wait to see if others can hit 90fps without Motion Reprojection before I make a final decision.

Anyway... I know this is not an entirely original fix, but I'm hoping this helps those with WMR sets who are not entirely comfortable with this new frontier.

-Paul

Link to Video:

I downloaded the steam VR Beta client and edited the file following instructions from this link:

https://steamcommunity.com/games/719950/announcements/detail/1652133167137673234

I'm sad to say that it did NOT resolve the issue as you describe above for me. I too noticed the ghosting/stuttering - especially when moving my head back and forth rapidly in the cockpit.

I was "upgrading' from a rift to the Samsung and although the visuals were WAY Better in the Odyssey, for me that ghosting issue was a show stopper.

Additionally the "sweet spot" in the Odyssey was so small that I had a hard time keeping the headset positioned in the exact correct spot. After a few moments (especially when looking down at the cockpit) i noticed the headset would shift slightly and everything would be out of focus again.

I really wanted to keep the Odyssey, but these two issues were enough to warrant the return to amazon.

After putting the rift back on the colors are now desaturated and not as crisp, but the smoothness with ASW and the bigger sweet spot were a welcome return.

only my .02 cents.

I think if I spent enough time messing with the strap I could have overcome the sweet spot issue and i'm sure in time they will fix the ASW, but for now I'm back in the rift.

I downloaded the steam VR Beta client and edited the file following instructions from this link:

https://steamcommunity.com/games/719950/announcements/detail/1652133167137673234

 

I'm sad to say that it did NOT resolve the issue as you describe above for me. I too noticed the ghosting/stuttering - especially when moving my head back and forth rapidly in the cockpit.

 

I was "upgrading' from a rift to the Samsung and although the visuals were WAY Better in the Odyssey, for me that ghosting issue was a show stopper.

Additionally the "sweet spot" in the Odyssey was so small that I had a hard time keeping the headset positioned in the exact correct spot. After a few moments (especially when looking down at the cockpit) i noticed the headset would shift slightly and everything would be out of focus again.

 

I really wanted to keep the Odyssey, but these two issues were enough to warrant the return to amazon.

After putting the rift back on the colors are now desaturated and not as crisp, but the smoothness with ASW and the bigger sweet spot were a welcome return.

 

only my .02 cents.

I think if I spent enough time messing with the strap I could have overcome the sweet spot issue and i'm sure in time they will fix the ASW, but for now I'm back in the rift.

Two things I'm curious about: first... you mention the SteamVR beta. Did you activate the Windows Mixed Reality for SteamVR Beta? I'm sure you did, but for clarity sakes, they are two different things. Took me awhile to figure that one out. :)

Second, how long ago did you do this as I see you returned your Odyssey? I know there have been multiple, recent updates to WMR for SteamVR and I can only speak to the most recent version.

One thing is for sure, VR has a long way to go to make it "plug and play" for the masses....

hey Wazoo,

The Odyssey is in the box headed to Amazon today. I did the setup and testing over the weekend. It really kills me because the vis was so MUCH better in the Odyssey. Pretty sure I did Steam VR for mixed reality beta - as I had the file on my hard drive to edit with notepad ++.

Man oh man what pain to get that windows mixed reality setup too? Over 3 hours of updating windows and then rebooting computer only to have the setup process seemingly fail or stuck on "hang tight".

After all that the visuals were worth the pain, but I couldn't get over the sweet spot or ASW.

I'm so tempted to give it another shot, but my time is limited and the Rift just WORKS out of the box....

thanks for posting this for others to see.

Maybe you could take it one step further with a step by step guide.

so many moving pieces. Steam VR beta, windows MR beta... yada yada...

cheers!

I had issues with the Odyssey when I first got it. Then I redid the face mask which brought the unit closer to my head. Much bigger sweet spot, wider FOV, and I was able to take off my glasses. Made all the difference in the world. Try taking off the foam ring. If that works for You I have a thread here that shows what I did. Cheap and easily.

I find i need to force it on for it to work but the result is just amazing, 45 fps that feels like 90 with 0 ghosting

I find i need to force it on for it to work but the result is just amazing, 45 fps that feels like 90 with 0 ghosting

Force it on? Please explain.

Edit steam\steamapps\common\MixedRealityVRDriver\resources\settings\default.vrsettings

Make sure this line is set to motionvector and not auto and ofcourse remove the // infront of it.

"motionReprojectionMode" : "motionvector",

uncomment this one too"motionReprojectionTemporalEnabled" : true, I havent really done any testing with it but performance is fine so

Feels just like 90 fps to me. I got it on in X plane too, amazing there as well.

Can copy/paste

{
   "driver_Holographic" : {
       "renderTargetScale" : 1.0
   },
   "driver_Holographic_Experimental" : {
       // Motion reprojection doubles framerate through motion vector extrapolation 
       //     motionvector = force application to always run at half framerate with motion vector reprojection
       //     auto         = automatically use motion reprojection when the application can not maintain native framerate
        "motionReprojectionMode" : "motionvector",

       // Automatic motion reprojection indicator to display the mode currently selected
       //     green      = off because application can render at full framerate
       //     light blue = on because application is cpu bound
       //     dark blue  = on because application is gpu bound
       //     red        = off because application running at less than half framerate
        "motionReprojectionIndicatorEnabled" : true,
       
       // Use temporal history to get higher quality motion vectors.  motionReprojectionMode must be set to 'auto' or 
       // 'motionvector' for this setting to have an affect.
       "motionReprojectionTemporalEnabled" : true,
       
       // Some people may experience increased discomfort such as nausea, motion sickness, dizziness,
       // disorientation, headache, fatigue, or eye strain when using thumbstick controls in Windows Mixed Reality.
       "thumbstickControlsEnabled" : false, // true = use thumbsticks for artificial turn/move, false = default application thumbstick behavior
       "thumbstickControlsReversed" : false,
       "thumbstickTurnSmooth" : false,
       "thumbstickDeadzone" : 0.25
   },
   "NoInterEyeRotation" : {
       "DOOMVFRx64.exe" : true
   }
}

I just gave it a try.

At high altitudes it worked and the cockpit felt amazing/absolutly smooth(locked 45fps), but I still have double vision on the ground. (~25fps)

And when zooming in/out on the map, the whole image is garbage for me. :/

But I also had shadows on low and not on flat, so maybe that's the difference.

.Impact;3655438']I just gave it a try.

 

At high altitudes it worked and the cockpit felt amazing/absolutly smooth(locked 45fps), but I still have double vision on the ground. (~25fps)

And when zooming in/out on the map, the whole image is garbage for me. :/

 

But I also had shadows on low and not on flat, so maybe that's the difference.

Thats your computer not being up to the task im afraid. Going to have to lower your settings

I like my shadows :)

And its totally fine a long as my head stays in the same position, which it does usually.

Besides that, even at locked 45fps you could still see many artefacts close to the canopy frame, while using the flashlight and like mentioned, it made the F10 map totally unusable for me :/

Seems that as long as there is a uniform movement its fine, but when moving pixels suddenly "appear" from behind a canopy strut (e.g. in helicopter cockpits.), it needs some frames to smooth the motions, so there is always some lag/artefacts in those areas.

Still a nice setting to try though.

.Impact;3656731']I like my shadows :)

And its totally fine a long as my head stays in the same position, which it does usually.

 

Besides that, even at locked 45fps you could still see many artefacts close to the canopy frame, while using the flashlight and like mentioned, it made the F10 map totally unusable for me :/

Seems that as long as there is a uniform movement its fine, but when moving pixels suddenly "appear" from behind a canopy strut (e.g. in helicopter cockpits.), it needs some frames to smooth the motions, so there is always some lag/artefacts in those areas.

 

Still a nice setting to try though.

I'm generally busy looking elsewhere so I hardly ever notice. In fact I didn't until I startet looking for it. Everyone is different though. I'd say apart from the map of course that I wasn't aware of I would call it very minor issues that really does not impact visuals and the experience in any way compared to what you gain. Hopefully the map issue will be fixed.

.Impact;3655438']I just gave it a try.

 

At high altitudes it worked and the cockpit felt amazing/absolutly smooth(locked 45fps), but I still have double vision on the ground. (~25fps)

And when zooming in/out on the map, the whole image is garbage for me. :/

 

But I also had shadows on low and not on flat, so maybe that's the difference.

under 45 fps motion vector won’t work...so it is normal that you have problems at 22fps

if you read the instructions on the settings text file you can see that you can enable a coloured indicator so to see if you are cpu or gpu limited or if reprojection is off because under 45fps(red indicator )

Thanks Wazzoo, that made a massive difference on my new HP Reverb. Very clearly explained also. Thanks heaps.

Thanks Wazzoo, that made a massive difference on my new HP Reverb. Very clearly explained also. Thanks heaps.

Awesome. Glad you found it helpful.

How you liking the Reverb?

Seems like a killer HMD for simming.

Is this even necessary now? With the WMR for SteamVR Beta version, you can uncomment the highlighted line below out:

{

“driver_Holographic” : {

// Increase back buffer size so that larger superscale values do not get a resolution reduction

“renderTargetScale” : 2.0

},

“driver_Holographic_Experimental” : {

// “motionReprojectionMode” : “auto”,

@Willie, here is a good site that has a bunch of optimization info for DCS and VR. https://vr4dcs.com/

Idiot question, but can I please just check that this wont apply to Rift S as that isnt a WMR headset?

Thanks

Edit steam\steamapps\common\MixedRealityVRDriver\resources\settings\default.vrsettings

 

Make sure this line is set to motionvector and not auto and ofcourse remove the // infront of it.

 

"motionReprojectionMode" : "motionvector",

 

uncomment this one too"motionReprojectionTemporalEnabled" : true, I havent really done any testing with it but performance is fine so

 

Feels just like 90 fps to me. I got it on in X plane too, amazing there as well.

 

Can copy/paste

 

{
   "driver_Holographic" : {
       "renderTargetScale" : 1.0
   },
   "driver_Holographic_Experimental" : {
       // Motion reprojection doubles framerate through motion vector extrapolation 
       //     motionvector = force application to always run at half framerate with motion vector reprojection
       //     auto         = automatically use motion reprojection when the application can not maintain native framerate
        "motionReprojectionMode" : "motionvector",

       // Automatic motion reprojection indicator to display the mode currently selected
       //     green      = off because application can render at full framerate
       //     light blue = on because application is cpu bound
       //     dark blue  = on because application is gpu bound
       //     red        = off because application running at less than half framerate
        "motionReprojectionIndicatorEnabled" : true,
       
       // Use temporal history to get higher quality motion vectors.  motionReprojectionMode must be set to 'auto' or 
       // 'motionvector' for this setting to have an affect.
       "motionReprojectionTemporalEnabled" : true,
       
       // Some people may experience increased discomfort such as nausea, motion sickness, dizziness,
       // disorientation, headache, fatigue, or eye strain when using thumbstick controls in Windows Mixed Reality.
       "thumbstickControlsEnabled" : false, // true = use thumbsticks for artificial turn/move, false = default application thumbstick behavior
       "thumbstickControlsReversed" : false,
       "thumbstickTurnSmooth" : false,
       "thumbstickDeadzone" : 0.25
   },
   "NoInterEyeRotation" : {
       "DOOMVFRx64.exe" : true
   }
}

This should be pinned to be honest, it's a source of confusion for all SteamVR users.

Keep in mind, after any updates of SteamVR, it will overwrite and comment it back out - so you should confirm it's still set how you want it after an update.

And as mentioned, this doesn't fix everything, if you still get lower FPS then it's because of CPU/GPU, etc...

edit: this is not in my file motionReprojectionTemporalEnabled - is this a legacy setting ?

edit: this is not in my file motionReprojectionTemporalEnabled - is this a legacy setting ?

Is this even necessary now? With the WMR for SteamVR Beta version, you can uncomment the highlighted line below out:

 

{

 

“driver_Holographic” : {

 

// Increase back buffer size so that larger superscale values do not get a resolution reduction

 

“renderTargetScale” : 2.0

 

},

 

“driver_Holographic_Experimental” : {

 

// “motionReprojectionMode” : “auto”,

 

@Willie, here is a good site that has a bunch of optimization info for DCS and VR. https://vr4dcs.com/

Thanks Shogun, indeed that’s an awesome link. I’m getting started on tonight. Thanks.

So I had bad ghosting - I was running PD 1.0, SS 100%

No shadows, 2x msaa

I tried motionvector, auto.

No joy.

Tonight I moved PD to 1.5, turned off msaa, commented out the auto, etc...

No ghosting, looks great

Well still some ghosting. Esp on ground. Not ideal but not much can do.

I honestly think this is going to happen until we get 3080 series cards.

Can't wait

I'm sorry to say that this initial post is actually incorrect, as it is based from information from early 2018. Motion reprojection is enabled by default in SteamVR/WMR as of November 2019 - the fix mentioned here just enables a new experimental version of it, which some feel looks better than the default reprojection mode. You can see Thud's excellent VR guide for more information: https://vr4dcs.com/2019/09/10/reverb-settings-for-dcs/

TO REITERATE, IF YOU CAN'T MAINTAIN 90FPS OR ABOVE IN VR ON A 90HZ HMD, REPROJECTION IS AUTOMATICALLY ENABLED, AND YOU WILL INDEED SEE GHOSTING (also referred to as stuttering, juddering and a bunch of other vague terms)

Now, there is a way to get around this apparently - disable reprojection entirely. However, while this should remove ghosting, there are a few issues:

1.) I'm not sure it's possible to disable ghosting with WMR/SteamVR devices. Would love somebody point me in the direction of how to do this with the latest versions of SteamVR and WMR.

2.) If you do disable it, which apparently is possible on the Oculus HMDs and older versions of SteamVR, you will experience massive smoothness issues when turning your head or watching the displays. Expect it to jump around and stutter heaps.

One thing that does seem to help for WMR owners is to run at 60Hz, and then lower your graphics details and resolution until you can hit 60fps solid. Unfortunately DCS looks terrible as a result.

I'm getting a bit tired of the misinformation about VR these days, with non-technical people giving out incorrect information that leads to others wasting hours of their time. I understand their heart is in the right place, but as a former technology journalist I always ensure that the information I put out is correct. And if it's not, I'm happy to be corrected.

TLDR: If you can't run the game at the HMD's refresh rate, you're going to see ghosting from reprojection. And you need a PC from the year 2030 to be able to do so on the Reverb.