OpenXR for Varjo AERO using OpenCompositeACC mod: works great, very smooth

[peachmonkey]

(updated: June 10th, 2022)

hey, guys,

thanks to @mimikiwi on Discord and other super cool guys we figured out how to make OpenXR work for Varjo Aero.

The performance gets a serious bump in the 'smoothness' department. There are no jitters/tears, the performance is super smooth. You can still see the blur looking outside the cockpit on left/right at low level, but it beats the jitter mess that OpenVR introduces.

To make it work for Varjo Aero:

1) download the mod from https://gitlab.com/Jabbah/open-composite-acc/-/releases  (latest version 0.6.1 https://gitlab.com/Jabbah/open-composite-acc/uploads/d802bd460c18ee06e832bb2d6582209c/OCXR_WMR_ACC_v0.6.1.zip)

The above links are old, the .zip download still works but it has older files, so I recommend you navigate to the latest release page: https://gitlab.com/znixian/OpenOVR/-/tree/openxr

Download file (x64bit):  openvr_api.dll    (link: https://znix.xyz/OpenComposite/download.php?arch=x64&branch=openxr)

This file provides a redirect mod from openVR to OpenXR framework in Varjo application ecosystem.

2) place the downloaded openvr_api.dll  in to  \bin\ folder in DCS  (or use a mod installer):

Important:  openvr_api.dll is part of the DCS core install (for OpenVR support), hence it already exists in \bin\ and the system will prompt you to over-write it. Back up the existing openvr_api.dll file if you want to revert back to OpenVR/SteamVR support. Then go ahead and over-write it with the downloaded file. Please note that any subsequent updates to the game may/will over-write this file with the ED provided one, hence check after each update whether or not you need to over-write it again. If you forgot to back up the original you can always restore it via Steam file check integrity of the whole DCS game (it'll re-download the original file).

3) create a file called opencomposite.ini  in \bin\ folder. Some people need this file, some don't, but on my system I get an error if this file isn't present when launching DCS.  Copy/paste the following contents in to the file using the notepad app:

;Mirror mode outputs a shared texture for use by OBS plugin
;mirrorMode=disabled

;Performance stats enables writing of performance stats
; If enabled press F11 to start stats capture to file
; File is currently output to \Program Files (x86)\Steam\steamapps\common\Assetto Corsa Competizione\AC2\Binaries\Win64\teststats.csv
;performanceStats=disabled

;Hidden area mesh fix now is autogenerated you no longer need to put in manual values see changeling V0.6.1
;enableHiddenMeshFix=enabled

;Use OpenXR layers to handle GUI overlays and HUDs, if set to false will render internally directly onto swap chain before submitting
enableLayers=true

forceConnectedTouch=disabled
renderCustomHands=disabled

4) Open Varjo Base application and make sure OpenXR is enabled

5) make sure OpenVR is DISABLED in VarjoBase  (doing so may affect other SteamVR games you play, so remember to switch it back ON if you're playing  games that rely on OpenVR)

6) Make sure V-sync is disabled in Varjo Base. Otherwise you'll get a lot of ghosting in-game.

7) run the game with  "dcs.exe --force_steam_VR"  (create a shortcut, add the --force_steam_VR line at the end. Make sure it's indeed dcs.exe in the shortcut and not dcsupdater.exe or some other file names)

Note1:  If there are problems with the aspect ratio of the DCS (tilt your head left or right and the whole picture skews to the left or to the right) you may need to re-run the WMR debug tool to resolve the aspect ratio problems. It was necessary to run it when we figured out the support for OpenXR back in March. However, with the latest DCS builds the need to run WMR tool is no longer there.

**************IF you need to run /or/ re-run the tool:**************
a) delete a single headsetname.lua file from %:\Users\username\SavedGames\DCS\  <-- this file will exist ONLY if you ran the WMR debug tool before. If you never used the correction tool then the file won't be there, so proceed to b) below.
Note2: headsetname <-- this could be Quest2, or some HP or Dell in its name, or HEDY.lua (it changes for some reason). You need to have the "show file extensions" option turned on in the File Explorer in order to see the .lua extension. But it'll be the only .lua file under \SavedGames\DCS\  so just go ahead and copy it to some other folder for backup purposes and then delete it from SavedGames\DCS\
b) make sure the autoexec.cfg file with the below config line exists in %:\Users\yourname\Saved Games\DCS\Config\ folder. If it doesn't exist, just create one with notepad app and copy/paste the following line into it:
force_cross_eye_recovery_tool = true

*****************************************************************************

8 ) Since with OpenXR the SteamVR app is no longer launched/used the render resolution is controlled by Varjo Base (the ppd numbers) and it doesn't offer any option for custom resolutions, i.e. it's either at 35ppd or 37ppd, etc. So, in order to set the custom resolution you must use the OpenXR Toolkit developed by a @mbucchia. 

The toolkit can be downloaded here: https://mbucchia.github.io/OpenXR-Toolkit/

Please read through the manual in the above link, it explains how to launch it and all the settings in the tool-kit.

In the tool-kit you have 2 options for resolution control:

•     System tab / Override resolution: Enable overriding the overall OpenXR target resolution. You can just set whichever vertical/horizontal numbers you need to achieve the desired result.
•     Performance tab / Upscaling:  OFF (default), NIS, FSR
  • allows you to reduce the 'size' of the screen, i.e. lower the resolution (you'll see ver/horizontal numbers there)
  • then when either NIS or FSR selected, the selected algorithm will upscale the picture to 100% resolution (either the one set in VB, i.e. ppd, or in System/override resolution tab of the toolkit)
  • it also allows you to modify the sharpness. I.e, even if you don't reduce the 'size' you can still add sharpness anyway (you must select either NIS or FSR for the sharpness setting to become available)

Color Saturation/Sharpening:

1) use OpenXR toolkit from above, there are multiple options available (read the manual)

2) Reshade 5 doesn't work with OpenXR.

 

Edited June 13, 2022 by peachmonkey

[mimikiwi]

It's awesome stuff indeed. For more info and kudo's to the original finder I am crossposting the original forum link here. It should work for most HMD's. We just figured out the best way to set it up for the Aero (and XR3/VR3 probably too):

 

 

[peachmonkey]

@mimikiwi

the latest version of OpenXR toolkit works out of the box, no need for any custom dll's..

 

https://mbucchia.github.io/OpenXR-Toolkit/ (v1.0.4)

 

 

 

 

Edited March 25, 2022 by peachmonkey

[Brainfreeze]

On 3/24/2022 at 11:51 AM, peachmonkey said:

@mimikiwi

the latest version of OpenXR toolkit works out of the box, no need for any custom dll's..

 

https://mbucchia.github.io/OpenXR-Toolkit/ (v1.0.4)

 

 

 

 

 

Do you mean there is no need to do step 1) and 2) on your top/1st post?

[Baldrick33]

3 hours ago, Brainfreeze said:

Do you mean there is no need to do step 1) and 2) on your top/1st post?

No I believe that is to get OpenXR to work. The Toolkit referred to provides additional configuration options on top.

[Supmua]

I’m away but will have to try this when I get home later today. So you want to run DCS in SteamVR mode while turning off OpenVR?  This sounds like Revive but for OpenXR instead of Oculus runtime.

Currently I rely on Reshade 5 filters to provide the best possible image quality (sharpening, color balance, brightness, etc.), but let’s see if this can give a performance lift while retaining good visuals. 

[edmuss]

The openxr toolkit has saturation, contrast and brightness adjustments built in

I've not seen the need to sharpen it, I aliken it to having taken a gauze material away from my eyes, everything is just that much sharper.

[Supmua]

Oh I’m familiar with OpenXR toolkit, been using it with MSFS since they added FFV.  They have sharpening with upscaling NIS/FSR but nothing beats Reshade’s lumasharpen so far, it’s like having a free sharpening with no detrimental effect on shimmering. 

[Supmua]

OK, I've spent 1.5 hours with this thing.  So far it's not bad but I have some reservations.

 

Pros:

1. Performance friendly.  It can moderate reduce your GPU frametime (or significantly if you don't know how to optimize your settings), thus results in framerate increase (provided that you're not CPU limited, which can occur in some situations in DCS).

2. Image quality in the inner circle is crystal clear, since it's typically 100% rendering  or even higher (depending on the setting on the Varjo app).  This is slightly better than my OpenVR/Reshade setting since I typically downsample to around 80%.

 

Cons:

1. It's sort of a hack, kinda like OpenXR wrapper for OpenVR, so stability can present an issue.  At present it is crash-prone.  For example, attempt to change upscaling NIS/FSR or sometimes image processing, FOV, wordscale, would results in perpetual crash--this can be recovered by running OpenXR Toolkit companion app and enable safe mode, then press CTRL+F1+F2+F3 to delete all settings.  What's worse is that attempt to reduce PD results in perpetual crash, which requires editing the options.lua and manually change PD back to 1.0.

2. No good way to set rendering resolution at present, you rely on Varjo app for this and options are limited (6 settings, nothing in-between) which prevent fine tuning to get just the right frametime for your particular setup (With SteamVR you can specify percentage in digit numbers of your choice).  Now I typically run the Aero resolution at Higher setting since web browsing or movie watching at this res looks awesome but the performance in this mode is too taxing in DCS--worse than my current OpenVR/Reshade setup.  I have to lower it to High setting, to get the performance that is better than my typical settings.

3. Ground and distance detail is no match for OpenVR/Reshade.  Since fix foveated rendering relies on rendering outer area at low resolution, you can imagine what would happen to distance detail when you look further up/down/left/right--compared to non-FFV where the ground detail is clear all the way up to the horizon, although this will probably change when we get dynamic foveated rendering.

 

For the time being, I'll keep using it and see what happens.

Edited March 27, 2022 by Supmua

[peachmonkey]

3 hours ago, Supmua said:

I’m away but will have to try this when I get home later today. So you want to run DCS in SteamVR mode while turning off OpenVR?  This sounds like Revive but for OpenXR instead of Oculus runtime.

Currently I rely on Reshade 5 filters to provide the best possible image quality (sharpening, color balance, brightness, etc.), but let’s see if this can give a performance lift while retaining good visuals. 

1) yup, running it through steamVR framework, however it's using OpenXR renderer instead. For that OpenVR must be disabled in Varjo Base, however the --forceSteamVR makes sure the HMD tracking works through it. It's similar to opencomposite hack that was done for Oculus devices...

2) unfortunately, Reshade 5 won't work with OpenXR.  If you want to get that additional color saturation + sharpening you must use the OpenXR Toolkit. Just download the latest v1.0.4 and install it, there's no need to replace DLL's anymore, it's working out of the box.  https://mbucchia.github.io/OpenXR-Toolkit/

Just now, Supmua said:

3. Ground and distance detail is no match for OpenVR/Reshade.  Since fix foveated rendering relies on rendering outer area at low resolution, you can imagine what would happen to distance detail when you look further up/down/left/right--compared to non-FFV where the ground detail is clear all the way up to the horizon, although this will probably change when we get dynamic foveated rendering.

FFR doesn't really work with DCS in this toolkit version, or if it works it's very wonky, I wouldn't turn it on at all.

[Supmua]

FFR does work, perhaps not as 100% intended but check this out.  Non-zoom snapshot from my phone.  The area inside the red circle is where the inner ring is, notice how it's completely non-pixelated, compared to rest which represents the outer area.  The further away from the inner area, the more pixelated it becomes.  You can even see these changes when switching presets around between performance/quality, wide/balanced/narrow.

 

Edited March 27, 2022 by Supmua

[Supmua]

Ok some more findings below (with FFR off).

 

1. At Higher setting on the Varjo Aero, the ground detail is on par with OpenVR/Reshade and the cockpit is sharper due to higher rendering res.  This costs 10-12 fps compared to High setting (which looks similar to my Vive Pro 2 in terms of central clarity).

2. With Vertical sync on (Varjo app), juddering is completely eliminated provided that you can maintain 45+ fps, still see slight motion blur similar to movies when camera pans around.  It is completely smooth flying low.  This costs around 10 fps which is substantial if you go with Higher setting.

3. There is extremely minimal shimmering at higher setting, and this is better than OpenVR/Reshade at lower samplings to achieve similar fps.  There is no shimmering on buildings (tested in Dubai with strong sun), only noticeable on the shoreline and even that is minimal.  Virtually no shimmering inside the cockpit around text borders, etc. (I do get a bit of that with OpenVR/Reshade option since rendering resolution isn't optimal to achieve good fps).  And this kind of visuals is quite stunning.

4. FFR only saves 2-4 fps, so it's probably not working as intended.

5. After eye calibration, the lua file for this is named HP Reverb G2 (hah!) rather than the usual Hedy for the Aero.

So right now Higher setting it is for me as the image quality is super good, and still this can get even better with a sharpening filter.  FPS is still a bit of a concern with congested maps, but more testing to do.

Edited March 28, 2022 by Supmua

[edmuss]

Im not sure if it will translate equally with the varjo but with my G2 I can drop the render resolution down to 75-80% with minimal loss of clarity but with a fairly healthy bump in framerate

[Supmua]

29 minutes ago, edmuss said:

Im not sure if it will translate equally with the varjo but with my G2 I can drop the render resolution down to 75-80% with minimal loss of clarity but with a fairly healthy bump in framerate

I'm not sure if OpenXR dev tool would work with the Aero, since it's meant for WMR headset, I'll see if I can test this.  So far I've tried changing PD which caused instant crash on start, and also changing Varjo's rendering res on its own app (only 6 settings).

 

Edit:  Nope.  Managed to install OpenXR dev tool and runtime, reduced rendering res to 20%.  Zero changes observed.  It seems the rendering goes through Varjo's own OpenXR pipeline not WMR's runtime, so the scaling needs to be provided by either Varjo or Toolkit developer themselves.  I also tried scaling via NIS and FSR (OpenXR Toolkit), which resulted in instant crash or perpetual crash upon restart.

 

Or maybe, just maybe ED could develop its own OpenXR wrapper.  This might just solve all the compatibility issues.

Edited March 27, 2022 by Supmua

[dburne]

1 hour ago, Supmua said:

I'm not sure if OpenXR dev tool would work with the Aero, since it's meant for WMR headset, I'll see if I can test this.  So far I've tried changing PD which caused instant crash on start, and also changing Varjo's rendering res on its own app (only 6 settings).

 

Edit:  Nope.  Managed to install OpenXR dev tool and runtime, reduced rendering res to 20%.  Zero changes observed.  It seems the rendering goes through Varjo's own OpenXR pipeline not WMR's runtime, so the scaling needs to be provided by either Varjo or Toolkit developer themselves.  I also tried scaling via NIS and FSR (OpenXR Toolkit), which resulted in instant crash or perpetual crash upon restart.

 

Or maybe, just maybe ED could develop its own OpenXR wrapper.  This might just solve all the compatibility issues.

 

ED supporting Open XR natively is really the key imho. I see what it along with TXAA does for MSFS 2020 and I would so love to see that with DCS.

However I thought I saw somewhere where the developer of Open XR was working on it working with the Varjo Aero? Maybe I am confused on that one, seems I saw that somewhere on Discord and that it maybe released in early April...

Maybe this is what I was thinking of though:

 

Edited March 28, 2022 by dburne

[dburne]

There is also Eye Tracking with Foveated Rendering coming with the Open XR Toolkit for the Aero. Now if he could get this to work with DCS... I would be set!

 

Edited March 28, 2022 by dburne

[Supmua]

There is no question that there is fps gain using OpenXR vs OpenVR (at least through Steam).  However, losing SteamVR’s functionality can also be a bummer (losing windows overlay, fpsVR, Reshade support, etc.).  Image quality through OpenXR is superb but without sharpening it lacks a little pop.  Sort of like calibrating your home theater TV with zero sharpening, which may be great for video purists in terms of movie watching.  But for gaming, a little extra sharpening can add a bit to the experiences.

 

One thing I haven’t tried is OpenXR via SteamVR, not sure if it’ll work though.  Perhaps tomorrow.

Edited March 28, 2022 by Supmua

[peachmonkey]

@Supmua

thank you for doing all the testing! I'm running VB at Medium (33ppd) and my experience is very pleasant on my system. Heck, the DCS VR is so much better that I haven't played IL2 for about a week now, and have no interest in going back to it either...

Vsync On = definitely need to maintain 90fps to get rid of the ghosting, but even with it's being Off the smoothness is still very much pleasant compared to openVR.

OpenXR with SteamVr = if you figure it out that'd be awesome. In my tests as soon as you disable OpenVR in VarjoBase the SteamVR stops seeing the headset altogether....

[Supmua]

Imo, the images I can get from the Vive Pro 2/Reshade look very close the Aero in High setting (without sharpening) minus the peripheral clarity/glare/micro contrast due to fuzzy fresnel lens vs crystal-like aspherical lens.  It is only when I run the Aero in higher mode (37 PPD—which is actually less since they count dynamic foveated rendering that is automatically applied in Varjo base app, so only true for that app) that I can clearly see a major step up in visuals compared to my older headsets.

Edited March 28, 2022 by Supmua

[Supmua]

More observation.

1. It doesn't care if OpenVR setting is on or off in the Varjo app, but Varjo's OpenXR must be on as it will not use OpenXR via SteamVR.  I had SteamVR running concurrently and everything was fine.  So this makes me think that it will *not* work with headsets that rely on SteamVR for OpenXR (namely Valve Index, Vive Pro series), someone can prove me wrong as I’m too lazy to dig out my old headsets from the basement to test this.

2. It doesn't help lowering CPU frametime.  For example, in Apache runwaystart Marinara map my GPU frametime was 20 ms which would typically yield 45 fps, but CPU frametime was up to 25 ms resulting in final fps of 30 (1:3 reprojection instead of 1:2).  I'm going to see if lowering rendering res affect CPU frametime or not.

3. It doesn't play nice with Reshade.  Deleting Reshade completely allows me to play with FSR scaling (which looks ugly on the Varjo btw).  It still wants PD at 1.0, else instant crash.

 

Edit:   lowering rendering resolution via Varjo app setting doesn't help improve CPU frametime.  Flying over the carrier to the right of the airport instantly gave me a CPU frametime spike over 30 ms.  In this type of situation, not even an RTX 4090 will help as my CPU is the bottleneck.  Most of the time when you're up in the air however, GPU is typically taxed more than CPU but not by much with this map.  It also seems that 32GB RAM may not be enough, after 1.5-2 hr of playing CPU frametime would stay at 30 ms when I landed on the ground (Syria) and CPU RAM usage was saturated at 31.9 GB (out of 32).  Not sure if this was intended or due to memory leak.

Edited March 29, 2022 by Supmua

[AlexCaboose]

Will have to test this out tomorrow.

[Supmua]

Ok the final verdict from me, been flying as much as I could whenever I’m home.  If you haven’t tried this with the Aero, you’re missing out…big time.  The ability to use 100% rendering resolution on the Varjo Aero while retaining decent fps just wasn’t possible before until now.  And the visuals are absolutely amazing at this resolution, note that I’m also using Higher mode on the Aero instead of default.  Everything just looks crisp, with next to nothing aliasing artifacts.  Not only that, things are bound to get better once foveated rendering works properly…and dynamic foveated (eye tracking) is also coming soon at least for the MSFS counter part.  Detailed FPS option from the toolkit will display CPU and GPU frametimes, and more for those who like to tinker—so fpsVR is not needed.  Sharpening is possible via NIS/FSR setting even at 100% scaling, it’s not as good as Reshade’s lumasharpen in terms of making things pop, but the overall visuals look more natural (a tad dimmer and less vibrant) rather than artificial.  The gamma is slightly different in OpenXR mode.  I normally use 2.0 with SteamVR, but with this I find that 2.2 is better.

Edited March 30, 2022 by Supmua

[peachmonkey]

20 hours ago, Supmua said:

Ok the final verdict from me, been flying as much as I could whenever I’m home.  If you haven’t tried this with the Aero, you’re missing out…big time.  The ability to use 100% rendering resolution on the Varjo Aero while retaining decent fps just wasn’t possible before until now.  And the visuals are absolutely amazing at this resolution, note that I’m also using Higher mode on the Aero instead of default.  Everything just looks crisp, with next to nothing aliasing artifacts.  Not only that, things are bound to get better once foveated rendering works properly…and dynamic foveated (eye tracking) is also coming soon at least for the MSFS counter part.  Detailed FPS option from the toolkit will display CPU and GPU frametimes, and more for those who like to tinker—so fpsVR is not needed.  Sharpening is possible via NIS/FSR setting even at 100% scaling, it’s not as good as Reshade’s lumasharpen in terms of making things pop, but the overall visuals look more natural (a tad dimmer and less vibrant) rather than artificial.  The gamma is slightly different in OpenXR mode.  I normally use 2.0 with SteamVR, but with this I find that 2.2 is better.

 

There you go! I'm glad you're on board.

OpenXR indeed brings that much needed smooth VR experience in DCS, there's no other way.

[dburne]

On my virgin install of DCS Open Beta, with the Aero , I am getting fps showing in the 60's and the experience seems to be pretty smooth to me. Amazingly smooth considering it does not yet have a working motion smoothing.  Certainly not enough jitters to bother me if any at all. This is flying both high and low. Hornet in a campaign in the Persian Gulf. And Apache training missions in the Caucasus. I really find the experience to be quite good with gorgeous graphics. 

This is why I am so hesitant to try going through all this modding of my install as I just can't visualize it making the experience a lot better for me. I don't know maybe I am crazy but seriously I am quite happy at this time running the Aero with DCS. Maybe I will give it a try at some point just for kicks and grins, but like I say I like having a clean install of DCS with no Mods. I suppose if this mod allowed me to run at higher resolution than default with the same performance then I could see that being enticing. But then I also see all the posts from users doing this seemingly having issue after issue. Then of course one has to keep I guess remove and reinstall it after every DCS update or hotfix. I thoroughly enjoy spending most of my time flying and learning the modules versus tweak after tweak in a never ending search for best visuals with best performance.

So in other words, I am considering trying it but still have great hesitation...

[javelina1]

7 minutes ago, dburne said:

On my virgin install of DCS Open Beta, with the Aero , I am getting fps showing in the 60's and the experience seems to be pretty smooth to me. Amazingly smooth considering it does not yet have a working motion smoothing.  Certainly not enough jitters to bother me if any at all. This is flying both high and low. Hornet in a campaign in the Persian Gulf. And Apache training missions in the Caucasus. I really find the experience to be quite good with gorgeous graphics. 

This is why I am so hesitant to try going through all this modding of my install as I just can't visualize it making the experience a lot better for me. I don't know maybe I am crazy but seriously I am quite happy at this time running the Aero with DCS. Maybe I will give it a try at some point just for kicks and grins, but like I say I like having a clean install of DCS with no Mods. I suppose if this mod allowed me to run at higher resolution than default with the same performance then I could see that being enticing. But then I also see all the posts from users doing this seemingly having issue after issue. Then of course one has to keep I guess remove and reinstall it after every DCS update or hotfix. I thoroughly enjoy spending most of my time flying and learning the modules versus tweak after tweak in a never ending search for best visuals with best performance.

So in other words, I am considering trying it but still have great hesitation...

Hola Don,  do you have sufficient disk space on any of your SSD's?  I know your position about not wanting to mod, (which is cool).   This would be extreme, but you could make a parallel copy of your virgin install.  Then use that 2nd version for testing things out?   Just a thought....