OpenVR fholger VR Perf Kit (FSR)

Hardware & Tech Questions
181

Thanks for asking!

I don’t use the VR Performance Kit, just OpenComposite to use OpenXR instead of SteamVR.

I am currently appending “.backup” to the name of D3DCompiler_47.dll (underscore might be in a different place) in DCS/bin folder after every DCS Update. This is necessary to force DCS to use the version of the lib supplied by OpenComposite.

If your app could somehow help me automate this, that would be perfect. Even just an input field for a PowerShell or .bat script to run automatically after every update would suffice.

Is your app open source? I could have a look at adding it myself if you’d like

182

unfortunately not open source, and I’m in the middle of a massive re-write and UI shift,

so I figured while I’m doing that, I saw a bunch of users on reddit and what not asking about it,

Mainly looking into the launch function, to make sure DCS Launches with OXR instead of SteamVR etc.

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183

I use this tool for that. It has a UI too, where you can set which games should use SteamVR and which should use OpenXR, as well as a global default

Only problem is that last time I checked, I still needed to rename that DLL in DCS/bin

184

This is a key point I missed initially. But, on topic (even though I don’t use @SkateZilla 's app) a one-click thingy to fix all this up after each update might be nice.

185

I just renamed the openxr_api.dll and copied the new one from the “per game” install of open composite… And added —force_steam_vr to the dcs.exe.

Different requirements for different VR headsets?

186

Hi Skate…I am an oculus user, and to use OpenXR we need to launch DCS with steamvr (which in reality we don’t use as the call is “taken” from opencomposite). And I am not able to setup your app with it…I try to point the app to the OpenComposite executable but steamvr is kept grayed out.

image

187

I was told oculus users dont see any benefits from OpenXr,

Only Windows MR → SteamVR Users as the multiple APIs cause performance degradation.

I likely will add an OpenXR option to that drop down menu, which will launch DCS with the same variable as steamVR.

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188

Varjo Aero users see quite an improvement too. But I think that’s mostly because DCS now sees all Varjo headsets as the four screen-in-screen versions and starts churning out four video streams, instead of two. Happened a couple of updates ago. Anyway, installing the openxr_api.dll from open composite and adding —force_steam_vr to dcs.exe cured everything.

189

will the force-steam variable still work if SteamVR isnt installed though? or will it launch and just resort to previous API if not detected.

190

Not sure… If you have a Varjo headset, DCS will not launch with the SteamVR API, which is required for the opencomposite dll to work.

Edit. The force steamvr variable doesn’t actually launch SteamVR as this call is intercepted by opencomposite to render in OpenXR instead.

191

i will look into integrating the search for the xr exe and launching with steamvr variable, and see how it goes.

192

That’s two dashes, right, as in: --force_steam_vr?
I have no command line arg, adding the above seems to make no difference, at least in performance (I like it [OpenXR] for all the other gadgets).

Anyway, thanks

193

Yes, and one space after exe, like this:
“dcs.exe” --force_steam_vr

Note that the regular way of starting DCS is via the updater, so you must make a new shortcut that goes directly to dcs.exe.
You also need the openxr_api.dll from opencomposite.
https://znix.xyz/OpenComposite/download.php?arch=x64
Put it in the bin folder of DCS (perhaps renaming the existing one if you want to switch).

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195

we see less benefits, but with openxr we can use openxr toolkit and so use NIS/FSR and Fixed Foveted Rendering which still helps with performances