Moving away from Reverb G2 - Is SteamVR required?

[Hoggorm]

Hello,

I've been using the HP Reverb G2 until last summer. Since then I've been away from DCS basically so there might be some changes I'm unaware of.

I'm trying out a new headset where I follow this procedure to fly DCS:

First I added DCS as a Non-Steam Game to Steam (Since I own the standalone version only)

Start VIVE Hub
Start SteamVR
From within SteamVR - Start DCS.

Now I was wondering if the start of SteamVR is really necessary?
The headset should support OpenXR, but I really do not know how to proceed.

Is there a way to skip SteamVR or is it as necessary as Windows Mixed Reality was for the Reverb G2?

[Tensorial_Architect]

I don't have a Vive headset to specifically test but I believe that Vive Hub does support OpenXR. This means you do not need SteamVR. When you fire up DCS, you can select to run it in OpenXR mode (which DCS supports natively) without SteamVR.

[Hoggorm]

23 minutes ago, Tensorial_Architect said:

I believe that Vive Hub does support OpenXR. This means you do not need SteamVR.

I believe you are right. It might need to be set up though, so I'm checking that.

24 minutes ago, Tensorial_Architect said:

When you fire up DCS, you can select to run it in OpenXR mode (which DCS supports natively) without SteamVR.

Is that by using the  --force_enable_VR --force_OpenXR command on the DCS.exe file? Or is there an easier way?

[Tensorial_Architect]

I don't believe that is required any longer. A DCS simmer used to have to enter specific commands to get the multi-threading or OpenXR versions to run. For many months now, that is no longer necessary. When I fire up DCS, I have three options to launch the sim under, ... the middle one is to run DCS using its (now) native OpenXR runtime.

[Hoggorm]

3 minutes ago, Tensorial_Architect said:

When I fire up DCS, I have three options to launch the sim under, ... the middle one is to run DCS using its (now) native OpenXR runtime.

I see. I only have two... Desktop and VR mode. And nothing about OpenXR.

[mbucchia]

You are all misunderstanding what OpenXR is/means. 

OpenXR doesn't mean "without SteamVR", and there are many headsets out there that only support OpenXR through SteamVR. Examples: Valve Index, HTC Vive (almost all of them), Bigscreen Beyond... on these headsets, you cannot run 99% of the applications outside of SteamVR.

You haven't specified which HTC Vive headset you are using, however there is a very high chance it only supports OpenXR through SteamVR. The only 2 HTC headsets supported by HTC's "non-SteamVR OpenXR runtime" (sometimes called "native OpenXR runtime"  though it's actually terribly misleading vocabulary) are the HTC Vive Cosmos (non-Elite) and HTC Vive Focus 3 to my knowledge.

Edit: I remembered there is one more scenario, I believe you can use the HTC Vive Elite XR with Virtual Desktop, in which case you can use VDXR (Virtual Desktop's non-SteamVR OpenXR implementation).

Edited February 24 by mbucchia

[Hoggorm]

51 minutes ago, mbucchia said:

You are all misunderstanding what OpenXR is/means. 

For my part I would extend it to say that I have really no idea what OpenXR is... If you have a simple explanation I'd be happy to hear it.

52 minutes ago, mbucchia said:

You haven't specified which HTC Vive headset you are using

This is regarding the Vive Focus Vision headset.

[Tensorial_Architect]

4 hours ago, mbucchia said:

You are all misunderstanding what OpenXR is/means. 

OpenXR doesn't mean "without SteamVR", and there are many headsets out there that only support OpenXR through SteamVR. Examples: Valve Index, HTC Vive (almost all of them), Bigscreen Beyond... on these headsets, you cannot run 99% of the applications outside of SteamVR.

You haven't specified which HTC Vive headset you are using, however there is a very high chance it only supports OpenXR through SteamVR. The only 2 HTC headsets supported by HTC's "non-SteamVR OpenXR runtime" (sometimes called "native OpenXR runtime"  though it's actually terribly misleading vocabulary) are the HTC Vive Cosmos (non-Elite) and HTC Vive Focus 3 to my knowledge.

Edit: I remembered there is one more scenario, I believe you can use the HTC Vive Elite XR with Virtual Desktop, in which case you can use VDXR (Virtual Desktop's non-SteamVR OpenXR implementation).

For some reason, my lizard-like hippocampus recalled the HTC Vive Cosmos (non-Elite) that we once had in our lab and which worked fine without SteamVR as representing most of the HTC headsets. Sadly, have not had an HTC headset in our labs in the last few years. Thanks for the memory recall and clarification!

[Tensorial_Architect]

Hoggorm, you asked, "For my part I would extend it to say that I have really no idea what OpenXR is... If you have a simple explanation I'd be happy to hear it."

OpenXR is an API, ... an application programming interface, ... computer code, .... that various hardware (Meta (Oculus), Varjo, HTC, Pimax, etc ... ) or software (Steam, DCS, specific games) vendors can implement to send and receive a set of commands to a VR headset. It acts as a bridge between the application (DCS, Steam, etc ...) and the VR headset to translate the application's requests into commands (rendering visuals, tracking movement, processing input from hand controllers, etc ...)  that the headset can use. OpenXR is also an "open" standard developed by the Kronos Group (software developers) which means developers and software engineers (like Eagle Dynamics (DCS), Steam, Meta, Varjo, Pimax, MBucchia, etc .... ) don't need to pay fees to anyone to use it. The main benefit of OpenXR is that it allows a software engineer to write code only one time and deploy it across multiple platforms such as Meta Quest, SteamVR, Windows Mixed Reality, etc ... This means that a guy like MBucchia who is trying to help DCS simmers get better framerates for a given graphics card's processing power by rendering only the area where a human eye's fovea is pointed (the area outside where the fovea is pointed is rendered but with less detail (resolution)) can write code only once, instead of needing to write completely different code for every separate VR headset model.

Hoggorm (that sounds for some reason like the name of a Klingon or a dwarf from Middle Earth), you should be using MBucchia's Quad Views/Fixed Foveated software to increase the framerate for your HTC headset. You can find an overview and the links here:

https://github.com/mbucchia/Quad-Views-Foveated/wiki

Edited February 24 by Tensorial_Architect

[Hoggorm]

13 hours ago, Tensorial_Architect said:

you should be using MBucchia's Quad Views/Fixed Foveated software to increase the framerate for your HTC headset. You can find an overview and the links here:

https://github.com/mbucchia/Quad-Views-Foveated/wiki

Thank you!

I'll take a look at that. I find VR difficult to adjust. It seems like I need to adjust VIVE Hub, SteamVR and DCS settings at the same time and all have to match correctly or else... Am I correct?

I struggle with the fact that the image is not clear enough. The framerate is fine (i'd say), but the image looks "foggy", unclear. Like looking through the bottom of a glass bottle... (It is not THAT bad really, it's just a figure of speech )

I've tried to watch several tutorial videos on YouTube, but they all seem to favor performance over quality.

I'll take a look at MBucchias software next week. What I "fear" however with such 3rd party software is that, as mentioned, I already have three softwares that needs adjustments. I fear introducing yet another makes the process even more complicated. And for every software that needs adjustment the possibilities multiplies exponentially... For those that know what they do I guess it's fine, but for me... Oh my...

 

Hoggorm, by the way, is the Norwegian word for a Viper. The only venomous snake we have

[Phantom711]

Am 25.2.2025 um 12:29 schrieb Hoggorm:

VIVE Hub, SteamVR and DCS settings at the same time and all have to match correctly or else... Am I correct?

Well…yes and no. For the most part you can leave the VR settings in DCS alone. Set the pixel density to 1.0 and rather set the resolution either in SteamVR or (I guess) in that VIVE Hub.  
What resolution did you set so far? 

Maybe send us a screenshot of your VIVE Hub and StreamVR settings.

And I kind of agree…leave QVFR out of the equation for now until you are almost happy with your setup.

 

[Hoggorm]

15 hours ago, Phantom711 said:

What resolution did you set so far? 

Maybe send us a screenshot of your VIVE Hub and StreamVR settings.

 

Hello Phantom711,

These are the current VIVE Hub settings:

Setting "Streaming graphics preference" to something like Performance (instead of Ultra) gives, for me, a very bad, blurry, picture. Selecting Ultra gave a huge improvement in visuals but also a heavy framerate drop.

For the SteamVR settings I am unable to provide a screenshot now as I am at work and away for the next week. I can remotely access the computer, but the relevant settings will not show up since the headset is off. If I recall correctly however the only setting I've been playing with was the "Resolution per eye". I had it at 150% before I ended my testings.

Together with the VIVE hub settings this gave a nice clean picture, but unfortunately a too big hit on framerate...

With Performance in VIVE hub and 100% resolution per eye I had 90 fps steady

With Ultra and 150% I had just 25...

[Phantom711]

vor 8 Stunden schrieb Hoggorm:

With Performance in VIVE hub and 100% resolution per eye I had 90 fps steady

With Ultra and 150% I had just 25...

That‘s all a bit borderline…

Since we don‘t know what the respective resolutions are behind the „Performance-Ultra“ terms in VIVE Hub, I would advise to leave SteamVR at 100% and play around with the VIVE settings first. 
I would assume, that „Ultra“ in the VIVE settings is probably also somewhere around 150%. So if you set SteamVR to 150% also, that‘s a whopping 225% supersampling. Not surprised that you end up with 25 FPS.

[Hoggorm]

I got you Phantom711,

Thank you for that good advice! I'll start with VIVE hub when I get back home.