[BUG] Distortion in Right Eye on Index in Dashboard While Game Runs

[RookiePrime]

Description
When running Until You Fall, Light Brigade, Half-Life: Alyx, or Puzzling Places on my Valve Index and pressing the system button (on headset or controller) to open the SteamVR dashboard, right eye image distorts, like it's being pulled up and to the right while the bottom left corner is anchored.

To Reproduce
Steps to reproduce the behavior:

1. Launch SteamVR.
2. Launch any of the above titles (and probably others, these four are just the four I tried).
3. Press system button on either controller or the headset.
4. Right eye is distorted until I press the system button on either controller or the headset, or exit the game.

Expected behavior
When I open the SteamVR dashboard, both eyes see an undistorted view of the dashboard and the underlying game in process.

System Information:

• Steam client version: 1775946595
• SteamVR version: 2.15 (stable)
• Distribution: Bazzite (bazzite-nvidia-open with KDE)
• Steam runtime diagnostics: Steam Runtime System Information.tar.gz
• Steam and SteamVR logs: steam-logs.tar.gz
• Minidumps: steam-minidumps.tar.gz

Screenshots
Would love to be able to give screenshots of this, but the distortion doesn't appear in the SteamVR display view. If someone knows how to capture the raw image going to the headset, let me know!

Additional context
This does not happen on my Quest 3. Don't know if it happens (or not) on latest SteamVR beta, because everything instead crashes on the latest beta!

[Packetdancer]

When you say it doesn't happen on the Quest 3, I assume you're using VRLink to connect to it?

Either way, that sounds like an issue in the driver. You mention it happens on certain games -- does it NOT happen on other games? (Because if so, having one that doesn't show the issue is useful to compare to.)

[RookiePrime]

Yep, using Quest 3 via VRLink for this.

I haven't found any game it doesn't happen on, at least not yet. I just installed and booted Midnight Walk, Beat Saber, Superhot, and Pistol Whip to check in those. All of those, same issue.

Minor correction of description of distortion, since I'm getting a lot of time to really look at it: it's as though the bottom left corner of the right eye image is anchored but the top right corner is being pulled to the right, stretching the image.

[Packetdancer]

...ah, my nemesis returns for revenge in a new form. Wonderful. 🙃

I definitely don't see it in Superhot VR or Beat Saber; both of those are in the set of apps I cycle through for testing (along with Space Pirate Trainer, BeamNG.drive's native Linux build, etc.)

Given that I'm not seeing it myself here -- to confirm, this ONLY happens when you pull up the dashboard? E.g., the game is fine without the dashboard, but goes wacky as soon as its up?

[RookiePrime]

Ha, I was just picking whatever titles could install quickly, didn't mean to open up old wounds!

And yup, it only happens with the dash open, and it ends when the dash closes. Me manually opening the dash isn't important, I don't think, because there's usually an instant when I launch a game where the distortion occurs for a moment before SteamVR closes the dashboard automatically (and the distortion ends with it). But otherwise, if I just play the game without opening the dash, it's decidedly unwacky.

[Packetdancer]

Oh, no, it's more that the stretchy distortion is somewhat similar to the Walkabout Mini Golf issue, which is very squirrely and does not want me to find it. :P

Alright -- given the only-with-dashboard aspect, it sounds very similar to #866 -- I'm not convinced it's the same issue (due to vrlink being involved here), but it's worth keeping an eye on both.

[Packetdancer]

Huzzah, I now have a Linux test box that can reproduce this issue.

[RookiePrime]

Hurray! I gotta admit, sometimes I wonder when I run into issues if it's just Bazzite, or somehow something I did. Has me thinking I should hop over to another one with a fresh install. But I'm glad to hear it's reproducible!

[Packetdancer]

Okay, so... I can reproduce this on the Index on Bazzite (provided that async is disabled) a'la #866, but I cannot reproduce it on Quest 3 (or Frame, or really anything using VRLink).

If you're seeing it on VRLink, can you let me know what settings you're using? (Refresh, render resolution, etc.) Because if it has a shared cause with #866, managing to find where it triggers on VRLink will help track it down.

[RookiePrime]

Oh, it doesn't happen on Quest 3 for me at all. Just on Index.

[Packetdancer]

Okay, good. Not losing my mind, then. :)

[Packetdancer]

Okay, so what I've reproduced and found is not quite the same thing you describe, but given how you describe it only happening when the system layer is up, I am fairly sure it has the same root cause. Especially since your logs do show async mode being disabled.

In the interests of some sanity-checking, can you set enableLinuxVulkanAsync to true in your steamvr.vrsettings? (You can look for "async" in vrcompositor.txt to make sure it's enabled.)

[RookiePrime]

Well look at that, enableLinuxVulkanAsync fixes this particular problem! Introduces a new problem to the bottom third of my vision, in which it sorta moves fractionally slower than the rest of my vision, I think? Reminds me of the wobbly distortion correction that camera passthrough has on Quest. But the right eye distortion, when the dash is open in a game, is gone with that setting enabled.

Edit: Two addendums, one directly related and one tangential. Directly related, I notice that the SteamVR dash appears to operate at a lower framerate with async enabled. Tangentially, I switched back to beta branch and booted up... and games don't instantly crash on my Index like they were, when async was disabled. Same wobbly bottom-third vision and choppy dash, though.

[Packetdancer]

Okay, cool. That result actually tracks with what I'd expect, which means that yes, this does indeed have the same underlying issue despite the slightly-different presentation.