ALVR VS OpenHMD

https://github.com/alvr-org/alvr

They also achieve very low latency, I didn't follow every single optimization they added but it basically boils down to a few encoding tricks (better image in the center, accept blurriness in the peripheral vision), good network infrastructure, and hardware decoding / encoding being really fast.

To use steamvr on flatpak I used this tutorial . There was a disclaimer that nvidia GPUs are not supported, but the guy that suggested it has a 3090, so it might work for me too.

They have a Wiki page on GitHub with a settings tutorial and troubleshooting. A downside with a lot of open-source software is that it's relatively difficult to setup but it might fix some of your issues.

You can play wirelessly using Air Link, Virtual Desktop, or ALVR.

They also have a detailed wiki page on GitHub

https://github.com/alvr-org/ALVR/wiki/Settings-guide Goes in-depth about a lot of the features/settings

Quest 2 needs some workarounds (dev mode account), but once you've done those you can just install ALVR (I recommend nightly). As for the games, check ProtonDB. Some VR games (Pavlov beta, for example) have EAC that blocks proton. Some VR games don't work with ALVR due to https://github.com/alvr-org/ALVR/issues/1392, like the Pavlov beta and Crawlspace. Just install the proprietary NVIDIA drivers and use Xorg and most things should work fine. Steam has Proton, which lets you play Windows games with high performance.

I modified the AUR package for openhmd to build your repo/branch instead. git+https://github.com/thaytan/OpenHMD.git#branch=rift-kalman-filter But the tracking is just as jittery as before and it's still just 3DOF. Is there any special compiler flags or something that need to be activated for 6DOF to work, or is it more likely that I just installed it wrong somehow?

Yes. Was developed by the same guy, in fact: https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter

if they wanna stay with Oculus, they could give the CV1 a try, assuming they know how to setup the drivers for it to work on Linux. Thaytan on github has been working on and improving 6DOF tracking for the CV1 for a while now but is needing help with the tracking part of it to fix a few kinks. You can easily okay Beat Saber with it no problem. Should give it a look if you are interested. Thaytan has some youtube videos as well of some gameplay with it. The branch on github you would want to use is the rift-correspondence-search one. https://github.com/thaytan/OpenHMD/tree/rift-correspondence-search

Oculus Rift DK2/CV1: Try my positional tracking branches of OpenHMD (https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter and https://noraisin.net/diary/?page_id=1048)

Slightly out of date tutorial: https://noraisin.net/diary/?page_id=1048 Github repo for the experimental support: https://github.com/thaytan/OpenHMD

I re-measured distortion parameters on my CV1 last month (https://github.com/thaytan/OpenHMD/commit/46d164a9) and they made things much clearer for me... maybe those parameters aren't right for your headset? Unfortunately it's a really hard thing to get a photo of for me to tell what you're seeing on your end.

OpenHMD Rift Kalman Filter: https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter

https://github.com/ChristophHaag/SteamVR-OpenHMD with https://github.com/thaytan/OpenHMD/tree/rift-kalman-filter would work for now getting the CV1 working positionally tracked on Linux (currently in branch, still experimental but usable!) There are step by step install instructions on https://noraisin.net/diary/?p=1033