Same as myself and Lomber and MajoCthulhu. It has to be something on the game’s level. In Unity you can check for specific operatingSystems using SystemInfo.operatingSystem() and what not, and I think as long as it reads Steam anything on a hardware level. and you can check if the name contains specific strings and if it does, it sets whatever values you want.
It’s a simple thing to check at an engineering level.
EDIT: Looking at a project of my own, I am using the SteamWorks API, and SteamUtils.IsSteamRunningOnSteamDeck() is a quick boolean that tells whether its on a steam deck, so I think the resolution limits are wrapped in that somehow I betcha. I think its fine to check for deck and use that as a way to gate full screen / windowed operation since on SteamOS and SteamDeck in particular, you’d want it to be limited there. But resolution? I don’t know, it does makes sense however I think it’s too tight a grip in this case.
Also just one other thing to highlight here, on the SteamMachine game properties menu the 2nd option under “General” is a toggle to “Identify to the game as running on a Steam Deck”
I believe this achieves the same thing as the SteamDeck=0 %command% and as you can see it’s disabled.
Having this on or off doesn’t make a difference for me; same thing with the launch option command. Maximum game resolution is set to 4k (global setting) etc. Tried with Proton GE and a few other versions just in case.
Then this option doesn’t work at all I guess, and should be reported as such to Valve.
I actually opened an issue in their github addressing similar concerns, and some interesting workarounds, which you might wanna take look around, and comment on if you have some more information to add.
I hope this gets resolved because according to Valve, Steam Machine should not be treated as a Steam Deck, as this should have been patched with the release of the SM, but unfortunately something did go wrong in the process.
If you want to test the script that I have, you can also ping me on Discord so we can deploy it on the SM as well while waiting for Valve to fix their shit.
