SteamVR/Desktop Game Theater
The SteamVR Desktop Game Theater is the component of SteamVR responsible for displaying traditional desktop games, as well as media files like movies, in virtual reality for SteamVR.
The SteamVR Desktop Game Theater executable can be found in "C:\Program Files (x86)\Steam\SteamApps\common\SteamVR\tools\steamvr_desktop_game_theater\win64\steamvr_desktop_game_theater.exe" (assuming a default Steam install).
Command line arguments taken by steamvr_desktop_game_theater.exe
-legacygame [name]: A string (
[name]) for the name of the game being launched, eg.
"Team Fortress 2". It's not exactly clear where or how this parameter is used.
-overlaykey "valve.steam.desktopgame.[appid]": The app to launch in the Steam Overlay, where
[appid]is the game's Steam Application ID. Other kinds of application may be acceptable with a different prefix (non-Steam games?)
-pid [pid]: The PID (
[pid]) of the Steam Client Bootstrapper (Steam.exe) process that is responsible for the theater.