
That is until Marulu developed a technique to send frames directly to the new VR APIs a hack which he teases was actually developed for another “secret project” that hasn’t yet been announced. That meant that official VR support in Source-based games like Half-Life 2 never made the jump to the consumer Vive and Rift headsets. “Oculus and SteamVR both need DirectX 10+. Valve thus abandoned and left it in the DK2 ‘extended’ state based on a old SteamVR version.”

“The Source engine is DirectX 9 only which does not allow texture sharing and is not supported by any of the new VR APIs ,” Marulu told me.

Two of the new members-who go by pseudonyms Marulu and Street Rat-are responsible for developing a key hack that would make it possible to bring Half-Life 2 to modern VR headsets. Speaking to the team behind the Half-Life 2: VR mod, we learned more about the technical issues which halted development of the original mod several years back.
