Famed game developer John Carmack has been an instrumental part of the Oculus Rift virtual reality headgear from the start. He helped to popularize the device before Oculus became a company, and before its successful Kickstarter project. The Doom, Quake and Wolfenstein programmer believed in virtual reality so much that he joined Oculus as Chief Technical Officer in August. Now, he's quitting the game company he co-founded twenty-two years ago — id Software — to focus on virtual reality as a full-time project.

According to a statement from id Software (via Polygon), Carmack has resigned from the studio after completing all his current work at the company. "John's work at id Tech 5 and the technology for the current development work at id is complete, and his departure will not affect any current projects," wrote Tim Willits, id Software studio director.

When Carmack first joined Oculus, though, the plan was for him to remain at the game developer as well. What changed? Carmack himself says it "just didn't work out" in a tweet issued today.

I wanted to remain a technical adviser for Id, but it just didn't work out. Probably for the best, as the divided focus was challenging. — John Carmack (@ID_AA_Carmack) November 22, 2013

Willits also writes that Carmack "became interested in focusing on things other than game development at id," but says the studio was fortunate to work with him and wishes him well.

Carmack may have plenty of time to focus on virtual reality now: his other major project, a private rocket-building company by the name of Armadillo Aerospace, was put on indefinite hold a few months ago.