I've gone ahead and uploaded the court documents filed in Texas today, if you wish to peruse the 46-page complaint.
The complaint outlines, from ZeniMax's perspective, the timeline of Oculus Rift's transition from hobby project to Facebook sale. It alleges the device could not have become a transformative technology without the work contributed by John Carmack and other employees at ZeniMax while all were employed at ZeniMax.
ZeniMax alleges Oculus founder Palmer Luckey had ongoing contact with Carmack and other ZeniMax employees ahead of the successful Kickstarter project and long after, and the technical knowhow provided to Luckey was instrumental in the Oculus Rift's development.
Carmack, a longtime VR evangelist, reportedly first discovered the Oculus Rift through an online forum, and received a prototype as early as April 2012, several months before the Kickstarter.
Much of the complaint focuses on the relationship between Carmack and Luckey, specifically highlighting the many times in which the two of them publicly acknowledged the contributions of one another to the Oculus Rift long ahead of Carmack actually joining the company.
Oculus responded to today's lawsuit with a brief statement.
"The lawsuit filed by ZeniMax has no merit whatsoever," the company said. "As we have previously said, ZeniMax did not contribute to any Oculus technology. Oculus will defend these claims vigorously."