Also found this explanation
Ralf wrote:
There is however an explanation why some may experience an existing user profile as (partially) 3D. The first version of vorpX’s OpenGL render path used alternate frame rendering, which means the left and right eye are rendered at different points in time: left at frame 1, right at frame 2, left at frame 3, right at frame 4, and so on. Given these circumstances moving sideways (strafing) happens to have a similar effect as rendering two images for stereo 3D although vorpX doesn’t create any stereo 3D at all. Moving forward/backward doesn’t produce correct stereo 3D, but apparently some still experience what they see as 3D. My personal guess is that maybe their brains somehow try to make sense of the (garbage) input. I’d consider it way more likely though that you will experience anything else than strafing as weird and unpleasent, so try at your own risk.
Has G3d ever worked in DOOM 2016? Cause it certainty doesnt any more.