Continuing on with my previous posts about this topic, Carmack actually addressed the state of their varifocal technology in the above talk. I guess the much coveted Half Dome varifocal prototypes they demonstrated (well, "demonstrated" as in "showed a through the lens video of it") still have lots of problems and didn't really work well outside of the lab. Also, problems with cost and glasses. Unsurprisingly varifocal that isn't "perfect" is worse than fixed focus. It seems quite premature to me then that Lanman claimed varifocal was "almost ready for prime time" 1.5 years or so ago. Carmack hopes they can collect a bunch of eyetracking data across wider populations with their next headset (to increase accuracy I suppose), but this seems to confirm varifocal isn't going to be a feature from them any time soon. But just how accurate and robust does eyetracking have to be for this to work in a consumer product? E.g. if eyetracking running at >200hz screws up your focus once every minute, does that create an unacceptable user experience?
https://skarredghost.com/2021/10/22/creal-ar-vr-lightfields
Then there's this demo of CREAL which approximates a light field: "CREAL states that its innovation is in not calculating low-resolution lightfields for many positions, but few high-quality resolution lightfields in a few selected positions around the eye of the user". The impressions are very exciting to me because it sounds like it's another step along the path of addressing the primary issues I have with VR:
However, there's no actual eyetracking and the lightfield portion of the display is limited to a mere 30 degrees (the display is foveated, there's a standard fixed focus display around the perimeter and the transition between the two is abrupt). I have to wonder if it's possible to use a similar kind of display but with eyetracking so the lightfield region follows your eye--sort of similar to what @STiFU mentioned a while back (though that was with a holographic display).