Hacker News Reader

Comment by chx | Hacker News Reader

The fundamental problem with VR is the "VR illusion" which makes the eyes focus on objects apparently in the distance that are actually on a screen very close to the eyes. This gives users headaches thus making mass appeal impossible. Solving this, if it is solvable at all, is challenge #1.

View on HN

Focal distance is dependent on the lenses used. Most VR headsets have a fixed focal distance of 1.3m or 2m. Those interested in the literature can use the keyword "vergence-accomodation conflict" (VAC) for more information on this.

This is a well known problem, and there are quite a few potential solutions - Doug Lanman, the lead of Display Systems Research @ FRL made a bunch of nice presentations on a variety of different approaches a couple years ago (all on YouTube, well worth watching one [1] for anyone with a passing interest in the really cool developments going on).

While I think varifocal is going to be the near-term solution, I do have a soft spot for the various light field displays I've seen.

[1] EI 2020 Plenary: Quality Screen Time: Leveraging Computational Displays for Spatial Computing https://www.youtube.com/watch?v=LQwMAl9bGNY

As I understand it, due to lens setup this shouldn’t actually be the case. Iirc the view for say a Valve Index ends up at something like 60cm.

Here’s some actual problems that are harder:

* while your eyes remain accommodated to focus on that distance, it no longer corresponds with the way they track objects close or far away, by pointing closer together etc

* lack of correspondence between movement on screen and in the real world (usually translation, rather than rotation which tracks head position) for non-roomscale content (i.e. games where you move around larger scenes) causes motion sickness.

Nonetheless, the #1 problem is still not giving users headaches for whatever reason :)

I believe vergence accomodation can still be a problem, even if the focus is fixed at 60cm (close to infinity). If an object is up close in the virtual world (say 20cm), it's still stuck at a focus of 60cm.

I believe Nvidia demoed a solution for this at SIGGRAPH ~4 years back. Liquid lenses were employed to change the lenses focal length based on the content and user gaze.

I got a Quest to try out VR, connected it to the internet and took it off to let updates install, and instantly felt sick as soon as it was off. It lasted all day and I've never put it back on. It was super cool for the 3 minutes I spent connecting to wifi.

That first experience was the same for me, it heavily depends on the game you attempt too play wherever you're able to get used to it or just keep getting KO'd.

If you give it another try I'd suggest games such as SuperHot, beat saber and pistol whip, as youre only controlling your camera perspective, which makes it much more tolerable.

But yeah, one frame drop and it's gonna feel like someone bashed your face in without leaving a bruise. My worst experience had me feeling unwell for several days after, just thinking about putting the headset on gave me a bad feeling.

I feel like this current version of VR is just a proof of concept, but i don't think it's going mainstream for gaming, ever. Controls are clunky at best compared to what you can do on a regular display, as everything else makes you nauseous

Empirically I would say this affects only a small minority of people. Maybe 5-10% at most. It's a barrier to certain types of adoption but not nearly the showstopper you are making out I think.

It depends on what you mean by "affect" (I'd be curious also where you're getting your empirical data from since there's not a lot of publicly published data from what I can find). While I agree it's not necessarily a showstopper, the negative results in the studies I've seen all point to VAC as being something that is a negative factor that is high on the list of things to solve for.

Shibata, Takashi, Joohwan Kim, David M. Hoffman, and Martin S. Banks. “Visual Discomfort with Stereo Displays: Effects of Viewing Distance and Direction of Vergence-Accommodation Conflict.” Proceedings of SPIE 7863 (February 15, 2011): 78630P-1-78630P – 9. https://doi.org/10.1117/12.872347.

Daniel, François, and Zoï Kapoula. “Induced Vergence-Accommodation Conflict Reduces Cognitive Performance in the Stroop Test.” Scientific Reports 9, no. 1 (February 4, 2019): 1247. https://doi.org/10.1038/s41598-018-37778-y.

Batmaz, Anil Ufuk, Mayra Donaji Barrera Machuca, Junwei Sun, and Wolfgang Stuerzlinger. “The Effect of the Vergence-Accommodation Conflict on Virtual Hand Pointing in Immersive Displays.” In Proceedings of the 2022 CHI Conference on Human Factors in Computing Systems, 1–15. CHI ’22. New York, NY, USA: Association for Computing Machinery, 2022. https://doi.org/10.1145/3491102.3502067.

Reply on news.ycombinator.com