Not long ago, Tested posted a video about hands-on time with Meta’s (i.e. Facebook) virtual reality (VR) headset prototypes and there’s some really cool stuff in there. The video itself is over an hour long, but if you’re primarily interested in technical angles and why they matter for VR, read on as we’ll highlight each of the main research points.
As absurd as it may seem to many of us to have a social network spearheading significant VR development, it can’t be said that they don’t take it seriously. It’s also refreshing to see each of the prototypes presented by a researcher who is clearly excited to talk about their work. The big dream is to figure out what it takes to pass the “visual Turing test”, which means providing visuals on par with those of a physical reality. Some of these critical elements may come as a bit of a surprise, as they go beyond resolution and field of view.
At 9:35 p.m. on the video, [Douglas Lanman] shows [Norman Chan] what is the importance variable focus is to provide a good visual experience, followed by a walkthrough of all the different prototypes they used to achieve this. Currently, VR headsets display visuals on a single focal plane, but that means, among other things, that bringing a virtual object closer to your eyes becomes blurry. (Incidentally, older people don’t find this part very odd because it’s a common side effect of aging.)
The solution is to change focus based on where the user is looking, and [Douglas] shows all the different ways this has been explored: from motors and actuators that mechanically change the focal length of the display, to a solid-state solution made up of stacked elements that can selectively converge or diverge light depending on its polarization. [Doug]The pride and excitement of is palpable, and he really goes into great detail about everything.
At 30:21, [Yang Zhao] explains the importance of high resolution displays and also talks about lenses and optics. Interestingly, the super-clear text rendering made possible by a high-resolution display isn’t what ended up capturing [Norman]is the most attention. When high resolution was combined with variable focus, it was the textures of the cushions, the vividness of the wall art and the patterns on the walls that [Norman] discovered he just couldn’t stop exploring.
The next step at 39:40 is something really interesting, illustrated by [Phillip Guan]. A VR headset has to apply software corrections for distortions, and it turns out those fixes can be complex. Not only does an image experience some distortion as it passes through a lens, but that distortion changes in nature depending on where you look. This all has to be fixed in software for a high fidelity experience, but a real bottleneck is having to wait for a physical prototype to be built, and what complicates this is that different people will have subjective experiences of slightly different distortion. To remedy this, [Phillip] shows a device whose purpose is to accurately simulate different physical helmet designs (including different purposes and users) in software, allowing exploration of different designs without having to build anything.
The final prototype – named Starburst for reasons that will soon become clear – is shown at 44:30 and demonstrates the power of true high dynamic range. This is the most unwieldy aspect, but that’s mostly down to essentially having car headlights as your backlight. The goal is not to blind users, but to provide something important and missing. Why is high brightness so important? The answer is simple: real-world light levels are far beyond anything a modern monitor (or VR headset) can offer. This means that in virtual reality, a projector really only looks like a image of a projector. It will never really look like bright, not the way your eyes and brain actually sense the word. When headsets can deliver a true HDR experience, that will change, and that’s what this prototype delivers.
Clearly, this direction is taken very seriously, and it may come as a surprise to learn that delivering a compelling viewing experience goes far beyond higher resolution and a wider field of view. All of the really great VR ideas may have been dreamed up in the 1960s, but this video is a great showcase of what goes into the painstaking scientific work of figuring out how to solve a problem.