According to Standford and NVidia researchers, VR adoption is slowed by the bulky headsets required. They want to offer a slim solution. A SIGGRAPH paper earlier this year lays out their plan or you can watch the video below. There’s also a second video, also below, covers some technical questions and answers.
The traditional headset has a display right in front of your eyes. Special lenses can make them skinnier, but this new method provides displays that can be a few millimeters thick. The technology seems pretty intense and appears to create a hologram at different apparent places using a laser, a geometric phase lens, and a pupil-replicating waveguide.
A short while ago, Tested posted a video all about hands-on time with virtual reality (VR) headset prototypes from Meta (which is to say, Facebook) and there are some genuinely interesting bits in there. The video itself is over an hour long, but if you’re primarily interested in the technical angles and why they matter for VR, read on because we’ll highlight each of the main points of research.
As absurd as it may seem to many of us to have a social network spearheading meaningful VR development, one can’t say they aren’t taking it seriously. It’s also refreshing to see each of the prototypes get showcased by a researcher who is clearly thrilled to talk about their work. The big dream is to figure out what it takes to pass the “visual Turing test”, which means delivering visuals that are on par with that of a physical reality. Some of these critical elements may come as a bit of a surprise, because they go in directions beyond resolution and field-of-view.
Solid-state varifocal lens demo, capable of 32 discrete focal steps.
At 9:35 in on the video, [Douglas Lanman] shows [Norman Chan] how important variable focus is to delivering a good visual experience, followed by a walk-through of all the different prototypes they have used to get that done. Currently, VR headsets display visuals at only one focal plane, but that means that — among other things — bringing a virtual object close to one’s eyes gets blurry. (Incidentally, older people don’t find that part very strange because it is a common side effect of aging.)
The solution is to change focus based on where the user is looking, and [Douglas] shows off 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 composed of stacked elements that can selectively converge or diverge light based on its polarization. [Doug]’s pride and excitement is palpable, and he really goes into detail on everything.
At the 30:21 mark, [Yang Zhao] explains the importance of higher resolution displays, and talks about lenses and optics as well. Interestingly, the ultra-clear text rendering made possible by a high-resolution display isn’t what ended up capturing [Norman]’s attention the most. When high resolution was combined with variable focus, it was the textures on cushions, the vividness of wall art, and the patterns on walls that [Norman] found he just couldn’t stop exploring.
An old adage says out of cheap, fast, and good, choose two. So if you’re like [Philip Moss] and trying to make a comedy series on a limited budget rapidly, you will have to take some shortcuts to have it still be good. One shortcut [Philip] took was to do away with the set and make it all virtual.
If you’ve heard about the production of a certain western-style space cowboy that uses a virtual set, you probably know what [Philip] did. But for those who haven’t been following, the idea is to have a massive LED wall and tracking of where the camera is. By creating a 3d set, you can render that to the LED wall so that the perspective is correct to the camera. While a giant LED wall was a little out of budget for [Philip], good old green screen fabric wasn’t. The idea was to set up a large green screen backdrop, put some props in, get some assets online, and film the different shots needed. The camera keeps track of where in the virtual room it is, so things like calculating perspective are easy. They also had large arUco tags to help unreal know where objects are. You can put a wall right where the actors think there’s a wall or a table exactly where you put a table covered in green cloth.
Initially, the camera was tracked using a Vive tracker and LiveLink though the tracking wasn’t smooth enough while moving to be used outside of static shots. However, this wasn’t a huge setback as they could move the camera, start a new shot, and not have to change the set in Unreal or fiddle with compositing. Later on, they switched to a RealSense camera instead of the Vive and found it much smoother, though it did tend to drift.
The end result called ‘Age of Outrage’, was pretty darn good. Sure, it’s not perfect, but it doesn’t jump out and scream “rendered set!” the way CGI tv shows in the 90’s did. Not too shabby considering the hardware/software used to create it!
The Oculus brand VR headset and other similar devices allow you to view 3D worlds, but they can be blurry and unsatisfying if you’re a glasses wearer. Alternatively, you might be able to see fine, but find your glasses get in the way of a comfortable experience. Either way, you might want to integrate prescription lenses into your headset, and thankfully, there’s a straightforward way to do so thanks to [tanvach].
The way to do so is by using these 3D-printed lens adaptors. They take standard single vision lenses as designed for the Zenni #550021 round glasses frames, and let them fit nicely inside a Oculus Quest, Quest 2, or Rift S headset. [tanvach] supplies instructions on how to order the lenses for your own prescription, and notes that the key is to get the antireflective coating to reduce glare. And, if you don’t want to print your own adapters, you can source some pre-printed instead!
The adapters are a great way to improve your VR experience if you’re someone that typically relies on corrective lenses. Of course, it’s getting more popular to simply DIY your own headset these days, too. If you’ve got your own neat VR project in the works, don’t hesitate to let us know!
At one point or another, we’ve probably all wished we had a VR headset that would allow us to fly around our designs. While not quite the same, thing, [manahiyo831] has something that might even be better: a VR spectrum analyzer. You can get an idea of what it looks like in the video below, although that is actually from an earlier version.
The video shows a remote PC using an RTL dongle to pick up signals. The newer version runs on the Quest 2 headset, so you can simply attach the dongle to the headset. Sure, you’d look like a space cadet with this on, but — honestly — if you are willing to be seen in the headset, it isn’t that much more hardware.
What we’d really like to see, though, is a directional antenna so you could see the signals in the direction you were looking. Now that would be something. As it is, this is undeniably cool, but we aren’t sure what its real utility is.
What other VR test gear would you like to see? A Tron-like logic analyzer? A function generator that lets you draw waveforms in the air? A headset oscilloscope? Or maybe just a giant workbench in VR?
[Lucas VRTech] has made some significant progress with building force-feedback type haptic gloves for use with Steam VR games. The idea is pretty straightforward: the end of the finger is attached to a cable, which is pulled from inside a sprung-loaded spool; the kind used for hanging ID cards on.
The spool body can rotate, but a peg protruding from it engages with the arm of a co-located servo motor. This produces a programmable stop position. But it is a hard stop, and it is not possible with the current hardware to detect precisely when the stop is reached, nor is it possible to control the force it is pushing with. Such features are not difficult to achieve, its just a matter of a little more development with some custom mechatronics.
The current prototype has a focus on cost, which is great as an early development platform. By leveraging 3D printing and off-the-shelf parts that are easy to source; just a handful (chuckle!) of potentiometers, some servo motors and one from any number of ESP32 dev boards and you’re done. The real work is on the software side of things, as the games themselves need to be modified to play ball with the VR glove hardware. This has been achieved with a combination of a custom steam driver they call OpenGloves, and community developed per-game mods. A few titles are available to test right now, so this is definitely something some of us could build in a weekend and get involved with.
The hardware source for the glove mount and per-finger units can be found on the project GitHub, together with the ESP32 source for Arduino.
[Rob Cole] had an ambitious side project: to build an improved version of the Valve Index VR controllers. His effort, named Project Caliper, aims for optimal ergonomics and modularity for the handheld devices. [Rob] originally had plans to develop it as a consumer product by forming a small startup company, but after taking a hard look at the realities of manufacturing delays, semiconductor shortages, and the high costs of developing hardware, decided that the idea just didn’t seem justified at the time.
An XRCaliper prototype
However, the project was still to take shape. [Rob] is a self-learner, and highly passionate about the value of human-centric design. He started by building a basic controller that could be tracked in SteamVR, then a lot of work prototyping the finer points of controller design, and finally moving on to developing Project Caliper, his concept for a fully-adjustable, modular VR controller. The article he’s written takes you on a journey through the development of the project, and it is chock-full of prototype pictures for those of you who want to see just how much work can go into developing the actual physical realities of a handheld device. Some of his discoveries are pretty interesting; for example, he put a small vibration motor on a dorsal strap of one of his prototypes, thinking it would be a good place for feedback since the back of the hand is quite sensitive. It turned out that vibration applied to the back of the hand was powerfully felt as though it were inside the hand.
While its future as a consumer product isn’t certain, [Rob] is still working on the Project Caliper design and shares progress and photos on Twitter. Developing VR hardware isn’t easy, but at least there’s a much more robust framework for it nowadays, and thankfully no longer any need to roll your own tracking from scratch.
