The days when VR devices cost as much as a cast-iron bridge and were the destiny of only weird enthusiasts have gone. Today, everyone has heard of virtual reality, and almost everyone can afford a VR helmet.
The Basis of VR: The Screen and Lenses
In essence, VR helmets are as simple as gambling at National Casino. It’s just a screen placed close to the eyes. However, if you take a smartphone and stick it on your nose, there will be no VR effect – you can’t even focus. This is why the most important component of any VR helmet is the lenses, the most common optics. They give the image a usual spherical shape to our eye, help to focus and deceive the brain a bit. The wider the viewing angle lenses provide, the more realistic the image will be perceived. A comfortable minimum today is 110 degrees.
The screens are not so simple either. Response speed, high refresh rate and pixel density are extremely important for virtual reality. And all this needs to be realized on a small panel! This is where VR-device developers have to struggle with physics. For example, OLED screens work well in TV sets, but pixels in such displays are physically far away from each other. So, in VR helmets, OLED screens, even with a very high resolution, create a so-called mosquito net effect. Now new helmets use high-density IPS matrices, and in the future we will increasingly hear about microOLED technology, which can achieve a density of 3,000 dots per inch (now it’s hard to get beyond 600).
Refresh rate and response speed are important parameters to keep the brain from “rejecting” the picture. For example, a refresh rate below 90 Hz for each eye will make most people dull. And to render two images at that rate, you need powerful hardware. So VR is still a pretty resource-hungry thing. But eye tracking (already used in more expensive helmets) can partly help solve this problem, with which you can render the image in detail only in the area of focus – that’s how our eyes work. This is especially useful for standalone helmets with built-in hardware.
Cameras and Other Sensors
It’s not enough to simply feed a realistic image to the eye to create an immersive effect. VR games must track the user’s movements in space, allowing them to walk around the virtual world and look around.
The key technologies for tracking a helmet in space are two: internal and external tracking. They also work well together. External tracking requires external cameras, which will calculate the position of the helmet in space. We call these devices cameras conventionally, because now they rely more on laser sensors. This way of tracking is the most accurate. But the internal one wins in terms of convenience. Its essence is that there are wide-angle cameras mounted directly on the helmet, which track everything. The accuracy of this method is also high, but it’s lower than the external one. There are insurmountable disadvantages: for example, with internal tracking, it’s essential to track the movements of the controllers, if the user will put his hands behind his back.
But although cameras are the basis of head tracking, gyroscopes and accelerometers provide additional assistance. Simply put, the former help track turns more accurately, while the latter help track movements from one point to another. Without these additions, it’s impossible to achieve a tracking speed of 50 milliseconds, and if the value is higher, the brain won’t be fooled and the motion sickness effect will be triggered again.
Controllers for Natural Interaction With Virtual Reality
When the VR industry was very small and experimental, everything in virtual reality was perfectly controlled with an Xbox gamepad. But it quickly became clear that it didn’t give the freedom it needed – so touch, or motion controllers, appeared. They allow you to interact with virtual space in a more natural way – not by twisting the sticks, but by moving your hands and using them to pick up and touch objects.
It’s difficult to praise the sound in VR devices because most of the helmets have the most common headphones. The Quest 2, for example, the most popular and affordable helmet today, works on the principle of emitters – you don’t need to put anything in your ears. It’s convenient, but the sound permeates outward, and the quality itself is, shall we say, average. In-channel or full-size headphones with 7.1 surround sound technology are still perfect. But the manufacturers of most helmets offer buyers to deal with this problem themselves and simply connect their headphones to the helmet.
But augmented reality devices sometimes use bone conduction headphones – they transmit sound via vibration through the jaw bones, bypassing the middle ear. It sounds futuristic, but the technology isn’t suitable for virtual reality: the sound is deafening, and all external noises are picked up with open ears – what kind of immersion is that?
Why We Need VR Helmets
Gaming seems like the most obvious answer. Indeed, the gaming industry is expanding into virtual reality. Many genres, like racing games and shooters, are being rediscovered in VR. And if just 5 years ago, only small indie studios were working with the technology, today giants like Sony and Ubisoft are creating games for VR.
But the main areas of application of VR are education, medicine and industry. With the help of VR simulators, firefighters, collectors, pilots, and surgeons are now being trained for service. Even basic devices can create such a level of immersion that with the right software a person can get practical skills in specific areas, without putting anyone in danger.