Explained: How does VR actually work?
How does VR work? How does a virtual reality headset make you think that you're sitting in a spaceship in a distant galaxy when you are, in fact, actually about to bump into the kitchen counter? Well, with the army of VR devices expanding, we'll be explaining how they actually work.
While devices generally take the same form, how they project imaging in front of our eyes varies greatly. The likes of the HTC Vive and Oculus Rift provide PC-based operations, though major players such as Google and Samsung offer more affordable, smartphone-based headsets. Sony has also managed to crack the console scene with its Playstation VR.
Standalone VR is something you'll be hearing more of too - in 2018 Oculus will launch the Oculus Go, and Lenovo's standalone Daydream headset is also expected.
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Once your headset and power source are secured, some kind of input is also required for you to connect - whether this is through head tracking, controllers, hand tracking, voice, on-device buttons or trackpads.
Total immersion is what everyone making a VR headset, game or app is aiming towards - making the virtual reality experience so real that we forget the computer, headgear and accessories and act exactly as we would in the real world. So how do we get there?
The basics
VR headsets like Oculus Rift and PlayStation VR are often referred to as HMDs, which simply means they are head mounted displays. Even with no audio or hand tracking, holding up Google Cardboard to place your smartphone's display in front of your face can be enough to get you half-immersed in a virtual world.
The goal here is to create what appears to be a life size, 3D virtual environment without the boundaries we usually associate with TV or computer screens. So whatever way you look, the screen mounted to your face follows you. This is unlike augmented reality, which overlays graphics onto your view of the real world.
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Video is sent from the console or computer to the headset via a HDMI cable in the case of headsets such as HTC's Vive and the Rift. For Google's Daydream headset and the Samsung Gear VR, it's already on the smartphone slotted into the headset.
VR headsets use either two feeds sent to one display or two LCD displays, one per eye. There are also lenses which are placed between your eyes and the pixels, which is why the devices are often called goggles. In some instances, these can be adjusted to match the distance between your eyes, varying from person to person.
These lenses focus and reshape the picture for each eye and create a stereoscopic 3D image by angling the two 2D images to mimic how each of our two eyes views the world ever-so-slightly differently. Try closing one eye then the other to see individual objects dance about from side to side and you get the idea behind this.
One important way VR headsets can increase immersion is to increase the field of view how wide the picture is. A 360-degree display would be too expensive and unnecessary. Most high-end headsets make do with 100 or 110 degree field of view, which is wide enough to do the trick.
And for the resulting picture to be at all convincing, a minimum frame rate of around 60 frames per second is needed to avoid stuttering or users feeling sick. The current crop of VR headsets go way beyond this - Oculus is capable of 90fps, for instance, while Sony's PlayStation VR manages 120fps.
Head tracking
Head tracking means that when you wear a VR headset, the picture in front of you shifts as you look up, down and side to side or angle your head. A system called 6DoF (six degrees of freedom) plots your head in terms of your X, Y and Z axis to measure head movements forward and backwards, side to side and shoulder to shoulder, otherwise known as pitch, yaw and roll.
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There are a few different internal components which can be used in a head-tracking system, such as a gyroscope, accelerometer and a magnetometer. Sony's PSVR also uses nine LEDs dotted around the headset to provide 360 degree head tracking thanks to an external camera monitoring these signals, while Oculus has 20 not as bright lights.
Head-tracking tech needs low latency to be effective - we're talking 50 milliseconds or less or we will detect the lag between when we turn our head and when the VR environment changes. The Oculus Rift has an impressively minimised lag of just 30ms. Lag can also be a problem for any motion tracking inputs, such as PS Move-style controllers that measure our hand and arm movements.
Finally, headphones can be used to increase the sense of immersion. Binaural or 3D audio can be used by app and game developers to tap into VR headsets' head-tracking technology to take advantage of this and give the wearer the sense that sound is coming from behind, to the side of them or in the distance.
Motion tracking
Head tracking is one big advantage the premium headsets have over the likes of Cardboard other mobile VR headsets. But the big VR players are still working out motion tracking. When you look down with a VR headset on the first thing you want to do is see your hands in a virtual space.
For a while, we've seen the Leap Motion accessory - which uses an infrared sensor to track hand movements - strapped to the front of Oculus dev kits. We've also tried a few experiments with Kinect 2 cameras tracking our flailing bodies. But now we have exciting input options from Oculus, Valve and Sony.
Oculus Touch is a set of wireless controllers designed to make you feel like you're using your own hands in VR. You grab each controller and use buttons, thumbsticks and triggers during VR games. So, for instance, to shoot a gun you squeeze on the hand trigger. There is also a matrix of sensors on each controller to detect gestures such as pointing and waving.
Headset head-to-head: HTC Vive versus Oculus Rift
It's a pretty similar set-up to Valve's Lighthouse positional tracking system and HTC's controllers for its Vive headset. It involves two base stations around the room which sweep the area with lasers. These can detect the precise position of your head and both hands based on the timing of when they hit each photocell sensor on both the headset and around each handheld controller. Like Oculus Touch, these also feature physical buttons too and incredibly you can have two Lighthouse systems in the same space to track multiple users.
Other input methods can include anything from hooking an Xbox controller or joystick up to your PC, voice controls, smart gloves and treadmills such as the Virtuix Omni, which allow you to simulate walking around a VR environment with clever in-game redirections.
And when it comes to tracking your physical position within a room, Oculus now offers an experience to match the HTC Vive, which it didn't do out the door. Rift owners now have the option to purchase a third sensor for $79 and add more coverage to their VR play area.
The problem, though, is that this still isn't on par with HTC. While two SteamVR sensors for the HTC Vive can deliver a tracked play space of up to 225 square feet, two Constellation sensor cameras from Oculus only provides coverage of 25 square feet, with a third camera sending the recommended space goes up to 64 square feet. That may change with Oculus Santa Cruz, the company's hi-spec standalone headset.
Sony is also hunting around this area, if a recent patent is anything to go by. The filing details a VR tracking system based on light and mirrors that uses a beam projector to determine the player's position, though whether such a feature would appear on the current device or second iteration of PSVR (or not at all) is all speculative at this stage.
Eye tracking
Eye tracking is possibly the final piece of the VR puzzle. It's not available on the Rift, Vive or PS VR but it will feature in FOVE's very promising VR headset. We also saw Tobii's eye-tracking tech in action in a HTC Vive. So how does it work?
Well, an infrared sensor monitor's your eyes inside the headset so FOVE knows where your eyes are looking in virtual reality. The main advantage of this - apart from allowing in-game characters to more precisely react to where you're looking - is to make depth of field more realistic.
In standard VR headsets, everything is in pin-sharp focus which isn't how we're used to experiencing the world. If our eyes look at an object in the distance, for instance, the foreground blurs and vice versa. By tracking our eyes, FOVE's graphics engine can simulate this in a 3D space in VR. That's right, blur can be good.
Headsets still need hi-res displays to avoid the effect of looking through a grid. Also what our eyes focus on needs to look as life-like as possible. Without eye tracking, with everything in focus as you move your eyes - but not your head - around a scene, simulation sickness is more likely. Your brain knows that something doesn't match up.
How to experience VR on your smartphone
Virtual reality is currently in its early phase. Granted, it hasn’t reached to the level of what we have seen in sci-fi movies (at least not yet), but it’s more popular than ever. Not just games, but with smartphone manufacturers focusing on the technology now, it is slowly finding its way into mainstream entertainment too. Today we have 360 degree videos and photos that are more immersive than ever. Soon, you’ll even be able to experience Facebook and YouTube in VR. Now the common misconception most of us have is that you need a high-end VR headset like Oculus Rift or HTC Vive to experience VR. However that’s not true. What if we tell you that you can experience virtual reality on your smartphone? Let us tell you how.
Understanding Smartphone VR
Virtual reality headsets like the HTC Vive and Oculus Rift depend on powerful computer hardware. In their case, the computer runs the software and the headset acts as the display. There is a completely different form of virtual reality on smartphones. To experience VR, all you need to do is slip your smartphone into a VR headset, and run the apps or games you want. Here, the smartphone acts as both, the display and the processing unit. With smartphone hardware only getting more powerful, the experience is bound to get better.
How to know if your phone supports VR
There is a good chance that your phone already supports VR. Almost all smartphones do today, across operating systems. What makes virtual reality more immersive is the ability to look around by moving your head. That is made possible, with the help of a gyroscope sensor on the smartphone. Most mid-to-high-end smartphones support one. If you’re current smartphone doesn’t support one, then know that you can still experience some VR apps. However, you won’t be able to look around in the game or app. The other optional requirement is a magnetometer sensor. Since you don’t have access to the smartphone screen when it’s placed in the headset, most headsets have a button on the outside to navigate in the app, like a mouse-click. This button works by triggering the magnetometer on the smartphone. Not all headsets though have a button.
VR Headset
Once you know that you have a VR supported phone, you need a VR headset. You can make your own headset at home with the help of some cardboard using a DIY guide. You’ll need to get some other things, like lenses and a magnet. One of the easiest options is to buy a Google Cardboard compatible VR headset.
The simplest and the most dependable option is one by Shinecon headset. These headsets might cost a little more, but their plastic built is more sustainable than cardboard to carry around. It’s also compatible with smartphones of different screen sizes. Besides that we’ve found the cushioning to be very comfortable for long use and the headband is adjustable to fit other people easily. You can get one from a Reliance Digital store closest to you.
Besides these, there are some premium headsets such as the Samsung Gear VR. They offer more features and some exclusive VR apps. However, they are only supported on a few select Samsung smartphones.
Virtual reality apps
There’s plenty of VR apps available at the moment for both platforms. You can download them from the respective app stores. Games of different genres are available for you to try. Most of the apps and the games are free, while some are paid. Not just games, there are plenty of apps that are just built around giving a virtual experience of places. The examples are endless. You can experience the life of an Astronaut living in space or go to the other end of the spectrum, by diving deep into the ocean. Every app comes with a new experience altogether. To make things even more immersive, some apps and games even let you use a wireless joystick to move around. Here are some of the must-try apps on your VR headset.
Google Cardboard (iOS and Android)
This app is your initiation to the VR experience on smartphones. It’s Google Cardboard’s official app. The app lets you use Google Earth, which lets you fly to different places around the world. You can use it to browse your smartphone photos and videos in VR. The app even carries a list of other VR apps that you can download, which is great. The good thing is it’s also available for Apple iPhones, not just Android.
YouTube (iOS and Android)
YouTube is home to pretty much all kinds of formats. VR videos are no exception. You can simply type in Virtual reality videos in the YouTube search and you’ll find plenty of videos that you can experience in the 360 degrees. Every 360 degree VR video comes with the VR icon. Just click on it and slip the phone in the headset. You can turn around and experience the views from any angle. It’s a truly immersive experience. This trend of making videos is getting more and more popular, as YouTubers use more 360 degree hardware to shoot videos.
VR One Cinema (iOS & Android)
Many people watch movies on their smartphone when traveling. It’s not the most immersive experience. VR One Cinema is the perfect app for that problem. The app makes you feel like you’re sitting at the cinema, where you can watch movies and videos on the big screen theatre.
Roller coaster VR (iOS & Android)
Enjoy the thrills of a high-speed rollercoaster sitting on your sofa. This app carries a list of swirly, rollercoasters based on different themes that you can try out. The tracks are designed in exotic locations so the ride is even more breath-taking. This app makes perfect use of the Gyroscope as you can look around the beautiful landscape.
Titans of Space (iOS & Android)
This is an educational app. It takes you on a trip across our solar system, where you can learn about the planets and compare their sizes. It is both educational and visually impressive. It’s one of the most of popular apps for VR. These few apps can give you a taste of VR. There are plenty of other apps that you should try out. With technology getting better each day and more apps available, the range of VR experiences is only going to get wider. When you’re buying a new smartphone, make sure it supports VR. If you want to know more, or which phones to buy, come visit a Reliance Digital store nearest to you.
Are Virtual Reality Headsets Dangerous for Our Eyes?
Virtual reality (VR) headsets are becoming increasingly mainstream. Their ability to create an immersive experience and transport us to another place makes them fascinating. However, little is known about the effects of this technology on our eyes and eyesight.
Most VR headsets contain two small LCD monitors, each projected at one eye, creating a stereoscopic effect which gives users the illusion of depth. These monitors are positioned very close to the eyes and have caused experts to wonder about possible negative effects, especially when used for long periods of time. These concerns are real, because eye strain is likely whenever one focuses on an object for an extended period of time, like when we watch a long movie or stare at our computer or smartphone all day.
Most VR headset manufacturers have put in place warnings for children. This is important because a child’s visual system continues to develop throughout childhood. Extended exposure to the awkward visual posture created by VR headsets can alter the development of focusing, tracking, and depth perception.
“Cybersickness,” a form of motion sickness associated with VR headsets, is also known to occur when there is a mismatch of visual information and known body position.
However, the news is not all bad. When used as instructed by an optometrist, some VR headsets enable vision development and improvement. Systems have been developed to improve visual acuity in amblyopia and to enhance eye-hand coordination, depth perception, reaction time, and eye coordination.
Virtual reality is constantly advancing and new technologies and applications regularly emerging. For now, the best advice is to pay attention to warnings that come with VR headsets, limit time spent in the virtual world, and ensure all users have regular comprehensive eye examinations with an optometrist to ensure eye health and contribute to overall health.
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