Virtual reality (VR) is basically a convincing illusion. It is designed to trick your brain into thinking that what you’re experiencing is reality – be that driving a getaway vehicle or blasting spaceships in outer space – when you’re probably just sat on your sofa in your pants.
How does a VR headset work?
The main part of making VR work is the concept of presence. The user must feel as though he or she is physically present in the experience; not merely observing through a window. For instance, when you’re watching a 3D film at the cinema, your brain knows what you’re seeing is not reality, since all you have to do is turn your head away from the screen and the illusion will be broken.
A VR headset prevents this break from virtual reality. You can turn whichever way you want, move forwards, backward, or even jump on the spot and you’ll remain locked in the experience, which only terminates when you remove the headset.
Inside the VR headset (of which there are many), there are two screens with a viewing field of 110 degrees. This means your peripherals won’t be able to detect screen edges or any other real elements. Each screen displays a slightly different image for each eye – a trick called Stereoscopy.
Stereoscopy is the concept of mirroring your eyesight’s natural bilateral vision. If you close your left eye then open it while closing your right eye and repeat, you’ll notice that things move from side to side. But when both eyes are open our clever brains merge both lines of vision together to create one image. In VR, two slightly offset images are shown on the screens so that your brain naturally merges them the way it would in reality.
So once you’re in the virtual world, just where are you exactly?
This is where tracking comes into play. If you move your head and the display lags behind, you’re probably going to start feeling very sick. So all the information is quickly pieced together from different sources. These sources include a gyroscope, an accelerometer (which measures your speed), and a magnetometer to correct ‘drift’.
Most VR headsets are covered with tiny LED lights, whose signals are picked up by a camera (placed either above or below your TV). This way, the precise location of your headset and therefore your location in the virtual environment can be calculated.
But why has it taken until now for VR to hit the consumer market?
Well, the cost is one reason and comfort/practicality is another. But the slow rise of VR can mainly be attributed to limited technology over a long period. And since the breakthrough was made by the tech startup Oculus a few years ago, there have been dozens of issues that needed ironing out.
For example, ‘cyber sickness’ was a common side effect of VR, due to mismatched signals being sent to the brain, e.g. when you are running in VR but sitting down in real life. Unsurprisingly, this caused nausea and spoiled the experience.
However, now VR headsets can reduce or even completely eliminate cybersickness altogether. This is thanks to the ‘lighthouse’ tracking system, which allows users to walk around in a 5x5m space both in reality and the virtual space.
What’s more, the fact that the user must use a controller, keyboard, or mouse to control their movement in VR means there is a constant separation between the virtual and actual environments, preventing any sort of Black Mirror style, stuck-in-VR-forever type scenario. But the controller requirement doesn’t mean you can’t touch things in VR – trackable controllers allow users to physically interact with their virtual environments.
Essentially, the VR headset tricks your brain into believing things that aren’t real but not to the extent that it is unsafe or nauseating. It’s one very cool toy.