HOW VR HEADSETS ACTUALLY WORK
How a lens, some sensors, and more can transport you to awesome new worlds.
Virtual reality might seem like black magic, but the truth is each headset is a carefully engineered product, blending cutting edge tech with more than a few clever tricks designed to make you forget about everything except for what’s on the screen. We’re breaking down how these headsets work and taking a look at the individual components that make virtual reality such a convincing experience.
Lens
The lens is one of the most crucial elements of what makes virtual reality so convincing. These lenses fool your eyes into thinking you’re looking at a vast depth of space rather than two flat displays inches away. The lens achieves this by focusing the light to make it appear as if the displays were an infinite distance away.
Many headsets have opted to use special Fresnel lenses, which achieve the same effect as bulkier curved lenses with much less material by using thin, circular arrays of prisms. These lenses also magnify the headset’s built-in display so that you don’t notice the edges of the screens, making the image encompass your entire field of view.
Display
High performance displays are another important factor in convincing virtual reality. They must have a density of pixels to display clear images, but also display them at a fast enough rate to make movement in VR smooth.
“High-end headsets use dual screens to create a stereoscopic 3D.”
Both the HTC Vive and Oculus have opted for two 1080×1200 displays, one for each eye, that are intended to display images at 90 frames per second — affording users smooth movement and a wide 110 degree field of view that encompasses much of your range of vision.
High-end headsets also use dual screens to create a stereoscopic 3D effect similar to the Nintendo 3DS. Each screen displays a slightly offset image to each eye that our brain then joins together into one image, creating an illusion of depth in the process.
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Gyroscopes provide a much finer measurement of the rotation of an object by tracking subtle shifts in orientation along an axis, like tilting your head slightly or nodding.
The Samsung Gear VR forgoes more advanced infrared tracking methods to use an inertial measurement unit (IMU), which is somewhat of an all-in-one device using magnetometers, accelerometers, and gyroscopes. Unlike in most smartphones, this IMU is created specifically to reduce lag and improve head tracking performance.
Infrared Tracking
Both the Oculus Rift and HTC Vive use infrared lasers to track the movement of the headset, but each one has their own method.
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Source: IGN