Virtual reality is a completely virtual environment that users can interact with and move around to explore. How it works is almost like magic, involving using a screen mere inches from your eyes to trick your brain into believing you are looking into what could be an immense place, stretching off into the vary far distance.
This trickery is possible by the arrangement of two images, each from a very slightly different point of view to recreate the effect of seeing out of both eyes – each eye sees a slightly different view to the other, as you can check by closing one eye, then the next and seeing how what you see changes. These two images, one seen by each eye, creates the illusion in the brain that you are standing in the environment depicted.
This process – of having two almost identical images placed side by side – is not a new one. The process has long been used to produce stereoscopic images. These images are especially useful when exploring new terrain, for mining expansion, archaeological examination and so on. When the images are viewed from the right position, usually from directly above the images, some twenty to thirty centimetres away, the landscape appears to be three-dimensional and any interesting features ‘pop’ out more clearly than when viewing a static two-dimensional image.
Virtual reality has taken these principles, and used modern technology on them, with a mobile phone screen replacing the two printed photos and a headset taking the place of a viewer lining their head and eyes up in precisely the right place, then holding themselves in that position for as long as it took to examine the area.
A person’s normal field of view (FOV) is around 180°, with peripheral vision and head movements bringing it up to around 270°. This means that the images and footage used in virtual reality need to be a minimum of 180° views, although some offer full 360° views.
Once the eyes have been fooled, sensors placed all around the room that you are in, in the hand-held controllers and in the headset all come into play. These sensors let the software know what you are doing, if you are standing or sitting, or if you are walking around and are in danger of walking into a wall. The efficacy of these sensors depend on how many cameras are used by the virtual reality system – Sony’s PlayStation VR only uses one and frequent ‘loses track’ of the user, while HTC’s Vive uses base stations in conjunction with the camera to ensure that even the smallest movements are picked up.
Your progress in virtual reality is made by you making physical movements or by operating the handheld controllers that enable you to open doors, lift objects and throw them. Controllers that are built into gloves are the most authentic feeling, but it is quite easy to immerse yourself into a virtual world even when having to remember to use a handheld controller the right way.
So now you know a little bit about the basics of how virtual reality works – get out there and try it!