How do virtual reality glasses work

 

Have you ever stopped to think about how virtual reality glasses work and how they are able to “trick us” and provide a sense of immersion in a certain content?

Although the number of devices like this has grown in the last five years, virtual reality glasses are still a type of accessory that arouses curiosity in many people. The logic of operation of these electronics is quite simple, but the result is impressive.

Games and movies have taken greater advantage of this, providing a sense of immersion that, in fact, makes us think that we are in another dimension. Let's understand how it is possible that this accessory is able to deceive us and provide incredible experiences.

How do virtual reality glasses work?

The models currently on the market work in compatibility with a PC or smartphone . Computers and cell phones are responsible for processing the information that will reach our eyes.

The existing models can be from the most advanced, with comfortable foams around the eyes and nose and adjustments to secure it on the head, to the simplest ones, made with cardboard sheets. The results, of course, differ slightly, but in general the way of functioning is the same.

If we sat in front of the PC screen or put the smartphone in front of our eyes, it would not be possible for them to give us a sense of immersion.

Virtual reality glasses use one or two LCD displays per eye. In some cases, lenses can be placed between your eyes and these screens. This allows the user to adjust the distance of the image in relation to his vision.

These lenses are responsible for giving a new shape to the way we see images, in an effect called stereoscopic 3D. If you bring your eyes close to any object and look at it steadily you will notice an effect very similar to what glasses do: you see two images as if they were one.

The secret of head tracking

In order for this immersion to work even better, virtual reality glasses also have head tracking capabilities. From a calibration, the software “understands” where you are on a given map and traces a possible area around you.

Thus, when moving the head, this movement is understood and on the screen the images move in the same direction. Looking up, down, sideways or back causes the scene to be filled before your eyes. It's like you're literally in the game.

This type of system is called 6DoF ("  six degrees of freedom "). To understand it, we need to take a look at basic mathematics, more precisely the concepts of Cartesian coordinate system.

In it we have the axes “X” (width), “Y” (height) and “Z” (depth). What  head tracking does is to understand how deep the head is in relation to height and width.

We still have to think about the issue of latency, that is, the response time between the movement of the head and the understanding of this movement by the software. The lower the latency, therefore the response time, the more accurate the commands are. The most efficient systems need to have latency less than 50 milliseconds.

Tracking body and eye movements

If the movements made with the head seem consolidated in the virtual reality glasses, the developers are now working to improve  body tracking  and  eye tracking . That is, the way the movements of the body and eyes are recognized.

In the case of games, the joysticks have technologies similar to that of  head tracking  so that the system can understand where the control is in relation to the scene - and from the position and movement, an action is configured.

Eye movement tracking technologies are also available, but have not yet been incorporated into virtual reality glasses. When in operation, users will be able to direct the focus of the action from side to side without having to move their heads.

In addition, the flashes will serve as a control mechanism. An example of this can already be seen in simple games on Instagram , in which the blinks serve as a "jump" of a character. It is a matter of time before a similar feature is integrated with virtual reality glasses.