How Virtual Reality Works

If you’ve ever donned a virtual reality headset, you’re familiar with that feeling of being transported: the conflicting feeling of knowing where you are but your mind somehow feeling disconnected from it. While you may just be standing in the middle of your living room, virtual reality (VR) makes you really feel as if you’ve teleported to a whole other world.

But how does VR technology manage to pull this off? Trying to understand how VR works without a little background knowledge is likely to leave you feeling more lost than someone figuring out motion controls for the very first time. Let’s take a look at some of the basics of how VR headsets work before diving into some of the finer details.

An Overview of How a Virtual Reality Headset Works

Virtual reality technology is evolving and being implemented into everyday life at an incredibly fast pace. While its most accessible and popular application at the moment is to play video games, VR is quickly expanding into both the home and workplace for myriad different uses. Each day, VR developers are coming up with new and fascinating ideas about how to work virtual reality into our lives. But despite its growing popularity, few people understand why virtual reality works.

To understand how a VR headset works to bend reality, we must first understand how human beings perceive reality. We create our sense of reality through the use of our senses. What we can see, feel, and hear is what our minds deem to be real. Using this principle, VR developers are able to expertly craft entirely new worlds that are specifically designed to deceive the senses.

Replacing what our senses absorb is the basic foundation for how a VR headset works. It shuts out our physical environment and swaps it for a virtual one. The headset uses integrated technology, such as magnetometers, gyroscopic sensors, and accelerometers to track your movements, as well as software that generates the environment around you. All of this works together to create a feeling that you’re fully interacting with a world that isn’t really there.

The Specifics of How VR Works

Now that you’ve got an understanding of the basic principles of how VR functions, let’s take a more in-depth look at some of the specifics. These are the nitty-gritty components that are able to trick your brain into believing it’s somewhere entirely different from where you’re standing.

Head and Motion Tracking

Interactivity is one of the key components of making a virtual setting feel real. Users should be able to move around the landscape, pick up and use objects, and look around in all directions, while the environment reacts in perfect sync to those movements. But how do VR headsets accomplish this?

Tracking features in VR headsets allow users to explore a virtual environment using either three degrees of freedom or six. This relates to the fact that there are a total of six different ways to track a certain object’s movement within the artificial space. These are:

• Three degrees of freedom that track movement based on the X, Y, and Z axes. These may be referred to as pitch, yaw, and roll.
• Three degrees of freedom for translational movement along those same axes. This is interpreted as moving up or down, left or right, and forward or backward.

By using magnetometers, gyroscopic sensors, and accelerometers built into the headset, as well as external sensors on occasion, VR technology is able to track your body’s movements along these degrees of freedom. This allows you to feel as though you are actually moving through and interacting with a completely artificial environment. This combination of environmental interactivity and reactivity to your movements is one of the main ways VR makes you feel as though you are really there.

Frame Rate and Field of View

Generating a realistic field of view (FOV) is simultaneously one of VR technology’s greatest strengths and greatest weaknesses. For those who don’t know, an FOV is how much of your surrounding environment you are able to observe.

Current-generation VR headsets are able to create an FOV for users of approximately 180 degrees. This is good enough to trick our minds into questioning whether or not we’re in a real space, but not outright convince us. This is because a human’s actual FOV comes in at around 220 degrees. This slight but important difference in the FOV is one of the shortcomings of VR. However, the technology is still evolving, and headsets in the future may be able to get closer to the natural feeling of 220 degrees.

FOV alone isn’t enough to create a convincing experience for your sense of sight, though. Your experience also depends in part on the frame rate of what you see. This is the speed at which your eye is exposed to new images, which is given in frames per second (FPS). The human eye can detect about 1,000 FPS, but only a fraction of that is interpreted by the brain. VR engineers have discovered that any experience below 60 FPS tends to cause disorientation or nausea in the user. So moving forward, most VR technologies are aiming to hit somewhere around the 120 FPS mark to create a smoother experience.

Sound Effects and Audio

While crafting a compelling visual experience is undoubtedly crucial to the functionality of VR, sound is equally as important. It’s nearly impossible to become fully immersed in a virtual world based on visual cues alone. This is where spatial audio comes in.

Spatial audio is sound delivered to your ears in a 360-degree fashion. It’s able to replicate sounds that are coming from different points of origin. That means that if something were to happen behind you in the virtual world, spatial audio would make it sound as if it was actually coming from behind you. It’s the same for sounds from your left, right, above, below, or anywhere else in the environment.

Working in congruence with the visual cues, these audio cues help your mind to believe that you’re in a real, physical space. When you hear something that appears to be coming from your left and turn your head in that direction and see it in front of you, this creates a far more immersive experience. It’s “proof” to your mind that the audio feedback you hear around you is coming from a tangible 3D space.