How does mobile VR work?

May 15, 2017

Mobile VR

So you’ve got your headset, and you’ve tried out VR a couple of times on your device. Being the inquisitive mind that you are, it’s got you thinking, “just how does this trickery work?” Being technology, of course it’s complicated – but that’s why we’re here to save the day! Let’s break down the main components of mobile VR, and go behind the scenes to see just how the magic happens.

Tricks of the mind start with the eyes

The first thing you’ll notice about Google Cardboard VR apps is that the screen is doubled. This is called a stereoscopic display, and if you look closely when your device is out of the headset, you’ll see that the left and right sides of the screen show slightly different angles of the scene around you. This simulates the space we have between our eyes and helps to simulate realistic depth, along with other graphical tweaks.

World Traveler VR

Notice the subtle difference in angle between the left and right lenses.

The illusion of movement

Remember the first time you tried VR on your smartphone? Maybe you were amazed at how even subtle head movements were picked up, and when you looked around it was just like looking around a real dimension. This is thanks to three sensors buried in your device that are actually used for a number of other functions in addition to VR: the gyroscope, the accelerometer, and the magnetometer.

Samsung Gear VR

Mobile device companies such as Samsung have invested in their own VR headsets, such as the Gear VR shown here (Image: Samsung)

Firstly, the gyroscope picks up when your device is twisted or rotated at an angle, while the accelerometer is used to detect when the phone is being moved up, down, left, or right. The magnetometer is used like a compass, and picks up whether you’re facing north, south, east, or west. Combined, these three sensors work together to accurately portray where you’re looking when using VR. Nifty!

Feeling queasy? Check the FPS and refresh rate!

The amount of FPS, or Frames Per Second, a device can achieve varies from unit to unit – FPS is how quickly your phone’s insides can show images per second. On the other hand, refresh rate relies on your device’s screen resolution and shows how quickly the screen can show images per second. Both the FPS and refresh rate need to be very close to the same amount, or else you’ll start to notice a motion sickness that has come to be known as “virtual reality sickness” or “cybersickness” – not a pretty sight! The best way to minimize this? Use higher quality and higher-end devices (think Samsung Galaxy S8 or the iPhone 7 Plus) that are strong on the inside as well as have higher resolution screens.

Oculus VR

A discrepancy between the FPS, refresh rate and FOV of a VR headset can result in latency, or lag, that can cause some to experience queasiness. (Image: Oculus Rift Forums)

Another important factor in VR is the Field of View (or FOV) that comes into play – FOV is the amount of objects and space you can see around you at any one time. While humans have a natural 270 degree FOV, Google Cardboard and Daydream only offer an FOV of around 90 degrees. This narrow field of view is noticeable but fine for most people, though for others it may quickly lead to a case of the cybersickness mentioned above! The best thing would be to try out different kinds of mobile VR headsets until you find one best suited and most comfortable for you.

Immerse yourself in virtual soundscapes

The eyes aren’t the only thing – the ears are just as important! In order to really put you in another world, realistic sound is crucial. 3D audio, or spatial audio, replicates real sound environments by having audio placed at different areas around the scene that vary in volume and intensity depending on the direction you’re facing. This gives off the illusion of a bomb going off right behind you, something whispering in your left ear, and more engaging audio effects while you explore VR environments.

VR - Spacial Audio

A representation of how many places 3D audio can stream from (Image: Google)

The current state of VR is rapidly growing and changing, with businesses beginning to look more and more towards a bigger and brighter future for the field (just look at the $2 billion Facebook acquisition of PC-based VR headset and software Oculus!). Alongside augmented reality – apps in the vein of Pokemon GO and Snapchat – the quality of VR will continue to increase while the software becomes even more sophisticated. A future where virtual reality is as easily accessible as a TV or computer? We’re already halfway there!

Quick Summary

  • The doubled screen (stereoscopic display) showing a slightly different angle on each side creates the illusion of depth
  • Your device’s gyrometer, accelerometer, and magnetometer work together to simulate realistic directional movement
  • FPS (Frames Per Second) and refresh rate need to be close to the same amount in order to lower the effects of “virtual reality sickness”
  • 3D audio (or spatial audio) places sounds at different volumes and intensity between the left and right speakers or headphones to further create a feeling of space

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