Virtual- and augmented- reality are two hot terms in the tech world. There’s a good chance that you’ve come to this site because you Googled one of these terms to find out more about them. The good news is that you’re in the right place to get an easy, plain English explanation of both virtual reality and augmented reality. By the time you get to the end of this article you should be in no doubt about what either of these mean and you can impress all your friends with your new knowledge.
So What’s Virtual Reality?
Most people immediately think of virtual reality as something that involves strapping a bulky pair of goggles to your face, but the concept itself isn’t locked to that particular approach. Virtual reality refers to any method that aims to replace your perception of reality with new perceptions meant to fool you into thinking you’re somewhere other than where you really are.
If you truly want to split hairs about it, we’ve had crude forms of virtual reality since before we had electricity. For example, there have been panoramic paintings meant to be displayed on the inside of a circular room. Paintings of great battles were popular. The idea was that if you stood in the middle of the room you’d feel like you were there, although it was an event in the past.
Since then we’ve had the computer revolution and the rise of computer-generated imagery. Modern virtual reality mainly makes use of computer-generated sights and sounds to fool you into believing you’ve been transported into another place.
Tools of the Trade
There are a lot of technologies that have been developed over the years that count as virtual reality. For example, a big professional flight simulator that has the user sit inside a replica cockpit and look out of the windows to see a computer rendering is indeed an example of virtual reality.
If we’re talking about the actual consumer VR you and I are most likely to run into, there are a few common pieces of hardware you’ll see time and time again.
The HMD, or head-mounted display, is the most iconic piece of VR hardware. It looks a little like a pair of scuba goggles with no glass lenses. The HMD usually contains display technology of some sort to beam images to each of your eyes. It might also have built-in headphones so you can hear the sounds that go along with the visuals.
The HMD will also contain some form of head-tracking technology, which takes the motion of your head and then changes the images to match them in an expected way.
While the HMD lets you control where you’re looking, it’s not a complete solution to the problem of moving your virtual body around. To do that you need another controller to represent your “legs” and “hands”. The simplest solution is a standard video game controller – the sort that comes with your Xbox or Playstation. In fact, the premium home VR systems almost all ship with such a controller.
If you’ve ever played video games using a gamepad controller, this will feel pretty familiar. The main difference is that you look around with your head rather than by moving a stick with your thumb.
Beyond the gamepad controller, there are also motion-based controls that give a much more immersive experience. These can track the motion of your hands, and buttons on the controller can simulate interactions such as picking an object up or firing a gun.
Going beyond even this, if you’re really flush with cash there’s the option of haptic gloves, which use methods such as tiny air bladders to stiffen and release your fingers. This can make it feel like you are really holding an object. These sorts of gloves are not mainstream at this point and the big VR games and software generally don’t support them.
So What’s AR Then?
“AR” is short for augmented reality, which is like a cousin of virtual reality. To be honest, augmented reality has a much bigger commercial future than virtual reality and you’ll see why soon as I explain it to you. While both VR and AR send stuff to your senses that aren’t really there, AR doesn’t completely blot out the real world. Instead they project virtual data onto a layer between you and reality, thereby augmenting it. Get it? Augmented reality.
The HUD in a jet fighter is a really simple example of AR. It shows some basic info such as the craft’s speed and attitude and is mainly useful because the pilot does not have to take his eyes off the world to read instruments.
That’s not really what the AR people are talking about, however. Instead, imagine seeing a tiny dinosaur stomp across your desk or a giant TV on your wall that isn’t really there. That’s the augmented reality that has everyone excited. The term “augmented reality” is actually starting to fall out of favor and is being replaced by the more appropriate term “mixed reality”, because these technologies aim to seamlessly mix virtual and real sensory inputs with one another.
I See You!
AR technology needs to know something about the outside world in order to weave digital data into it. This means that it requires sensors that would serve no purpose in VR. Cameras are the primary sensor for AR applications. Without a camera you can’t project anything onto the real world, because the software has no idea what the real world looks like to begin with. Additional sensors may include ultrasonic sensors and specialized cameras that see in a part of the spectrum that we usually don’t care about, such as infrared.
All these sensors have their information interpreted by sophisticated software. The level of sophistication varies.
What Does AR Hardware Look Like?
That’s an interesting question, since we nearly all have an AR device in our possession. Your smartphone is a serviceable augmented reality machine; you could hop on your app store right now and find a heap of AR apps that will demonstrate this to you.
That’s old news. What’s really interesting are AR head-mounted systems where you don’t look at a screen but at the world directly. Many mobile VR HMDs have a camera pass-through that let you experience a rather crude form of of AR, but the most advanced systems use a special transparent material that has projectors to beam images into it, seamlessly blending what you see through the glass with what you see on the glass.
The face of advanced AR today is therefore a head-mounted system similar in shape and size to a VR headset. In the future these devices are going to be less and less obtrusive. Advanced wearable technologies will be so small and compact that you won’t even know that someone is wearing them. Already companies like Google are building basic AR technology into eyeglasses. There are research projects underway to build AR displays into contact lenses. One day the AR gear might be in your body. A company called Omega Ophthalmics has created a special capsule that can be safely implanted inside the eye where your lens is; the space inside this capsule can house some yet to be invented technology.
Mixing VR and AR
Both of these technologies are going to have a significant impact on our future and both of them are going to have a place. I foresee a future where we’ll be using the same hardware to provide both AR and VR experiences. Indeed, we’ll seamlessly shift between full, immersive VR to medium AR and light or no AR.
Today there’s a clear defining line between VR and AR, but I don’t think that’s viable in the long term. It may sound radical, but throughout this century chances are that you’ll spend each day at different levels of virtual depth.