What is augmented reality?
AR leaves the room exactly where it is and puts information on top of it: a 3D model, a label, a technical diagram, an animation.
The room stays, the information arrives
Where VR shuts the real world out, AR keeps it in view and adds to it, through a phone screen, a tablet, or a pair of transparent smart glasses.
The person keeps their footing, their colleagues and their surroundings, and gains a layer of information that sits exactly where it is needed.
How augmented reality works in practice
AR relies on cameras, sensors and computer vision to read the physical environment and anchor digital elements in real time.
Ronald Azuma's 1997 survey defines it by three characteristics: it combines real and virtual content, it is interactive in real time, and it registers virtual objects accurately in 3D space. Azuma, 1997
Mobile AR, on the phone in your pocket
Standard smartphones and tablets use their rear cameras, gyroscopes and accelerometers to place digital objects onto surfaces.
Google's ARCore documentation describes motion tracking as following distinctive camera-image points to work out the phone's position.
It describes environmental understanding as detecting horizontal, vertical and angled surfaces, and light estimation as matching a virtual object's lighting to the room. Google ARCore documentation
The building blocks
Every AR display, from a phone to a pair of glasses, is built from the same handful of techniques for finding the room and staying locked to it.
What it feels like to use AR
The room stays visible while the digital information sits over it. A person keeps moving, keeps talking to the people beside them, and stays aware of obstacles and hazards.
Through a screen, or through the lenses
On a phone or tablet the view is framed by the screen, which makes it accessible but means holding the device.
On smart glasses the graphics appear directly in front of the eyes, though the field of view where overlays are visible is typically narrower than natural peripheral vision.
Where augmented reality is commonly used
AR is useful when the information needs to appear beside the object, the place or the task it explains.
Augmented reality in practice at PTR
PTR's live AR is a build you can point a phone at today.
The AR Business Card
Point a phone camera at the PTR card and the build opens in the browser, with nothing to install. It runs on PTR Labs. PTR also builds interactive AR overlays for print material, physical spaces and artwork. PTR's augmented reality page
Common confusions about AR
What AR gets mistaken for, and the difference in each case.
Is augmented reality the right fit?
The conditions that make AR the obvious choice, and the ones that mean another format will serve better.
The short version
What adding to the room buys you, and where it stops.
Added to the world, not replacing it
AR adds digital content on top of the real world without replacing it. That is what makes it useful for hands-on, in-the-moment guidance, and it is also why AR alone cannot let digital objects react to real surfaces the way mixed reality can.
See how augmented reality is applied in enterprise and learning on the XR overview →
Still have a question about augmented reality?
Sources and further reading
AR definitions, a review of training systems and ARCore developer documentation.
A Survey of Augmented Reality
Presence: Teleoperators and Virtual Environments, MIT Press. The three-part definition this page uses.
How It Works: ARCore developer documentation
Motion tracking, environmental understanding and light estimation, as the vendor describes them.
Systematic Review of Augmented Reality Training Systems
The review of 64 published systems behind the effectiveness note above.
A Taxonomy of Mixed Reality Visual Displays
IEICE Transactions on Information and Systems. The continuum that places AR near the real end.
