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Augmented Reality Explained In 2 Minutes

posted Mar 14, 2018, 5:47 AM by Rohit Bhaskar   [ updated Mar 14, 2018, 5:48 AM ]


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We've all heard of augmented reality at some point in our lives. Most of us have probably even seen it in action in some form or another. But lets dive into it to really understand what Augmented Reality is.


Introduction:

‘Augmented’ reality literally means adding something to the existing reality and making it even larger.

Ok,... so what is a technology doing with such a name? Let’s look away from the screen that you are currently reading from. Yes, this is reality. The physical world around you, your friends, your phone, your slow internet connection, are all a part of ‘reality’. Now, look back into your screen (you are already ;p). This world inside your phone where you play games, socialize with other homo sapiens and enlighten yourselves is a virtual world.

Wouldn’t it have been wonderful if all this magic was happening right inside your ‘reality’?? How, you ask? Augmented reality is the answer. In this technology you literally take virtual world graphics (sometimes even audio and other sensory enhancements) and project it onto your real world objects. Let’s try to build such a magic device (yayy..finally engineering!)


Ok, so let’s say you(Mr.potato) have found your friend’s head(Mr.tomato) to be a very interesting target and want to project a pair of bunny ears onto them. You would first of all need a screen to project that image. Let’s say you somehow found the right screen. But Miss Pumpkin sitting at some other place isn’t able to make out that image because of the different perspective from which she is viewing it. So our device isn’t any fun unless it is able to project the image to all the viewers in a correct perspective i.e. it should be able to track the user’s ( here potato and pumpkin) motion RELATIVE to the object (here tomato’s head...poor thing). This right away requires us to have motion tracking sensors in our magic device. Also note that at this point of time, our device requires a separate display for each user. Now all of this of course can’t happen without a powerful computer (but we desire it to be small coz every time I want a pair of bunny ears projected on someone’s head i don’t want to carry my desktop with me)


Thus we have identified the main components required for any Augmented Reality device:

  1. Display
  2. Motion tracking and orientation sensors
  3. Computer
  4. Some software that does all this job on the computer.


Display:

Three types of displays are used in AR devices:
  • Head Mounted Displays (HMD): These displays superimpose virtual graphics on the user’s physical view of the world. HMD are either an optically transparent or video transparent devices. In an optically transparent display device, partial silver mirrors are used to pass the views of the real world through a lens. At the same time the virtual images are reflected into the user’s eyes. Some basic products that use such displays are Sony Glasstron, Microvision NOMAD and so on.
  • Handheld Displays: Such displays are small in size and will easily fit in one hand. These devices use video transparent techniques to relate the virtual world to the real world. This display technology is the biggest success for Augmented Reality till now. Since they are easily portable and due to the bulk use of camera phones, they are used widely.
  • Spatial Displays / Spatial Augmented Reality (SAR): The graphical image is related to physical objects by using a digital projector. The only problem is that the user will have no contacts with the display. The main advantage of such a device when compared to other displays is that the user doesn’t have to carry the equipment along with him. Thus the users can easily see each other’s faces. Since a projector system is used, these displays have better resolution than the others. The resolution can be further increased by expanding the display area by using more projectors.


Motion Tracking:

We may encounter motion wherein either the target object (tomato’s head) is moving or the user (potato) is moving or maybe both are moving. We solve this problem by resorting to the age old and dreaded physics concept- ‘relative motion’. Thus we now place ourselves in the frame of reference of the device and first find out the target’s coordinates relative to us and then find it’s orientation relative to us. The sensors used for finding coordinates for example maybe a GPS module, a camera, wifi/nfc signals from the target(pretty similar to how your cell phone network finds you) etc. The sensors used for tracking motion mainly include accelerometers, gyroscopes(angular velocity,angular position),magnetometers(orientation with earth’s magnetic field) etc.

Thus we now have the information about the whereabouts and the motion and orientation of the target. Pretty set. All that’s left to do is for the computer to appropriately process the image-to-be-projected and project it onto our object and voila! You have made your very own AR device! (now you may pat yourselves.)


Software:

Now with this kind of technology you can only imagine what tech-giants like Google and Apple would be upto. Apple has recently released it’s own AR development kit called AR kit using which you can turn your Iphone into an AR device. Google already has under it’s belt the famous ‘Google glasses’ where it overlays information about the things that you see right in front of your eyes. Now this is a common trend you will see in most of the technologies. They are made ‘open-source’ with some user friendly tools using which even a mortal man (non – programmer) can build cool stuff- an excellent example being android studio! Similarly there are a bunch of popular softwares that will help you develop AR applications for your smartphone.



Well, that's that. Here we end our post on augmented reality. Hope you understood what augmented reality is and what are its main components. This post only scratches the surface though, there is a lot more to this that what we have told you ;p. So read up, Google and enjoy this new technology ;)



- Pradeep Suresh