AR is all about bringing digital information and overlaying it over the real environment. The only difference from VR is that it creates a totally artificial environment around you, whereas AR uses the environment around you and overlays the digital information over it. For VR, you will require a VR device, but for AR it can be achieved by simply using a smartphone, tablet, or dedicated VR devices.
AR can be categorized into three different types based on the display types:
- Screen-based
- HMD-based
- Projection-based
A common example of screen-based AR is overlaying digital information over smartphones or tablet camera displays. For example, you switch on and point your smartphone/tablet camera over an object, and the application recognizes that object and overlays that object information, such as the price or description, as digital information over the object image.
Another example of screen-based AR is the video game Pokemon GO, in which, based on the user's location and direction, digital characters are overlaid over video images.
User is viewing augmented object using smartphone
In the preceding figure, a user is viewing an augmented object, that is, the elephant's digital object is overlaid over the video frame. This is an example of screen-based AR.
Using AR HMD devices, digital information is overlaid directly over the user's view of the real world. So, there is no need to hold any screen to view the digital information. Digital information is directly rendered over the view area of the user's eyes.
HMD with information overlaid over the real view
In the preceding image, the user is using a head mounted AR device to view the physical element in front of him. Within the view of the user, the AR device embeds information about the physical object and provides them with a more immersive experience.
User projection-based AR, a projection is rendered on the target surface itself. This target surface could be anything, such as building, person, room, and so on. To render this kind of projection, the system needs to know the exact dimensions of the target surface, and then using single/multiple projectors, it renders the projection on the target:
Phone dialer pad projection over the hand
In the preceding image, the user is viewing a projection of the phone dialer on the palm of their hand.
Applying AR is quite different from applying VR. AR applications are more focused on integration scenarios with the real world. Some are as follows:
- Gaming: With the release of the Pokemon GO game by Niantic, the demand for AR games has picked up drastically in the market. A lot of companies are coming up with AR games and launching them.
- Architecture/construction/archaeology: AR can be used to visualize completed buildings for in-progress or upcoming building construction. Digital architecture/building images can be overlaid over the real view of the property or ground.
- E-Commerce: Businesses can't reach each customer with demo-able physical product, and opening showrooms is every city is a costly business, especially for start-ups and newcomers in the market. So, reaching out to customers through AR, online furniture retail companies, for example, allows users to consume AR through smartphones, let them visualize their furniture products, and enable them to design their house interiors.
- Education: Traditional education systems require hands-on instructions and real/prototype equipment to explain it better to students. With AR, teachers and students can visualize the same equipment in virtual mode, with very similar training instructions as with an actual device. Another implementation of AR in the education system is distance learning, where students and a teacher very far away, can use VR devices for interactions and virtual classrooms.
- Medical: In the medical field, there are different imaging techniques for various requirements, such as X-ray, ultrasound, and magnetic resonance imaging (MRI), but there is no consolidated view for medical practitioners. AR could be used for these scenarios, where the output from different imaging techniques could be overlaid over the patient and give a consolidated view to medical practitioners.
- Industrial design: AR is being used for designing, sharing ideas, and brainstorming design views among different designers and architects and supplies quick feedback and brainstorming cycles. Earlier, the same process used to take a long time, as designers used to create physical prototypes and then discuss them.
- Travel/navigation/tourism: AR is also used for developing navigational applications; for example, travel-related digital information is overlaid on the vehicle windscreen, which helps the driver in real-time navigation without looking at any other device, such as a GPS or smartphone. AR is also used to develop travel-related applications, which help the user with location-specific information of the place where the user is currently placed, such as historical information about tourist places, or information about nearby restaurants and cuisines.