Augmented Reality is not a new topic to most of the people who have a little knowledge about new technologies. The term has been around the world since the beginning of human-computer interaction. But it has been hidden due to its complexity compared with the then available computer hardware. Nowadays, with the fast spread of ‘flagship’ fingertip enabled gadgets due to the advancement of technology, Augmented Reality has become a hot topic since the mid of last decade (the 2010s)

There has been much research going around for the matter of Augmented Reality since the beginning. These researches have paved the ways to create new startups and massively funded companies such as Magic Leap, Daqri and Vuforia. Despite their differences in their business models, these companies have given Augmented Reality a boost in the tech industry.

Augmented Reality in General

Many Augmented Reality use cases are released for the general public through smartphones, mainly due to their high processing power and inclusion of additional sensor hardware. Earlier stages of Augmented Reality through smartphones focused on “Marker-based” methods, which uses a coded image to track the surface and virtually augment a 3D content on top of it. Attaching coded images to everyday use cases seemed unnatural, the researches created novel marker-based methods which use standard photos and aesthetically pleasing flat designs to track and identify the surface.

With the introduction of Microsoft Hololens, Googles AR Core and Apples AR Kit, the AR industry has massively enhanced to far better use cases than just placing 3D content on an image. Marker-less augmented reality uses highly optimised and advance artificial intelligence algorithms to detect and track the flat surfaces only with a 2D photo. Since Hololens uses multiple sensors for efficient tracking for its custom use cases, the context of this text can leave it aside for the moment.

The marker-less era went viral with Augmented Reality enabled games such as Pokemon Go and Apples efficient measurement tools which uses just the camera to offer immersive physical measurements. There are many games in the app stores that use marker-less AR to provide an intuitive experience. Harry Potter Wizards Unite, Jurassic world alive, AR Dragon, Knightfall AR are some of the leading examples. Other prominent use cases are Ikea Place, which allows you to place Ikea furniture in your house virtually and see how it would look like in your space. Nightsky uses AR to show the real-time locations of stars and satellites in the Space and Giphyworld, which provides a 3D drawing experience in a collaborative environment.

Persistence in Augmented Reality

All the marker-less solutions provided intuitive and novel interactions placing augmented objects in a physical world, but with a question. Will the objects I placed near my front door will always be there? Will I be able to share what I experienced through someone else’s device? It is the time when the term “persistency” comes to the stage.

Persistency in Augmented Reality defines the permanent placement of content in an augmented world. In simple terms, the user does not want to place the objects as he opens up the camera. The smartphone will automatically identify the location around you and present the already placed content. Persistent AR allows the users to create content in the virtual space and share the experience with other users. It also allowed different service providers to offer intuitive AR walkthroughs and use cases to their customers.

How does Persistent AR work?

Google has introduced Cloud Anchors, which allows developers to create AR multiplayer games which use a shared context. The first development kit offers anchors that expire after 24 hours. Apples AR Kit 2.0 released with the support for persistent tracking which does not expire. These development frameworks offered AR experiences on its solitary device environments. Microsoft Hololens introduced Azure Cloud Anchors, which uses ARKit and ARCore to provide persistent AR experiences that work cross-platform. Whatever you see in the AR world through Hololens can also be seen on either an Android or an iOS.

Shared AR experiences require the use of cloud computing. Even with ARCore and ARKit, whatever content you create in the AR space is uploaded to their non-cross-platform servers to keep track of another AR scanning. Cross-platform frameworks such as Azure Cloud Anchors removes the barrier in using one devices anchor in another platform. It uses Azure cloud servers to capture the world around you and save it securely in the cloud.

Technically, the device captures the world around you. It uses the captured photos and creates a point cloud by estimating the depths. A point cloud is a set of dots that has a position in a 3D world. Mathematically, a collection of points with different x,y and z. These points are grouped to a file and uploaded to the cloud anchor servers and provide a reference. 3D objects will be placed based on this reference. Someone else who scans the same environment now sends similar point clouds to the server. The server matches with the saved point clouds and finds the perfect match. The device can use the reference to draw the same 3D content the first person placed around. The above images explain how the creator device saves data in the AR cloud and content cloud and how the viewer device gets the references to show them. Simple yet complex!

Use cases of persistent AR

Following are some of the prominent use cases of persistent AR that can enhance the user experience intuitively.

1. Industrial applications that auto-detects the machines and place real-time usage data around it.
2. Architectural applications that showcase the results on the construction sites
3. Augmented Reality based indoor and outdoor navigation AR-based treasure hunt games
4. Working on your interior design collaboratively with the designer
5. Industrial training applications that provide step-by-step guides and instructions without a human supervisor

The applications expand with the exponential growths in different industries, which utilises new advancements in technology. Persistent AR is one of these advancements that would take over the world.