Visualising 3D buildings on top of paper maps using Augmented Reality (AR).
What is Augmented Reality?
This term describes a live view of a physical, real-world environment that is augmented with computer-generated content such as 3D graphics, sound and video. Many AR applications run on mobile or tablet devices and use the built-in camera to provide the live view. Content is then superimposed on the display, hopefully enhancing the user experience.
Augmented reality vision of Regent Street
The computing power and sensors contained in modern mobile devices enable many augmented applications. The example below shows the display of the Wikitude World Browser. This uses the device location (GPS) and orientation (hardware compass) to display relevant contextual information to the user.
What is it used for?
Publishing, digital marketing and retail are the main sectors targeted by AR solution providers. Companies such as layar aim to “make the print world clickable” by adding AR content to printed material including magazines and product packaging. In the retail sector, Augment provide a way of visualising goods before you buy - now you can see what that new sofa looks like in your front room without leaving the comfort of your armchair!
How do AR applications work?
Typically, publishers upload a target image - sometimes referred to as a tracker - to a service provided by the AR vendor. The image is processed to extract a unique fingerprint and this is stored along with the publisher’s desired content. Content can range from a simple clickable web link to an interactive 3D model.
If you have the appropriate AR app running on your device and it recognises a target image through the camera, the related content is downloaded and displayed.
What have Ordnance Survey Labs built?
We decided to use a paper map as the target image and to augment it with 3D buildings. Let’s take another look at the picture shown at the start of this article:
3D sample - Sheffield
This screenshot was taken on an iPad running Augment. We loaded a 3D model of central Sheffield created by Ordnance Survey developer Guy Heathcote using sample data provided by his colleague Dave Capstick. Augment stores the 3D model and allows it to be viewed by any iOS or Android device running the app.
I’ve been following the AR progress for a while wondering what use it could be put to in our sector and here Labs has found it. The potential to revive our printed maps with AR content is immense.Rollo Home, Senior Product Manager - 3D
Augment uses a standard target image that you print out and place nearby to determine the position and orientation of the device. This enables the app to redraw the 3D model in real-time as you move the device and/or the target image. We replaced the standard target image with an A3 black and white map of central Sheffield, and matched the scale and position of the model to the building outlines on the map. This gives the illusion of 3D buildings rising out of a flat paper map.
And there’s more…
The approach described above is effective but requires the 3D model to be scaled and positioned manually on the target image. What if 3D buildings magically appeared on the paper map in the correct position and scale?
Labs built a second prototype using Qualcomm’s Vuforia, an augmented reality toolkit for software developers and Unity, a cross-platform 3D engine normally used to create games. We used the same A3 black and white map, registered it as a target image with Vuforia, created a scene containing the 3D buildings in Unity, and generated separate apps for iOS and Android. When these apps “see” the map, the 3D buildings magically appear!
This screenshot shows the scene created in Unity with the 3D buildings model positioned on the target image.
Labs are busy demonstrating the prototype to gauge interest and identify possible business applications.