Recently, students from Georgia Tech and SCAD in cooperation with the Graz University of Technology showed how augmented reality can be used in gaming. ARhrrr is a zombie game created for the Tegra platform, bringing augmented reality to the world of table-top games.

Zombies game is a tabletop horror augmented reality game
The way how you play the game: use Tegra-based mobile device to capture the tabletop marker…

This title is the first time we’ve seen horror genre being deployed to the world of Augmented Reality and horror-aficionados should start pinging Georgia Tech about making this "proof of concept" into a commercial title. The effect of seeing zombies with real-world is a promising prospect not just for computer games, but may also spark the imagination of known interactive enthusiasts such as Robert Rodriguez or David Fincher.

Tracing and killing Zombies on the screen
…look out for zombies and then try to kill them. The game was captivating, but it takes some practice.

Augmented Reality was a term that was coined back in the 1980?s in contrast to the popularly known "virtual reality." Today, the term tends to mean "augmenting" the live views of the real word with added information in order to enhance the environment. Such examples exist as simple text tags, or complex 3D registered animated objects and characters. All of this was originally done via head mounted displays as opposed to cell phones. Now that we have mobile devices with cameras and large touch screens we now have mobile devices bringing augmented reality to the masses.

Augmented reality is all about the context of the objects in relation to the real world. This is one of the biggest challenges that augmented reality developer?s face. They must be able to take in the information and process it in a way that enables the user to have pertinent additional data. For example, there is the use of GPS which helps create a global relative context and then computer vision which creates an object relative context.

Some recent implementations of augmented reality include advertising in 3D magazine advertisements as well as in gaming where Sony implemented it in games for both the PS3 and PSP. There are also some iPhone and Android apps that implement augmented reality within the application to increase the information?s importance at that time.

Zombie on Tegra presentation: AR Marker
How Augmented Reality becomes a reality: a lot of 3D processing.

One of the important ways augmented reality works is the use of markers and marker tracking, which enable the more accurate placement of certain objects in the environment. In order to create ARhrrr, the work on this game was split amongst the various groups allowing them to do what they did best in order to get this game created.
When it comes to the hardware aspect of this project, Tegra platform was selected as the optimal platform for development due to power efficiency and 3D horsepower needed for tabletop games. ARhrrr combines several parts of the Tegra SoC [System-on-Chip] combining the Camera, the CPU, and GeForce 3D subsystem to increase the quality and speed of the game experience.
 
The ARhrrr pipeline is simple: the camera uses OpenMAX [multimedia acceleration API] to take in the image featuring AR Tracker. Second step is using the GPU for creating the 640×480 EGLImage Textures [OpenGL|ES 2.0 API] which are then further processed inside the GPU to downsize the images to 320×240 at 8bpp and then sent to the CPU for the AR system [NFT tracker] to make the transformation from camera to real world.
Third step is game engine calculating and sending the needed 3D game objects back to the GPU so that it creates the final rendered image combining the camera stream with the 3D game objects. As you can imagine, the amount of video processing is significant and products such as 2nd Gen Tegra are extremely important to bring this vision in commercially-attractive package.

This is also the reason why Augmented Reality has a big bridge to cross: unlike the conventional game development pipeline, in which you pre-calculate the whole world, and just wait for user input in a form of key or gamepad input, Augmented Reality games require to use the 3D pipeline twice: once for input and once for output. This increases the demands on the processing side and brings in the challenge of additional latency to the game.

By utilizing power-efficient, yet powerful hardware, developers such as these students should be able to create a commercially viable Augmented Reality projects. For now, we would like to see Zombies, even if only in 320×240 resolution.