SIGGRAPH Shows Mobile AR and Laser Plasma

Under the title Augmented Reality Game, a team from the universities of Canterbury and Linköping presented an entertainment system for mobile devices. Software continuously analyses a camera phone’s image and adds display objects as if they were part of the physical scene. Mark Billinghurst, David Sickinger, Anders Henrysson and Mark Ollila demonstrated the concept with a two-player tennis game.

The players sit opposite each other with a card carrying black-and-white symbols on the table. Each phone analyses the card, then displays a tennis court whose orientation and perspective match the real table and tracking marker.

Moving a handset to the right moves the corresponding racket on the virtual court. The two phones exchange ball coordinates and handset movement over Bluetooth. OpenGL ES, the mobile-device variant of OpenGL, renders the court.

#Tennis

A more futuristic exhibit was a true 3D display based on laser plasma. Its demonstration produced small luminous points suspended in open space and arranged into geometric forms. Calling it a display was generous, but the technique was unusual.

A focused laser heats air at its focal point until plasma forms and emits a bright white light with a loud report similar to a welding spark. Air serves as the projection medium, allowing the method to operate without a screen. One suggested use was writing advertising messages into the night sky, although the required laser would be powerful enough to raise obvious safety concerns.

The three staff members wore laser-protection glasses during demonstrations, while spectators did not receive any. The prototype projected roughly 60 points at once, enough to suggest a 3D form but far short of demanding display applications. The technology remained at a very early experimental stage.