CMAR

Recently, mobile phones have developed in the same manner as personal computers. With integrated cameras, fast processors, full color displays, possibilities for wireless communication and even dedicated 3D graphics chips the mobile phones have transformed into ideal mobile augmented reality devices. Anders Henrysson, a PhD student at Linköping university ported ARToolKit to the symbian OS and developed an augmented reality (AR) application called ARTennis. ARTennis is a face to face collaborative AR game where two players plays tennis against each other. The players can see a virtual tennis court overlaid on the real marker between them. The mobile phones are used as rackets and the players interact by physically moving their phones to hit the virtual ball across the net. This application is limited to only two users and does not involve any object manipulation except hitting the ball.

Our diploma work was to extend Anders Henrysson’s work and to share complex scenes between multiple mobile devices in an augmented reality environment. The result of our diploma work is called CMAR, which is a platform for interactive collaborative face to face augmented reality using a distributed scene graph on mobile phones. The results of individual actions are viewed on the screen in real-time on every connected phone. We show how multiple collaborators can use consumer phones to furnish a room together in an augmented reality environment.

In CMAR it is possible for up to eight persons to collaborate and manipulate objects in the same scene. The data is distributed through a Bluetooth network and one of the connected phones acts as a server. It is also possible to connect a PC client to the network for a high resolution overview. The software needed for this is a part of the platform and is called CMAR ViSION. This computer can be connected to a projector or a big screen display.

As a demo for our platform a furnishing application was created. In this application users can use their mobile phones to move around virtual furniture on a real apartment plan. In order to be able to import models into our system a model converter and simplifier was created, which is a extern PC application called CMAR ModConverter. We also developed our own model format, which was more suitable for our purposes. For more details please read the report.

This platform is totally independent of a PC server and makes it therefore very portable. Our vision was to create a cheap easily accessible system build on existing technology that novel people can use. The CMAR platform may be used in following application areas: architectural planning, entertainment (games), education and military planning.

Screenshots from CMAR ViSION in the top and from four mobile phones below.

A simple example of AR on mobile phones.

Example of a CMAR network.

CMAR ViSION running on a notebook connected to a 50" plasma.