The Invisible Train

The Invisible Train

The Invisible Train is the first real multi-user Augmented Reality application for handheld devices (PDAs). Unlike other projects, in which wearable devices were merely used as thin-clients, while powerful (PC-based) servers performed a majority of the computations (such as graphics rendering), our software runs independently on off-the-shelf PDAs - eliminating the need for an expensive infractructure.

Why Handheld Augmented Reality?

Augmented Reality (AR) can naturally complement mobile computing on wearable devices by providing an intuitive interface to a three-dimensional information space embedded within physical reality. However, prior work on mobile Augmented Reality has almost exclusively been undertaken with traditional "backpack"-systems that consist of a notebook computer, an HMD, cameras and additional supporting hardware. Although these systems work well within a constrained laboratory environment, they fail to fulfill several usability criteria to be rapidly deployed to inexperienced users, as they are expensive, cumbersome and require high level of expertise.

Since the early experiments in Mobile Augmented Reality, a variety of highly portable consumer devices with versatile computing capabilities has emerged. We believe that handheld computers, mobile phones and personal digital assistants have the potential to introduce Augmented Reality to large audiences outside of a constrained laboratory environment. The relative affordability of devices that are capable of running our software framework opens up new possibilities for experimenting with massively multi-user application scenarios - thereby bringing us closer to the goal of "AR anytime, anywhere".

Handheld Augmented Reality

Mobile systems are one of the latest hot topics in augmented reality research. There has been a lot of success in creating mobile setups using mobile personal computer hardware such as notebooks. The advantage of those approaches is that mostly the same hard- and software can be used as for traditional setups. The disadvantage is that those setups are not mobile in a sense that a user would like to use them. In the Handheld AR project we focus on realising augmented reality on off-the-shelf mobile devices.