In this paper we describe a system to project virtual characters that shall live with us in the same environment. In order to project the characters' visual representations onto room surfaces we use a controllable projector.

A relatively new form of Augmented Reality (AR), projector based AR using stationary projectors, makes use of rotatable projection devices to augment objects. However, the range of such systems is limited. In order to exceed these limits, we introduced the ability to switch the projection of the augmentation between several projection systems. This way the system with the best position in relation to the object to be augmented can be selected to do the projection, and thus the quality of the augmentation can be optimized. A crucial part of this process is the estimation of the achievable projection quality of all projection systems, which may also be dependent on the type of application.

Augmenting or annotating physical objects using steerable video projector and camera combinations works well in the range of the projection system. However, since these systems are usually mounted in fixed locations, users have to stay within a certain radius around that location. By using several of these AR-Projection systems, we can make the application roam these systems and thus follow the user beyond these limits. Using this method, we furthermore remove the need to hold the augmented objects in a suitable direction towards the projector and can reduce the possibility of shadowing the projection by the user. We describe an architecture based on our 'Projected Applications' which coordinates the systems used to project the augmentations and keeps the projected applications' states in sync between the projection systems.

In this paper, we propose a new way of augmenting our environment with information without making the user carry any devices. We propose the use of video projection to display the augmentation on the objects directly. We use a projector that can be rotated and in other ways controlled remotely by a computer, to follow objects carrying a marker. The main contribution of this paper is a system that keeps the augmentation displayed in the correct place while the object or the projector moves. We describe the hardware and software design of our system, the way certain functions such as following the marker or keeping it in focus are implemented and how to calibrate the multitude of parameters of all the subsystems.

The Virtual Table presents stereoscopic graphics to usually a single user in a workbench like setting. The paper describes the pen and paper paradigm, which besides being an easy to use user interface for sketching or similar tasks, provides the possibility for several users to work on the Virtual Table at the same time. They are not only able to move objects or to sketch on them independently, but they even can view the objects they are working on in a stereoscopic mode with the correct perspective due to individual head tracking. This way the Virtual Table becomes usable for groups of users, too. At the same time the pen and paper paradigm in combination with two handed input creates a very intuitive user interface for drawing, sketching or painting tasks.