Abstract

Augmented reality offers new and exciting ways to interact with our surroundings. This phenomenon is being adopted by museums world wide, and for good reason. Visitors of these venues have reported positive experiences when the exhibitions are enhanced with augmented reality technology.

During this project we explored one possible usage of AR in a museum by developing a projective AR application in cooperation with the "Museum für Abgüsse klassischer Bilderwerke" in Munich (http://www.abgussmuseum.de/). It allows visitors to interact with the Tombstone of Xanthippos by painting it on a tablet and projects this coloring process onto the actual exhibit in real-time to be shared with the other attendants. This offers a save way to interact with the artwork without physically touching or altering it, while still giving the impression of retrieved color. Furthermore it allows for artistic freedom and dynamic modification of the paint. The application additionally includes historical background information on the tombstone and the pigments used for painting in ancient Greece.

Our goal was to examine whether the usage of projective AR in this way is improving the visitors experience during an exhibition. Another major focus were easy and intuitive controls for the application. Firstly, to reach visitors of all ages and technological backgrounds. Secondly, since many of the visitors will only spend a short time with this feature during an exhibition and have no time to learn a more complicated interface.

All testing during production and the user study were performed using a scaled 3D printed replica of the original tombstone generated through Autodesks ReCap Photo. For the implementation we used Unity game engine.

Project Setup and Features

Since the object provided by the museum, the Tombstone of Xanthippos, is a rather flat stele, with all important features on one site, it is perfect for a single projector setup. This allows for a focus on other aspects of this project. The users point of interaction is an app running on a tablet, as a touchscreen allows for the most intuitive drawing experience. Since most tablets can not be directly connected to the projector a intermediary computer is needed. For the communication between this computer and the tablet we use Ubi-Interact.

The app allows for three main ways to interact with the exhibition object. The first and arguably most important of these is the drawing screen. Here the user can draw on the surface of a 3D model of the stele. This can be done with one of two provided tools. A brush tool that draws lines of variable sizes, similar to any normal paint program, and a fill tool, with which users can color predefined areas with a single click. The drawing process is projected live onto the object.

Another way of interaction is the gallery. This is also the default state of the app when no visitor is using it. It displays all the previously created drawings and switches between them every 30 seconds. The drawing currently displayed is also projected onto the stele.

Lastly there is the info menu, which gives visitors additional historic background information about different parts of the tombstone. The user can select a part and read an informational text about it. Meanwhile, the corresponding part is highlighted on the real object. This is particularly of use when the part on the original object is damaged - as for example the name "Xanthippos" engraved on top of the stele - and can thus be reconstructed. All historic information was provided by the museum.

Conclusion

Gallery and Impressions

Paper and Presentation Slides