D. Uhler, K. Mehta, and J.L. Wong (Eds.): MobiCase 2012, LNICST 110, pp. 100–114, 2013. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013 Towards Multimodal 3D Tabletop Interaction Using Sensor Equipped Mobile Devices Florian Klompmaker 1 , Karsten Nebe 2 , and Julien Eschenlohr 1 1 University of Paderborn, C-LAB, Fürstenallee 11, 33647 Paderborn, Germany florian.klompmaker@c-lab.de, eschenlohr@googlemail.com 2 Rhine-Waal University of Applied Sciences, Südstraße 8, 47475 Kamp-Lintfort, Germany Karsten.Nebe@hochschule-rhein-waal.de Abstract. Interactive tabletops have been proven to be very suitable setups for collaborative work especially in combination with mobile devices. Further on, many application scenarios require the visualization of 3D data. Therefore we present multimodal 3D interaction techniques for tabletops that allow simultaneous control of six degrees of freedom using sensor equipped mobile devices. In two early user studies we compared multitouch, tangible interaction and sensor equipped smartphones in order to start a User Centered Design process. We got important results regarding effectiveness, intuitiveness and user experience. Most notably we figured out that mobile devices equipped with acceleration sensors are very suitable for 3D rotation tasks. Keywords: Tabletop, Multitouch, 3D User Interface, Mobile 3D Interaction, Smartphone, User Centered Design. 1 Introduction Since the first Microsoft Surface appeared on the market in 2008, tabletop devices got quite famous and a lot of effort has been spent in technical improvements and the development of new interaction paradigms. It has been shown that these devices are suitable for special use cases like rapid prototyping [1], architecture and city / landscape planning [2,3], disaster management [4], collaborative document management [5] as well as training and learning [6,7]. In general terms it has been shown that tabletop devices in combination with Natural User Interfaces can dramatically enhance collaborative scenarios. One reason for this is the size of the display. It allows every participant in a collaborative setting to see WHO is currently doing WHAT. This so-called awareness of others [8,9] can’t be found in classical Computer Supported Cooperative Work scenarios if multiple private devices are used instead of a large shared display. When developing collaborative applications for tabletop devices designers and programmers have to consider several aspects like the orientation of graphical objects [10], private and public spaces [11], security issues and group dynamics [12]. We have shown that User Centered Design (UCD) is a