idAnimate: A General-Purpose Animation Sketching Tool for Multi-Touch Devices

Creating animations is a complex activity that often requires an expert, especially if results need to be obtained under time pressure. As animations are potentially relevant in many different contexts, it is interesting to allow more people to use them for communicating ideas about time-varying phenomena. Multi-touch devices create opportunities to redesign existing applications and user interfaces, and new classes of animation authoring tools that use gestural interaction have therefore started to appear. Most of them focus on specific applications, such as cartoon and puppet animation. In this paper, we present idAnimate, a low-fidelity general-purpose animation authoring system for sketching animations on multi-touch devices. With idAnimate, the user can intuitively manipulate objects with his fingers, while the system records the trajectories and transformations and uses them to build animations. Next to describing idAnimate, we also present a comparison study with an alternative state-ofthe-art animation-sketching tool, called K-Sketch. The experimental results lead us to conclude that idAnimate is easier to understand and learn, and that it is significantly faster for certain types of scenarios, at the cost of a reduced precision and detail in the outcome. Keywords-Animation; Multi-Touch; Creativity-SupportTools; User-Study; Design