Moving images are omnipresent in cinema, television, computer
games and online entertainment. Digital media such as text,
images and film are nowadays produced by a diverse crowd of
authors, ranging from beginners and laymen to professionals. Yet
animation is still seen by most people as a highly sophisticated
process that only experts can master, using complex interfaces
and expensive equipment. However, consumer motion capture
technology has recently enabled and created a mass-market for
easy-to-use animation tools: computer games. In contrast to most
professional animation tools, recent games employ full-body interaction
for instance via Kinect, allowing users to control a virtual
character instantaneously through their body. This trend is feeding
back into the area of the ‘‘experts’’, with researchers investigating
time-efficient interfaces for computer puppetry using the Kinect
(e.g. [61,55]. Computer animation is currently seeing an influx of
ideas coming from the world of easy-to-use game interface made
for players with no prior training. Game designers in turn are
informed by design knowledge and methods developed over
decades of research in human–computer interaction (HCI).
It is thus time that computer animation be approached from an
HCI perspective. This could aid describing and analyzing the vast
spectrum of animation techniques ranging from very intuitive puppetry
interfaces for computer games to highly sophisticated control
in advanced animation tools. Our goal is to understand
principles that underlie human–machine interactions in computer
animation. With new ways of thinking about interactions with
continuous visual media and a thorough investigation of new animation
interfaces on a theoretical foundation, motion design interfaces
can be made more beginner and expert friendly.
This can be achieved by embedding computer animation methods
and interfaces in an HCI context. Trends in motion design
interfaces can be connected with discussions on next generation
interfaces in HCI. Theoretical frameworks can aid us in tackling
the concrete user interface issues by a profound analysis, which
can aid the process of designing new mechanisms for more natural
and intuitive means of motion creation and editing.
This article approaches this goal in three main steps. We will
first review related work from computer graphics, human computer
interaction and entertainment computing from a user- and interface-
centric perspective with a focus on methods, mappings and
metaphors. In the second step we construct a design space for interfaces
that deal with spatiotemporal media. In the third step, the
utility of this conceptual framework is illustrated by applying it in
designing a multi-touch interactive animation system.