Section: New Results

Spatial Motion Doodles

Figure 3. Left: A user drawing a spatial motion doodle (SMD) which is the six-dimensional trajectory of a moving frame (position and orientation), here attached to the HTC Vive controller. Right: The SMD is parsed into a string of motion tokens,allowing to recognize actions and extract the associated motion qualities. This information is transferred to an articulated character to generate an expressive 3D animation sequence.

We present a method for easily drafting expressive character animation by playing with instrumented rigid objects (see Figure 3). We parse the input 6D trajectories (position and orientation over time) – called spatial motion doodles – into sequences of actions and convert them into detailed character animations using a dataset of parameterized motion clips which are automatically fitted to the doodles in terms of global trajectory and timing. Moreover, we capture the expressiveness of user-manipulation by analyzing Laban effort qualities in the input spatial motion doodles and transferring them to the synthetic motions we generate. We validate the ease of use of our system and the expressiveness of the resulting animations through a series of user studies, showing the interest of our approach for interactive digital storytelling applications dedicated to children and non-expert users, as well as for providing fast drafting tools for animators.