Michael Kass, John Anderson
Oscillatory motion is ubiquitous in computer graphics,
yet existing animation techniques are ill-suited to its authoring.
We introduce a new type of spline for this
purpose, known as a ``Wiggly Spline.'' The
spline generalizes traditional piecewise cubics
when its resonance and damping are set to zero, but
creates oscillatory animation when its resonance
and damping are changed. The spline provides a
combination of direct manipulation and physical realism.
To create overlapped and propagating motion, we generate phase shifts
of the Wiggly Spline, and use these to
control appropriate degrees of freedom in a model.
The phase shifts can be created directly by procedural
techniques or through a paint-like interface. A further option is
to derive the phase shifts statistically by analyzing a
time-series of a simulation. In this case, the Wiggly
Spline makes it possible to canonicalize a simulation,
generalize it by providing frequency and damping controls
and control it through direct manipulation.
Available in SIGGRAPH 2008
Available as Pixar Technical Memo #06-06a