Modeling continuous shape change for facial animation

The movement of landmarks on the human face can be recorded in 3D using motion capture equipment. We describe methods for the analysis of data collected on groups of subjects with a view to describing and assessing the differences between the facial motions of those groups. We focus on the smile motion in particular. The methods presented can be used more generally for continuous shape change data. We introduce a novel parameterization of shape change that allows the parsimonious description of facial motion. We allow for a distinction between static facial shape and dynamic facial motion. We describe statistical methods for modeling differences in facial motion including a comparison of mean motions, principal components for describing the variation in motion and linear models for describing the effects of predictors.