3D facial modeling is an important research topic in computer
graphics, mainly due to its wide applications in game and
film industries. Recent progress in 3D facial modeling research
advocates the importance of the modeling of fine-scale wrinkles,
since it can reinforce the perception of the complex emotions
in the facial performance [1,2]. For example, the frown lines are
indispensable clues of unpleasant or disapproval emotions.