Sketch-Based Controllers for Blendshape Facial Animation

Abstract

The blendshape approach is a widely used technique to generate realistic facial animation. However, creating blendshape facial animations using traditional weight editing tools requires either memorizing the function of a large number of parameters, or a trial-and-error search in a high-dimensional space. Direct manipulation interfaces address this problem, allowing the artist to directly move and pin manipulators placed on the surface of the face. Placing manipulators is an open-ended and slightly unnatural task for artists however. In this paper we present a sketch-based approach to this problem, inspired by artists' brush painting on canvas. In this approach the artist simply sketches directly onto the 3D model the positions of the manipulators that they feel are needed to produce particular facial expression. The manipulators activate the blendshapes in the model and allow the user to interactively create the desired facial poses by a dragging operation in screen coordinates. Our hybrid method can be used with any blendshape facial model and allows producing expeditious manipulation in an intuitive way.