基于物理模型的人脸表情动画技术研究

用计算机建立人脸表情动画是当前计算机图形学研究领域的一个富有挑战性的课题，该文在总结了国内外有关该课题研究方法的基础上，提出了一种基于物理模型的人脸表情画生成算法，并依该算法计和开发了一个实际的人脸表情动画系统HUFACE。该算法将人的脸部模拟为一个弹性体，为使计算简化，又将人脸表面依其生理特性分为八个子块，脸部表情所产生的五官动作模拟为弹性体的形变，并建立相应的弹性形变模型，当脸部表情引起脸部各子块形变时，每个子块上的各点将发生位移，于是利用该模型计算这些点的位移量，由此获得表情动画中的每一帧画面，由于脸部动作由该形变模型控制，且计算简单，速度快，因此不需存储表情动画中的各个画面，提高了系统的效率，实验结果表明，由HUFACE系统生成的人脸表情真实，自然。

Facial Expression Animation Based on Physical Model

Research on the animation of the human facial expression is a very challenging topic in computer graphics. In this paper we put forward a new algorithm which is designed on the basis of a springiness physical model. According to the algorithm we design and develop a true animation system of the human facial expression, which is named HUFACE. In this system the surface of a human face is represented by an elastomer, and the whole face is subdivided into eight sections according to the human facial organ in order to simplify computation. Any expressional action on the face organ can be simulated to the springiness metamorphosing of the elastomer, and the metamorphosing model for the expressional action is also constructed in the system HUFACE. As we know that any vertex on the human face model will shift because of springiness metamorphosing, the displacements of these vertexes can be computed based on the metamorphosing model to produce every frame in the animation of the human facial expression. Since all kinds of the facial actions are controlled by the metamorphosing model and the computation is very simple, every frame of the expressional animation does not require to be saved. So this system is extremely efficient in making animations of the human facial expression. The extensive experimental results from the system show that the animation of the human facial expression produced by HUFACE is natural and realistic.