真实感三维人脸建模及表情动画技术的研究

【作者】 张翀；

【导师】 郝重阳； 樊养余；

【作者基本信息】 西北工业大学 ， 信号与信息处理， 2004， 硕士

【摘要】 人脸是人类相互表达情感的重要部分。在计算机虚拟世界中，虚拟人脸是虚拟人表情达意的载体。人脸的造型和表情动画作为虚拟现实技术和计算机图形学中的一个分支已有30年历史了，随着影视技术、游戏娱乐、虚拟环境、远程通信、辅助医疗、刑事鉴别等方面应用的日益广泛，这一研究领域越来越受到人们的关注。假如以往的趋势为未来的发展指明了方向的话，接下来的几年对人脸造型和表情的研究将会更令人兴奋! 顺应这样的时代潮流，本论文对真实感人脸的三维建模技术及表情动画技术进行了研究。论文的工作和成果主要有： 1．在真实感三维人脸建模方面 提出了一种简单有效的由正、侧面照片重建特定人脸三维模型的新方法。采用多分辨率技术构造纹理无缝拼接图，然后把三维网格模型投影到圆柱面上并展开，根据二维图象变形技术中特征点匹配算法的数学思想，将匹配公式进行改进后应用于模型网格点的适配，在作了一定假设后推导出逆向圆柱映射的计算公式，再将适配后的柱面网格映射回去，最后进行纹理映射生成真实感的特定人脸的三维模型。 2．在人脸表情动画方面： 基于Waters的几何肌肉模型定制了一个具有17个肌肉向量的人脸模型的动画结构，用非线性插值来模拟肌肉的简单运动；同时，采用旋转变换来模拟其它的表情控制参数，例如下巴的张开角、眼帘的张开角等。从而简单而有效地实现了人脸表情。 由于人脸造型和表情动画技术研究的难度和学位论文工作的时限等原因，上述工作和成果只是局部和基础性的，但其有效性和实用价值也是可见的。更多还原

【Abstract】 Human face is the window of communication in real world, and virtual face is of the same importance in virtual world. Therefore, the construction and animation of realistic human facial models is always attractive to researchers in computer graphics, and as an identifiable area of the latter in the past 30 years, facial modeling and animation has been devoted to significant efforts with many dozens of research papers published. Its applications include such diverse fields as character animation for films and advertising, computer games, virtual reality, teleconferencing, user-interface, surgical facial planning, and criminal discrimination. Yet no perfectly realistic facial model and animation has ever been generated by computer, it remains one of the most fundermental, and as well the most difficult problem in computer graphics.The goal of the thesis work is to automate the challenging task of creating realistic facial models of individuals and generating basic expression animation.Modeling: This thesis develops a method different from traditional techniques that begins with the cylindrical projection of a generic model and its seamless global texture map using multiresolution technique, and then automatically fit the unwrapped cylindrical projected mesh to the texture map with an improved algorithm that based on 2D morphing to specify corresponding feature points(or lines). Finally, we propose a formula of inverse cylindrical projection to recompose the deformed mesh, and after the texture mapping a photo-realistic individual facial model is created.Expression animation: Based on Water’s muscle model, 17 muscle vectors are presented to simulate facial muscles’ motion by nonlinear interpolation. Meanwhile, some other parameters, for example, open of jaw and eyelids, could simply be substituted by rotation transform. Through these control parameters’ interaction, highly natural looking animations have been able to generated.The work and achievement in this thesis is just fundamental and pilot study, while it can be exploited in many applications such as natural andintelligent human-machine interfaces, virtual collaboration work, virtual learning and teaching, and so on.更多还原