Free-form Deformation Algorithm Avatar Generation System

With the advent of 3D epoch in computer science, the rapid advance of calculating ability and the flourishing development of networks application, 3D face modeling and animation have become one of the hottest topics in computer graphics research field. Nowadays, 3D modeling and computer animation have got widely applications, such as entertainment industry, man-machine interaction, multimedia, communication etc. The third dimension head portrait has been applied to correlative areas, for examples, movie special effects, virtual conference call, internet increment business, mobile internet increment business and software operation interface etc.In the fields of geometric modeling and computer animation, the deformation technology is an important tool. The deformation technology can simulate many deformations such as the deformation of flexible objects, which is unable to achieve by traditional modeling and computer animation method, so it attracts people's extensive interest and recognition.This thesis studies the Free Form deformation algorithm and its application in three dimensional face modeling and animation. It is well known that 2D Dirichlet free form deformation algorithm is an extensively used algorithm. This algorithm allows the users design the control frame freely. Compared with other algorithms, it abandons the limitation of topological structure among the control points and uses Sibson local coordinate system, so it is more flexible and universal. So far, the research works on Dirichlet method are mainly centralized in two-dimensional space. This thesis extends this algorithm from two-dimensional space to three-dimensional (3D) space. The realization of the method in 3D space is given in details. This extension is not a simple work at all. The core of Dirichlet free form deformation is in the calculating of the Sibson local coordinate value of the control point, i.e. the influence on the object point by Sibson neighbors. In two-dimensional space, the Sibson coordinate value is the ratio between the areas of Voronoi cells, and the Voronoi cell is made up of the perpendicular bisector of triangles. But in 3D space, the Sibson coordinate value is the ratio between the volumes of Voronoi cells, and the Voronoi cell is made up of the perpendicular face...