基于关键视频帧跟踪数据的三维虚拟人动画

3D Virtual Human Animation Based on Captured Motion Data in Key Video Frames

根据VRML中H-anim标准对虚拟人进行几何建模。在虚拟人文件导入过程中,利用有限状态机(FSM)对文件进行解释,为便于虚拟人的显示及控制,以树型数据结构表示虚拟人几何数据,完成了一个用于三维虚拟人动画的开发包VHASDK。建立了人体运动中世界坐标系及各关节点的局部坐标系,利用逆运动学计算出关键帧中人体各关节点相对于初始状态下的位移向量及旋转轴角,在虚拟人的动画过程中对关节点旋转采用四元数球形线性插值法进行平滑处理。最后完成了一个原型系统,采用多个虚拟人及多种人体运动方式进行了系统验证。

The virtual human geometry was modeled according to H-anita standard defined in VRML. In the process of importing virtual human files, FSM （Finite State Machine） was used to parse them. Furthermore, a tree structure for modeling the geometry hierarchy relationship within virtual human was developed in the purpose of making virtual human display and control more convenience. Based on these improvements, a SDK named VHA was designed for the animation of virtual human. Additionally, a world coordinate system and local coordinate systems of human joints were established, based on which, transform vectors, rotation vectors and rotation angles between joints coordinates in original state and current state could be calculated using IK（inverse kinematics）. Then, slerp method was used to smooth the joints rotation during the virtual human animation period. Finally, a prototype system was designed and developed to verify this algorithm, in which some virtual humans and various human motion styles were used.