反向运动学(Inverse Kinematics -IK)是计算机动画设计中的一个基本问题。本文设计了一个可视化IK编辑系统，为用户提供了方便直观的动画设计工具。采用bvh文件的人体骨骼数据存储格式，其中的关键是关节角度使用欧拉角的形式存储。建立与之相应的分层的多叉树数据结构，各节点表示人体骨骼中的关节。运用MFC和OpenGL等编程工具，绘制出人体骨架的3D模型，实现 bvh 动画的播放以及人体姿态IK编辑。IK编辑功能主要采取以下三种算法:循环坐标下降 (CCD)，雅可比矩阵转置，最小阻尼二乘法。算法结束后利用绕任意轴的旋转分解为分别绕z、x、y轴旋转的欧拉角，保存为bvh文件的一个关键帧。最后可以通过对关键帧的插值，生成新的bvh动画文件。文中对于三种算法的实验结果进行了比较和分析，指出了它们的优缺点。

Inverse Kinematics is a fundamental problem of computer animation design. This paper design a visual IK edit system, providing user a convenient and intuitionistic tool for animation design. To use the skeleton data storage format of bvh file, the key point is to store angle of joints in Euler forms. Build a corresponding hierarchy multiple branch tree data structure, of which every node denote skeleton joint. Make use of MFC and OpenGL programing tools to draw skeleton 3D model, and implement bvh animation playing and skeleton pose editing. IK edit function mainly base on three methods below: Cyclic Coordinate Descent, Jacobian Transpose, and Damped Least Squares. When finishing the method, decompose rotation around arbitrary axis into rotation around z, x, y axis of Euler and store in a bvh key frame. Finally, slerp between the key frames to create a new bvh animation file. The paper compares and analyzes the experiment result of three methods, indicating the merit and shortcoming of the methods.