基于NURBS自由变形的腿部运动建模方法

如何建立人体各部分的数字模型是生物医学和计算机工程界较为关心的研究课题。利用基于ＮＵＲＢＳ的自由变形方法模拟膝关节变曲和股肉变形，并在二阶Ｂ样条基函数的基础上，依据关节的解剖结构，推导出了符合膝关节运动特点和肌肉特性的计算公式。

A LEG MOTION MODELING METHOD BASED ON NURBS FREE-FORM DEFORMATION

Human body modeling is an important research work in the fields of biomedicine andcomputer engineering. On the basis of NURBS FFD (free-form deformation), a motion modelingmethod is discussed to simulate the bend of human leg and corresponding de formations of muscles. Generally, FFD uses a trivariate tensor product spline to transmit deformations, and it is feasible to choose only two-order B-spline basis function in this case. According to the anatomic structure of joints, the simulation formulas are presented, and they coincide with the motion characteristics of knee joint and muscles. In the final experiment, a proper selected lattice space and these formulas yield a good visual effect of simulation. Compared with the method of curved patches, this method is simple and efficient. The formulas can be easily applied to simulate the motion of other joints.