摘要： 虚拟膝关节手术过程中要求对膝关节3D几何模型进行实时的大范围形变，而形变的特点，包括总体轮廓、细节保持、实时性、平滑性以及拓扑性等都影响到它的真实感。针对膝关节3D模型得到了一种新的形变方法，根据模型的横截面构建出模型的骨架，并利用柱坐标的变换来实现大范围形变，使形变能保持良好的局部细节特征，算法能满足虚拟手术的实时性和真实感的要求。该方法也能推广应用于其他类似的关节弯曲运动的实时变形。

关键词: 虚拟膝关节手术, 3D几何模型, 大范围形变, 骨架, 柱坐标

Abstract: A real-time large scale deformation for the 3D geometry model of the knee joint is required in the virtual knee joint surgery. The quality of the deformation, including the outline, the detail, the degree of smoothness, the topological characteristics and so on, has an evidence effect on reality. Towards the 3D model of the knee joint, a new deformation method is established. It can perform deformation by building the skeleton of the model based on the cross section of the mesh, and using the transformation of the cylindrical coordinates. The geometry character of the model is correctly preserved. This method can satisfy the demand of real-time and reality in the virtual surgery. This method can also be applied to other bend deformations on joints.

Key words: virtual knee joint surgery, 3D geometry model, large scale deformation, skeleton, cylindrical coordinates

中图分类号: 

• TP391.41