A new modeling method for objects with branching problem using non-uniform B-spline

In many applications, objects are reconstructed from cross-sections for visualization, finite element and dynamic analysis. Although cross-section of an object may contain multiple contours, a few papers have dealt with branching problem. Moreover ends of branches are described flatly. In this paper, as a basic study for dynamic analysis of a human knee joint, we present a new modeling method which proposes a data-set for solving branching problem and handling convex-end-condition of branches. We select an initial standard point from lowest slice and decide a nearest standard point of the next slice and the next, in turns. Based on standard points, we complete the data-set by applying contour alignment. For 3D reconstruction, the surface is approximated by bicubic non-uniform B-spline surface fitting. This method provides the smooth surface model with C-2 continuity and describes the convexity of ends of branches.