圆弧路径法，一种新的多边形变形方法

二维形状变形技术在二维角色动画、模式匹配、几何造型、虚拟现实、工业模拟、科学计算可视化等领域有着重要的应用。本文提出了一种顶点路径圆弧法的二维形状变形新方法。该算法通过控制关键帧多边形顶点按照一条特殊的圆弧曲线路径进行运动，实现二维形状变形。通过许多实例的测试表明，该算法效果良好：不仅可以保持首末关键帧形状的共同特征，而且中间插值形状变化自然平滑。同时，我们的方法易于用户交互控制；容易推广到高维情形；计算量较小、能达到系统实时的要求。

Circular arc locus method, a new 2D polygon blending algorithm

2D shape blending or morphing is the process of continuously transforming one polygon into another, which is widely applied in 2D character animation, pattern matching, geometric modeling, virtual reality technologies and simulation, etc. This paper presents a new 2D shape blending algorithm based on the vertex circular arc path. After controlling the vertex locus preferably, user controls the morph by specifying the type of vertex correspondence as well as the feature correspondence between the source and target shapes. Some techniques are also provided to control the vertex path during the morphing process. The amount of user input required when producing a morph is directly proportional to the amount of controls the user wishes to impose on the process. The morphing process can also be generated automatically by the system. This approach is totally geometry based and is easy and fast enough in fully interactive time. This paper also presents experimental results showing the applicability, flexibility, and expandability of this approach. The results are satisfactory, which show that the two polygons can be blended as user prescribed whilst keeping the feature correspondence and feature preservation.