1. 刚体变换与非刚体变换

What is a non-rigid transformation?

刚体变换(rigid transformation)一般分为如下几种:

  • 平移对象,而不改变形状和大小;
  • 镜像(reflection),左右颠倒;
  • 旋转(rotation),沿着任意方向的旋转;

非刚体变换:描述的是对几何物体大小而非形状的改变。

也即:

  • 刚体变换:shift or reflection(A rigid transformation preserves all distances and angle measures (and depending on your taste, orientation too),刚体变换能够继续保持物体中各点的距离和角度)
  • 非刚体变换:stretching or shrinking