That means a vector that is at every point of the curve perpendicular to the curve and has length one.
也就是，曲线每一点上,垂直于曲线，模长为1的向量。
2
This blade has a gentle, sloping convex curve to the point versus the concave curve of the clip blade.
相对于回形刀刃的凹曲线而言，这种刀刃具有一条延伸到刀尖的、温和的凸斜率曲线。
3
A quadratic bezier curve has a start and an end point (blue dots) and just one control point (red dot) while a cubic bezier curve USES two control points.