详解Victor3.Lerp

完整的写法：public static Vector3 Lerp(Vector3 a,Vector3 b,float t);

首先看一下API是怎么说的：

Linearly interpolates between two vectors. Interpolates between the vectors a and b by the interpolant t. The parameter t is clamped to the range [0, 1]. This is most commonly used to find a point some fraction of the way along a line between two endpoints (e.g.