Lerp更像是线性衰减，而SmoothDamp像是弧形衰减，两者都是由快而慢
单从视觉效果来说不觉得哪个好，个人觉得如果做相机跟随其实都可以
SmoothDamp:
transform.position = Vector3.SmoothDamp(transform.position, target.position, ref velocity, smoothTime);
Lerp:
transform.position = Vector3.Lerp(transform.position, target.position, 0.1f);
原文：http://www.cnblogs.com/hont/p/5186637.html