Vector3.Slerp 球形插值

using UnityEngine;
using System.Collections;

public class example : MonoBehaviour {
	public Transform sunrise;
	public Transform sunset;
	void Update() {
		Vector3 center = sunrise.position + sunset.position * 0.5F;
		center -= new Vector3(0, 1, 0);
		Vector3 riseRelCenter = sunrise.position - center;
		Vector3 setRelCenter = sunset.position - center;
		transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, Time.time);
		transform.position += center;
	}
}

// Animates the position in an arc between sunrise and sunset.
//在日出和日落之间动画弧线
var sunrise : Transform;
var sunset : Transform;

function Update () {
	// The center of the arc
	//弧线的中心
	var center = (sunrise.position + sunset.position) * 0.5;
	// move the center a bit downwards to make the arc vertical
	//向下移动中心，垂直于弧线
	center -= Vector3(0,1,0);

	// Interpolate over the arc relative to center
	//相对于中心在弧线上插值
	var riseRelCenter = sunrise.position - center;
	var setRelCenter = sunset.position - center;
	transform.position = Vector3.Slerp(riseRelCenter, setRelCenter, Time.time);
	transform.position += center;
}