Unity两点之间模拟抛物线运动

using UnityEngine;
using System.Collections;

public class parabola : MonoBehaviour {

    public float ShotSpeed = 10; // 抛出的速度
    private float time;          // A-B的时间
    public Transform pointA;     // 起点
    public Transform pointB;     // 终点
    public float g = -10;        // 重力加速度

    private Vector3 speed;       // 初速度向量
    private Vector3 Gravity;     // 重力向量
    private Vector3 currentAngle;// 当前角度
    void Start()
    {
        // 时间=距离/速度
        time = Vector3.Distance(pointA.position, pointB.position)/ShotSpeed;

        // 设置起始点位置为A
        transform.position = pointA.position;

        // 通过一个式子计算初速度
        speed = new Vector3((pointB.position.x - pointA.position.x) / time,
            (pointB.position.y - pointA.position.y) / time - 0.5f * g * time, (pointB.position.z - pointA.position.z) / time);
        // 重力初始速度为0
        Gravity = Vector3.zero;
    }
    private float dTime = 0;
    // Update is called once per frame
    void FixedUpdate()
    {
        // v=gt
        Gravity.y = g * (dTime += Time.fixedDeltaTime);

        //模拟位移
        transform.position += (speed + Gravity) * Time.fixedDeltaTime;

        // 弧度转度：Mathf.Rad2Deg
        currentAngle.x = -Mathf.Atan((speed.y + Gravity.y) / speed.z) * Mathf.Rad2Deg;

        // 设置当前角度
        transform.eulerAngles = currentAngle;
    }
}