在三维空间中，利用抛物线公式计算弹道，得到一个发射初速度，让导弹打击到指定地点

通过以下两个脚本实现。工具脚本计算弹道，Missile脚本每帧更新导弹位置

PhysicsUtil.cs

using UnityEngine;/// 
 物理计算工具/// 
     
      ZhangYu 2018-05-10
     /// 
public static class PhysicsUtil {    /**findInitialVelocity     * Finds the initial velocity of a projectile given the initial positions and some offsets     * @param Vector3 startPosition - the starting position of the projectile     * @param Vector3 finalPosition - the position that we want to hit     * @param float maxHeightOffset (default=0.6f) - the amount we want to add to the height for short range shots. We need enough clearance so the     * ball will be able to get over the rim before dropping into the target position     * @param float rangeOffset (default=0.11f) - the amount to add to the range to increase the chances that the ball will go through the rim     * @return Vector3 - the initial velocity of the ball to make it hit the target under the current gravity force.     *      *      Vector3 tt = findInitialVelocity (gameObject.transform.position, target.transform.position);            Rigidbody rigidbody = gameObject.GetComponent
    
      ();            Debug.Log (tt);            rigidbody.AddForce(tt*rigidbody.mass,ForceMode.Impulse);     */    public static Vector3 GetParabolaInitVelocity(Vector3 from, Vector3 to, float gravity = 9.8f, float heightOff = 0.0f, float rangeOff = 0.11f) {        // get our return value ready. Default to (0f, 0f, 0f)        Vector3 newVel = new Vector3();        // Find the direction vector without the y-component        /// /找到未经y分量的方向矢量//        Vector3 direction = new Vector3(to.x, 0f, to.z) - new Vector3(from.x, 0f, from.z);        // Find the distance between the two points (without the y-component)        //发现这两个点之间的距离（不y分量）//        float range = direction.magnitude;        // Add a little bit to the range so that the ball is aiming at hitting the back of the rim.        // Back of the rim shots have a better chance of going in.        // This accounts for any rounding errors that might make a shot miss (when we don't want it to).        range += rangeOff;        // Find unit direction of motion without the y component        Vector3 unitDirection = direction.normalized;        // Find the max height        // Start at a reasonable height above the hoop, so short range shots will have enough clearance to go in the basket        // without hitting the front of the rim on the way up or down.        float maxYPos = to.y + heightOff;        // check if the range is far enough away where the shot may have flattened out enough to hit the front of the rim        // if it has, switch the height to match a 45 degree launch angle        //if (range / 2f > maxYPos)        //  maxYPos = range / 2f;        if (maxYPos < from.y)            maxYPos = from.y;        // find the initial velocity in y direction        /// /发现在y方向上的初始速度//        float ft;        ft = -2.0f * gravity * (maxYPos - from.y);        if (ft < 0) ft = 0f;        newVel.y = Mathf.Sqrt(ft);        // find the total time by adding up the parts of the trajectory        // time to reach the max        //发现的总时间加起来的轨迹的各部分//        //时间达到最大//        ft = -2.0f * (maxYPos - from.y) / gravity;        if (ft < 0)            ft = 0f;        float timeToMax = Mathf.Sqrt(ft);        // time to return to y-target        //时间返回到y轴的目标//        ft = -2.0f * (maxYPos - to.y) / gravity;        if (ft < 0)            ft = 0f;        float timeToTargetY = Mathf.Sqrt(ft);        // add them up to find the total flight time        //把它们加起来找到的总飞行时间//        float totalFlightTime;        totalFlightTime = timeToMax + timeToTargetY;        // find the magnitude of the initial velocity in the xz direction        /// /查找的初始速度的大小在xz方向//        float horizontalVelocityMagnitude = range / totalFlightTime;        // use the unit direction to find the x and z components of initial velocity        //使用该单元的方向寻找初始速度的x和z分量//        newVel.x = horizontalVelocityMagnitude * unitDirection.x;        newVel.z = horizontalVelocityMagnitude * unitDirection.z;        return newVel;    }    /// 
     
 计算抛物线物体在下一帧的位置 
    /// 
     初始位置    /// 
     移动速度    /// 
     重力加速度    /// 
     飞行时间    /// 
         public static Vector3 GetParabolaNextPosition(Vector3 position, Vector3 velocity, float gravity, float time) {        velocity.y += gravity * time;        return position + velocity * time;    }}
    

Missile.cs

using UnityEngine;/// 
/// 抛物线导弹/// 
     
      计算弹道和转向
     /// 
     
      ZhangYu 2019-02-27
     /// 
public class Missile : MonoBehaviour {    public Transform target;        // 目标    public float hight = 16f;       // 抛物线高度    public float gravity = -9.8f;   // 重力加速度    private Vector3 position;       // 我的位置    private Vector3 dest;           // 目标位置    private Vector3 velocity;       // 运动速度    private float time = 0;         // 运动时间    private void Start() {        dest = target.position;        position = transform.position;        velocity = PhysicsUtil.GetParabolaInitVelocity(position, dest, gravity, hight, 0);        transform.LookAt(PhysicsUtil.GetParabolaNextPosition(position, velocity, gravity, Time.deltaTime));    }    private void Update() {        // 计算位移        float deltaTime = Time.deltaTime;        position = PhysicsUtil.GetParabolaNextPosition(position, velocity, gravity, deltaTime);        transform.position = position;        time += deltaTime;        velocity.y += gravity * deltaTime;        // 计算转向        transform.LookAt(PhysicsUtil.GetParabolaNextPosition(position, velocity, gravity, deltaTime));        // 简单模拟一下碰撞检测        if (position.y <= dest.y) enabled = false;    }}