unity 弓箭抛物线

using System.Collections;
using System.Collections.Generic;
using UnityEngine;


public class ParaCurve : MonoBehaviour
{
    public Transform startPos;
    public Transform endPos;
    public Transform heightPos;
    //public float height;
    public float time;

    private float acceleration;
    private float speedX;//速度水平x分量
    private float speedZ;//速度水平z分量
    private float speedY;//垂直方向分量
    // Use this for initialization
    void Start()
    {
        float height = heightPos.position.y - startPos.position.y;
        float distanceX = endPos.position.x - startPos.position.x;
        float distanceZ = endPos.position.z - startPos.position.z;
        
        speedX = distanceX / time;
        speedZ = distanceZ / time;
        
        speedY = 4 * height / time;
        acceleration = speedY / (0.5f * time);
        transform.position = startPos.position;
        
        transform.rotation = Quaternion.LookRotation(new Vector3(speedX, speedY, speedZ),Vector3.up);
    }

    // Update is called once per frame
    void FixedUpdate()
    {
        if ((transform.position - endPos.position).magnitude > 0.1f)
        {
            speedY -= acceleration * Time.deltaTime;
            //transform.rotation = Quaternion.Euler(speedX, speedY, speedZ);
            transform.rotation = Quaternion.LookRotation(new Vector3(speedX, speedY, speedZ), Vector3.up);
            Debug.Log(transform.forward);
            Debug.LogWarning(new Vector3(speedX, speedY, speedZ).normalized);
            float speed = (new Vector3(speedX, speedY, speedZ)).magnitude;
            transform.Translate(Vector3.forward * speed * Time.deltaTime); //Vector3.forward使用局部坐标的Z方向
        }
    }

    private void DestroySelf()
    {
        GameObject.Destroy(this);
    }
}

给定初始位置，目标位置，高度，时间。

计算速度在xyz方向分量，然后通过LookRotation，箭头指向速度方向。

使用transform.Translate(Vector3.forward * speed * Time.deltaTime); 移动。

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一般是使用LookAt看向一个点，使用LookRotation沿着一个向量看过去。

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