Unity 中的 Raycast 2D 弹跳？

Question

我是 Raycasting 的新手，所以我可能会以不好的方式处理这个问题，但我会向外发送光线投射到游戏对象所面对的方向，从它击中的第一个对象反弹并在消失前走一小段距离.

据我所知，Unity 中没有用于反射光线投射的内置函数，所以我一直在尝试生成另一个光线投射，但我的运气并不好。到目前为止，这是我所拥有的：

public Gameobject firePoint; // I have an object attached to my main object that I use as a point of origin

void DrawLazer()
{
    Vector2 origin = new Vector2(firePoint.transform.position.x, firePoint.transform.position.y);
 
        Vector2 direction = transform.TransformDirection(Vector2.up);
 
        RaycastHit2D hit = Physics2D.Raycast(origin, direction, 10f);
        Debug.DrawLine(origin, direction *10000, Color.black);
        if (hit)
        {
            Debug.Log("Hit: " + hit.collider.name);
            var whatWeHit = new Vector2(hit.transform.position.x, hit.transform.position.y);
            var offset = whatWeHit + hit.point;
            offset.y = 0;
 
            RaycastHit2D hit2 = Physics2D.Raycast(offset, Vector3.Reflect(direction, hit.normal) * -10000);
 
            if (hit2)
            {              
                Debug.DrawLine(offset, -Vector3.Reflect(direction, hit.normal) * -10000);
            }
        }
}

我调用 DrawLaxer();正在更新中。

当前的脚本能够生成第二次光线投射，但是正如您所见，第一次光线投射在击中某物时仍然不会停止，更重要的是，虽然该解决方案在击中平面物体时效果很好水平面。但是，如果它在垂直或对角平面上撞击物体，则会对错误的轴应用多个计算：

任何帮助将不胜感激。

Answer 1

这是一个使用 Vector2.Reflect 和 SphereCast 的完整示例单体行为。

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

public class ReflectionExample : MonoBehaviour
{

    public GameObject firePoint;

    // Start is called before the first frame update
    void Start()
    {

    }

    // Update is called once per frame
    void Update()
    {
        DrawPredictionDisplay();
    }


    private void DrawPredictionDisplay()
    {

        Vector2 origin = firePoint.transform.position; //unity has a built in type converter that converts vector3 to vector2 by dropping the z component

        Vector2 direction = firePoint.transform.up;

        float radius = 1.0f;

        RaycastHit2D distanceCheck = Physics2D.Raycast(origin, direction);

        RaycastHit2D hit = Physics2D.CircleCast(origin, radius, direction);


        Debug.DrawLine(origin, direction * 10000, UnityEngine.Color.black);
        DrawCircle(origin, 1.0f, UnityEngine.Color.black);

        if (hit)
        {

            origin = hit.point + (hit.normal * radius);
            direction = Vector2.Reflect(direction, hit.normal);

            hit = Physics2D.CircleCast(origin, radius, direction);

            Debug.DrawLine(origin, direction * 10000, UnityEngine.Color.blue);
            DrawCircle(origin, 1.0f, UnityEngine.Color.blue);
        }
    }


    private void DrawCircle(Vector2 center, float radius, UnityEngine.Color color)
    {
        Vector2 prevPoint = new Vector2(Mathf.Sin(0f), Mathf.Cos(0f));

        for (float t = 0.1f; t < 2 * Mathf.PI; t = t + 0.1f)
        {
            var nextPoint = new Vector2(Mathf.Sin(t), Mathf.Cos(t));

            Debug.DrawLine(center + prevPoint, center + nextPoint, color);

            prevPoint = nextPoint;
        }


    }
}