射线相关

预备知识：

Raycast：在场景中投下可与所有碰撞器碰撞的一条光线
注意：如果射线从碰撞体的内部或者背面打，Raycast不检测碰撞

激光制作：创建新材质，其shader改为Particles/Addtive并添加激光图片，再拖到LineRenderer组件的材质

LayerMask 只投射指定层的物体

Raycast在场景中投下可与所有碰撞器碰撞的一条光线。

RaycastAll在场景投射一条射线并返回所有碰撞。注意不保证顺序。

主要是两种语法：
1.Raycast(Ray ray)
2.Raycast(Vector3 origin,Vector3 direction)

点哪移动到哪

using UnityEngine;
using System.Collections;
/// <summary> 射线从摄像机发出，另一点为鼠标在世界坐标系的位置/// </summary>
public class RayTest : MonoBehaviour {

    private Ray ray ;
    private RaycastHit hit;//射线碰到的碰撞信息

    private NavMeshAgent agent;
    public Camera mapCamera;//小地图摄像机
    private void Start()
    {
        agent = this.GetComponent<NavMeshAgent>();
    }
    private void Update()
    {
        //起始位置(摄像机)
        //方向（跟随鼠标）
        ray = mapCamera.ScreenPointToRay(Input.mousePosition);
        if (Physics.Raycast(ray, out hit, 100)
                                    &&Input.GetMouseButtonDown(0))
        {
            if(hit.collider.tag == "Plane")
            {
                agent.SetDestination(hit.point);
                Debug.DrawLine(ray.origin, hit.point, Color.red);
            }
        }
    }

}

 射线拾取物体

using UnityEngine;
using System.Collections;
/// <summary>
/// 射线拾取物体
/// </summary>
public class RayCarry : MonoBehaviour
{
    private Ray ray;
    private RaycastHit hit;
    public LayerMask layer;
    public Transform carryParent;//摄像机前方空物体
    private Transform carryObj;//射线拾取到的物体
    private bool flag = false;
    private void Update()
    {
        ray = Camera.main.ScreenPointToRay(Input.mousePosition);
        if (Input.GetMouseButtonDown(0))
        {
            flag = !flag;
        }

        if (Physics.Raycast(ray, out hit, 30, layer.value) && flag == true)
        {

            carryObj = hit.transform;//记录拾取到的物体
            carryObj.parent = carryParent;//认父物体
            carryObj.localPosition = Vector3.zero;
            carryObj.localEulerAngles = Vector3.zero;
        }

        if (flag == false)
        {
            carryObj.parent = null;//取消父子关系
            //锁定x z 轴角度
            carryObj.eulerAngles = new Vector3(0, carryObj.eulerAngles.y, 0);
        }

    }
}

 从枪口位置形成射线，准心效果

using UnityEngine;
using System.Collections;
/// <summary>
/// 从枪口位置形成射线，准心效果
/// </summary>
public class TransRay : MonoBehaviour {
    private RaycastHit hit;//射线碰到的碰撞信息
    public LayerMask layer;
    public Transform gunPos;//枪口位置
    public RectTransform UIPos;//准心
    private void Update () {
        if (Physics.Raycast(gunPos.position, gunPos.forward, out hit,
                                                                                        10, layer.value))
        {
            Vector3 UIPoint = Camera.main.WorldToScreenPoint(hit.point);
            UIPos.gameObject.SetActive(true);
            UIPos.position = UIPoint;
            Debug.DrawLine(gunPos.position, hit.point, Color.red);
        }
        else
            UIPos.gameObject.SetActive(false);
    }
}

从枪口位置形成射线，准心,激光效果

using UnityEngine;
using System.Collections;
/// <summary>
/// 从枪口位置形成射线，准心,激光效果
/// </summary>
public class TransRay : MonoBehaviour {
    private RaycastHit hit;//射线碰到的碰撞信息
    public LayerMask layer;
    public Transform gunPos;//枪口位置
    public RectTransform UIPos;//准心
    private LineRenderer line;
    private void Start()
    {
        line = this.GetComponent<LineRenderer>();
    }
    private void Update () {
        if (Physics.Raycast(gunPos.position, gunPos.forward, out hit,
                                                                                        10, layer.value))
        {
            Vector3 UIPoint = Camera.main.WorldToScreenPoint(hit.point);
            UIPos.gameObject.SetActive(true);
            UIPos.position = UIPoint;
            //线渲染控制
            line.enabled = true;//单独组件勾选
            //设置位置
            line.SetPosition(0, gunPos.position);
            line.SetPosition(1, hit.point);

            Debug.DrawLine(gunPos.position, hit.point, Color.red);
        }
        else
        {
            UIPos.gameObject.SetActive(false);
            line.enabled = false;
        }
            
    }
}

 球形射线

using UnityEngine;
using System.Collections;

public class RayOther : MonoBehaviour {
    private RaycastHit[] hits;
    public LayerMask layer;
    private Collider[] colliders;
    private void Update () {
        //球形射线
        colliders = Physics.OverlapSphere(transform.position, 5, layer.value);

        if(Input.GetMouseButtonDown(0))
        {
            foreach (var collider in colliders)
            {
                Debug.DrawLine(transform.position, collider.transform.position, Color.red);
                collider.GetComponent<Renderer>().material.color = Color.green;
                collider.GetComponent<Score>().blood -= 50;
            }
        }
    }
}