原来一直用Physics.Raycast或者对应的2D射线检测，今天无意中发一个有趣射线检测，话不多说直接上示例

void Update()

LateUpdate()

示例代码

using UnityEngine;
public class PlaneRayExample : MonoBehaviour
{
    //需要移动的cube的预制
    public GameObject m_Cube;
    //距离射线原点的距离
    public float m_DistanceZ = 10.0f;

    Plane m_Plane;
    Vector3 m_DistanceFromCamera;

    void Start()
    {
        //这是离Plane放置的距离有多远
        m_DistanceFromCamera = new Vector3(Camera.main.transform.position.x, Camera.main.transform.position.y, Camera.main.transform.position.z + m_DistanceZ);
        //在距离m_DistanceFromCamera处，创建一个方向为forward的Plane
        m_Plane = new Plane(Vector3.forward, m_DistanceFromCamera);
    }

    void Update()
    {

        if (Input.GetMouseButton(0))
        {

            Ray ray = Camera.main.ScreenPointToRay(Input.mousePosition);

            float enter = 0.0f;

            if (m_Plane.Raycast(ray, out enter))
            {
                Debug.DrawRay(ray.origin, ray.direction * enter, Color.green);
                //得到点击的点
                Vector3 hitPoint = ray.GetPoint(enter);
                //将你的方块游戏对象移动到你点击的地方
                m_Cube.transform.position = hitPoint;
            }
            else
            {
                Debug.Log($"enter{enter}");
                Debug.DrawRay(ray.origin, ray.direction * 10, Color.red);
            }
        }
    }

    Plane plane = new Plane(Vector3.up, Vector3.zero);

    private void LateUpdate()
    {
        if (Input.GetMouseButton(0))
        {
            var ray = Camera.main.ScreenPointToRay(Input.mousePosition);

            float ent = 100.0f;
            if (plane.Raycast(ray, out ent))
            {
                Debug.Log("Plane Raycast hit at distance: " + ent);
                var hitPoint = ray.GetPoint(ent);

                var go = GameObject.CreatePrimitive(PrimitiveType.Cube);
                go.transform.position = hitPoint;
                Debug.DrawRay(ray.origin, ray.direction * ent, Color.green);
            }
            else
            {
                Debug.DrawRay(ray.origin, ray.direction * 10, Color.red);
            }

        }
    }

}