unity, 鼠标与场景交点

在鼠标与场景交点上放一个mark，并于1s后消失：

新建一个空GameObject，命名为moushHitTest，添加下面脚本：

using UnityEngine;
using System.Collections;

public class mouseHit : MonoBehaviour {
    public GameObject m_moushHitMarkPrefab;
    // Use this for initialization
    void Start () {
    
    }
    
    // Update is called once per frame
    void Update () {

if (Input.GetMouseButtonDown (0)) {//left button down
            Ray camRay = Camera.main.ScreenPointToRay (Input.mousePosition);
            RaycastHit hitInfo;
            float camRayLength = 100f;
            bool isHit = Physics.Raycast (camRay,out hitInfo,camRayLength);
            if (isHit) {
                Debug.Log(hitInfo.point);
                Object instance=Instantiate (m_moushHitMarkPrefab, hitInfo.point, Quaternion.identity);
                instance.name="hitMark";
                //about startCoroutine and yield: http://stackoverflow.com/questions/12932306/how-does-startcoroutine-yield-return-pattern-really-work-in-unity
                StartCoroutine(delayDestroy(instance));

}
        }

}

IEnumerator delayDestroy(Object instance){
        yield return new WaitForSeconds (1.0f);
        Destroy (instance);
    }

}