画一个圆圈在被锁物体上：新建一个UI
修改cameraconctoller，

using UnityEngine.UI;//取得ui类别


 public bool lockState;//查看是否锁死

 lockState = false;//在引擎里面显示是否被锁死

        
        if (cols.Length == 0)//长度为0那么就是没锁过东西
        {
            lockTarget = null;
            lockDot.enabled = false;//圆圈不显示
            lockState = false;


        }
        else//否则锁过
        {
            foreach (var col in cols)
            {
                // print(col.name);
                if (lockTarget == col.gameObject)
                {
                    lockTarget = null;
                    lockDot.enabled = false;
                    lockState = false;
                    break;
                }
                lockTarget = col.gameObject;//将被锁定的东西赋值给locktarget
                lockDot.enabled = true;//显示圆圈
                lockState = true;
                break;
            }

        }

        
        //else
        //{
        //    //relese lock
        //    lockTarget = null;//如果里面有被锁物件那么就清空他
        //}
    }
}