如何计算蛇游戏中玩家身后游戏对象的角度

问题描述

我正在使用 2d Orthographic 相机在 Unity 引擎中创建 Snake 游戏。我想在某个点检测食物颗粒是在蛇的后面还是前面。

我尝试了多种方法，例如这种方法，但我一直无法解决这个问题。

IEnumerator ChangeFood()
    {
        //waits three seconds then puts all active food instances into a list,then picks a random object from that list and changes it
        yield return new WaitForSeconds(3f);
        GameObject[] foodList = GameObject.FindGameObjectsWithTag("Food");

        if (foodList.Length > 0)
        {
            //List<Vector2> foodsBehindSnake = new List<Vector2>();
            foreach(GameObject food in foodList)
            {
                //If angle required to turn towards food is greater than 90,food will be considered as behind snake
                float angletoFood = Mathf.atan2(food.transform.position.y - this.transform.position.y,food.transform.position.x - this.transform.position.x) * Mathf.Rad2Deg;
                Debug.Log(angletoFood);
                if (angletoFood <=90f)
                {
                    Debug.Log("FOOD AT" + food.transform.position + " IS BEHIND SNAKE");
                    food.GetComponent<SpriteRenderer>().color = Color.magenta;
                }
                
            }
        }

        yield return null;
    } 

here is a rough sketch of what I am trying to achieve

解决方法

为此使用 Vector3.Dot()。请记住，它作用于方向，而不是位置 - 所以您可能想将蛇头的 transform.forward 与食物和头部位置的差异进行比较（例如，从头部到食物的方向）。