思考如何試圖抓住目標對象的程式設計

參考文章：Enemy Follow Script (AI) in Unity

下載範例：http://github.com/tejas123/enemy-follow-script-ai/archive/master.zip

這個腳本(Enemy.cs)在需要敵方物體跟隨玩家或者其他想要瞄準的物體時很有用。 當敵人朝著目標物體(上圖中白色物體)移動時，敵人(Enemy)產生跳躍效應。 看起來好像敵人自己在思考，像是有點具備人工智慧(AI)的感覺，敵人可以思考行動路徑試圖抓住目標對象。

程式解析如下：

1.前面沒有障礙物

if (!isThereAnyThing) {

Vector3 relativePos = target.transform.position - transform.position;

Quaternion rotation = Quaternion.LookRotation (relativePos);

transform.rotation = Quaternion.Slerp (transform.rotation, rotation, Time.deltaTime);

}

2.往前移動

transform.Translate (Vector3.forward * Time.deltaTime * speed);

3.檢查前方有沒有障礙物，並使用Physics.Raycast()進行偵測

Transform leftRay = transform;

Transform rightRay = transform;

                

if (Physics.Raycast (leftRay.position + (transform.right * 7), transform.forward, range)) {

isThereAnyThing = true;

transform.Rotate (Vector3.up * Time.deltaTime * rotationSpeed);

}

                

if (Physics.Raycast (rightRay.position - (transform.right * 7), transform.forward, range)) {

isThereAnyThing = true;

transform.Rotate (Vector3.up * Time.deltaTime * rotationSpeed);

}

4.已經通過障礙物

if (Physics.Raycast (transform.position - (transform.forward * 4), transform.right, 10)) {

// Just making this boolean variable false it means there is nothing in front of object.

isThereAnyThing = false;

}

if (Physics.Raycast (transform.position - (transform.forward * 4), -transform.right, 10)) {

// Just making this boolean variable false it means there is nothing in front of object.

isThereAnyThing = false;

}

5.輸出除錯資訊

Debug.DrawRay (transform.position + (transform.right * 7), transform.forward * 20, Color.red);

Debug.DrawRay (transform.position - (transform.right * 7), transform.forward * 20, Color.red);

Debug.DrawRay (transform.position - (transform.forward * 4), - transform.right * 20, Color.yellow);

Debug.DrawRay (transform.position - (transform.forward * 4), transform.right * 20, Color.yellow);