Question

我正在团结一致进行塔防游戏，但我被卡住了。我希望我的枪或炮塔能够面对敌人，直到他们超出射程，但每0.5秒后，它会更新并面对其范围内的另一个敌人，尽管第一个敌人也在范围内。

这是我的代码：

void Start () 
{
    InvokeRepeating("UpdateTarget", 0f , 0.5f );
}   

void UpdateTarget()
{
    GameObject[] enemies = GameObject.FindGameObjectsWithTag(enemyTag);
    float shortestDistance = Mathf.Infinity;
    GameObject nearestEnemy = null;

    foreach (GameObject enemy in enemies)
    {
        float distanceToEnemy = Vector3.Distance(transform.position, enemy.transform.position);
        if (distanceToEnemy < shortestDistance)
        {
            shortestDistance = distanceToEnemy;
            nearestEnemy = enemy;
        }
    }

    if (nearestEnemy != null && shortestDistance <= range)
    {
        target = nearestEnemy.transform;          
    }
    else 
    { 
        target = null; 
    }        
}

Answer 1

你必须在UpdateTarget中包含一个测试，该测试应首先检查，如果nearestEnemy仍在该范围内，并且在这种情况下退出该函数，否则搜索新目标。

逻辑看起来应该是这样的：

//keep old target?
if(nearestEnemy != null)
{
  //calculate distance of current target here..
  if(distance <= range)
     return; //keep this enemy as target
}
//here comes your code for finding a new target...

Answer 2

GameObject.FindGameObjectsWithTag对性能的影响更大，我建议你创建一个圆形对撞机2d并将其设置为触发，当调用OnTriggerEnter2D时，你可以获取敌人并举起一个旗帜，这样其他敌人就不会被触发之后，当对该敌人召唤OnTriggerExit2D时，你可以开始寻找另一个敌人，或者选择仍在该对手半径范围内的敌人。

private bool _foundEnemy;
private Enemy _currentEnemy;

private void OnTriggerEnter2D(Collider2D collision)
{
    if (_foundEnemy) return;

    _currentEnemy = collision.GetComponent<Enemy>();
    // your code here
    _foundEnemy = true;
}

private void OnTriggerExit2D(Collider2D collision)
{
    if(_currentEnemy!=null && collision.GetComponent<Enemy>() == _currentEnemy)
        _foundEnemy = false;
}

Answer 3

你并不完全清楚你想要实现什么样的行为，但它似乎是锁定目标直到它死了，然后才切换到另一个目标。这是您代码中的一个简单修复;但是我发现了其他一些问题：

冗余代码，如块和变量。
几乎是失败如何关注Single Responsibility Principle的示例。
您不需要“one or other”方法，因为其他答案正在显示。您可以使用简单boolean flag作为切换来获取 两种行为 。

这里有一些注释代码可以解释所有这些事情，希望您可以从参考资料中学习：

//Defines how to get and compare distance; used during sorting
public class DistanceComparer<T> : IComparer<T> where T : GameObject {
   public int Compare(T a, T b) {
       return Vector3.Distance(a.transform.position, b.transform.position);
   }
}

public var bool lockToTargetUntilDead = true; //Should lock to target till it's dead (true)? Or switch to nearest if the nearest changes (false)?

//Finds nearest enemy
GameObject FindNearestEnemy() {
    var enemies = GameObject.FindGameObjectsWithTag(enemyTag);
    if (enemies==null || enemies.Length==0) return null; //No enemies anywhere
    Array.Sort(enemies, new DistanceComparer()); //Sort enemies by distance
    return enemies[0]; //Return closest enemy
}

//Determines if enemy is within range (Note: If enemy is null, it's not in range =P)
bool IsWithinRange(GameObject enemy) {
    return enemy != null && Vector3.Distance(transform.position, enemy.transform.position) <= range;
}

//Updates target
void UpdateTarget() {
    var nearestEnemy = FindNearestEnemy();
    if(!IsWithinRange(nearestEnemy)) { //No enemies within range...
        if(target != null) target = null; //Forget current target.
        return; //Return-early.
    }
    if(lockToTargetUntilDead && target!=null) return; //If locking to current target and it ain't dead yet, return-early
    target = nearestEnemy; //If not locking to target, or doesn't have a target, new target!
}

void Start () {
    InvokeRepeating("UpdateTarget", 0f , 0.5f );
}

在c＃游戏代码中需要帮助

3 个答案: