如何让 Physics2D.OverlapBoxAll() 激活 x 时间，并且只与它碰撞的新对象交互？

Question

我有一个非常简单的 2D 游戏，其中玩家位于左侧，而敌人位于右侧并向玩家移动。

玩家会用剑攻击敌人，我现在有这个功能：

[SerializeField] int damage = 1;
[SerializeField] Transform attackPos;
[SerializeField] LayerMask whatIsEnemy;
[SerializeField] float attackRangeX;
[SerializeField] float attackRangeY;

private void Update()
{
    if (Input.GetKeyDown(KeyCode.A))
    {
        DamageEnemies();
    }
}

private void DamageEnemies()
{
    Collider2D[] enemiesToDamage = Physics2D.OverlapBoxAll(attackPos.position, new Vector2(attackRangeX, attackRangeY), 0, whatIsEnemy);
    for (int i = 0; i < enemiesToDamage.Length; i++)
    {
        enemiesToDamage[i].GetComponent<EnemyController>().TakeDamage(damage);
    }
}

attackPos 游戏对象只是放置在玩家面前。 AttackRangeX 和 Y 类似于玩家面前的一个正方形。

这个设置的问题是当按下攻击键时，它只会在那个时间点与里面的敌人互动，也就是单帧。

我怎样才能让碰撞激活 5 秒，但只对 new 个敌人造成伤害一次。我不希望它继续伤害它已经伤害过的敌人。

Answer 1

您可以将已经损坏的敌人存储在一个列表中，如果您已经损坏了它们，则跳过它们。

有些人更喜欢使用协程 (IEnumerator) 以获得更长的主动伤害，但为了暂时保持简单，我会使用一个简单的计时器。

[SerializeField] int damage = 1;
[SerializeField] Transform attackPos;
[SerializeField] LayerMask whatIsEnemy;
[SerializeField] float attackRangeX;
[SerializeField] float attackRangeY;

// Adjust here how long the damage should take on (in seconds)
[SerializeField] float damageDuration = 5;

// This is the countdown timer for the damage
private float damageTimer;

// Flag that controls the damage mode
private bool isDamaging;

// Here you will store the already damaged enemies to skip them later
private List<Collider2D> alreadyDamagedEnemies = new List<Collider2D>();

private void Start()
{
    // Initialize the timer
    damageTimer = damageDuration;
}

private void Update()
{
    // only take keyboard input if not already damaging
    // to prevent a peanant press
    if(!isDamaging)
    {
        // Hint: If you want you could with a second timer at this point add
        // a cooldown so you can not directly atack again right after the damage duration
        // Just thought it might be interesting for you so I leave it as a homework ;) 

        if (Input.GetKeyDown(KeyCode.A))
        {
            // Only activate the damaging
            isDamaging = true;
        }
    }
    else // We are currently in damage mode
    {
        // If end of timer reset and leave damage mode
        if(damageTimer <= 0)
        {
            // Reset the timet
            damageTimer = damageDuration;

            // Switch off damage mode
            isDamaging = false;

            // Reset the list
            alreadyDamagedEnemies.Clear();
        }
        // else make damage and redue the timer
        else
        {
            DamageEnemies();

            // Reduce the timer by the time passed since last frame
            damageTimer-= Time.deltaTime;
        }
    }
}

private void DamageEnemies()
{
    Collider2D[] enemiesToDamage = Physics2D.OverlapBoxAll(attackPos.position, new Vector2(attackRangeX, attackRangeY), 0, whatIsEnemy);

    foreach (var currentEnemy in enemiesToDamage)
    {

        // Skip if you already damaged this enemy
        if(alreadyDamagedEnemies.Contains(currentEnemy) continue;

        currentEnemy.GetComponent<EnemyController>().TakeDamage(damage);

        // Add the damaged enemy to the list
        alreadyDamagedEnemies.Add(currentEnemy);
    }
}

这个例子假设你按了一次A但是如果同时松开键也会造成整整5秒的伤害。

如果您希望它只在按键按下期间发生并且最多 5 秒，我相信您将能够使用
自行解决 if(Input.GetKey(KeyCode.A)){ ... }.

如何让 Physics2D.OverlapBoxAll() 激活 x 时间，并且只与它碰撞的新对象交互？

How to make Physics2D.OverlapBoxAll() Active for x time, and only interact with the new objects it collides with?

unity3d

unity3d-2dtools