c# - Physics2D.OverlapCircleAll 未检测到其他游戏对象

Question

我有一个敌人的预制件，它会在玩家周围的随机位置多次生成。然而，有时这会使一个敌人预制件与另一个敌人预制件重叠。

因此，我编写了一个脚本，该脚本使用 Physics2D.OverlapCircleAll() 在实例化敌人预制件之前检测所有碰撞器，从而避免敌人预制件与现有敌人重叠。我的问题是 OverlapCircleAll() 没有检测到预制件的其他实例。

我也已经尝试过使用 Physics2D.OverlapBoxAll。如果我生成超过 30 个这样的“敌人预制件”，至少有一个会与另一个敌人重叠

这是用于检测重叠的代码:

public void SpawnEachEnemy(GameObject Enemy)
{
    Vector3 futurePosition = new Vector2(UnityEngine.Random.Range(UpperLeft.transform.position.x, DownRight.transform.position.x),
                                UnityEngine.Random.Range(UpperLeft.transform.position.y, DownRight.transform.position.y));
    bool correctPosition = false;
    while (!correctPosition)
    {
        Collider2D[] collider2Ds = Physics2D.OverlapCircleAll(futurePosition,0.2f);
        if (collider2Ds.Length > 0)
        {
            //re-spawning to prevent overlap
            futurePosition = new Vector2(UnityEngine.Random.Range(UpperLeft.transform.position.x, DownRight.transform.position.x),
                                UnityEngine.Random.Range(UpperLeft.transform.position.y, DownRight.transform.position.y));
        }
        else
        {
            correctPosition = true;
        }
    }

    GameObject b = Instantiate(Enemy) as GameObject;
    b.transform.position = futurePosition;
    b.transform.parent = this.transform;
}

Answer 1

Louis Garczynski 提到了一些可能性，但没有提到的是，如果这些都在单个帧的跨度内实例化(基于评论说 SpawnEachEnemy 的猜测被称为在循环中)，那么您可能需要在 Physics2D 设置 下启用Auto Sync Transforms:

这minimal reproducible example当在新的 3D 项目场景中连接到相机时，在启用 Auto Sync Transforms 的情况下应该可以按照您的预期工作，并且在禁用时将无法防止重叠。这可能是阻止它为您工作的原因:

using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class TestScript : MonoBehaviour
{
    Vector3 upperLeft;
    Vector3 downRight;

    GameObject prefab;

    // Start is called before the first frame update
    void Start()
    {
        transform.position = new Vector3(0, 0, -3);
        upperLeft = new Vector3(-1, -1);
        downRight = new Vector3(1, 1);

        prefab = GameObject.CreatePrimitive(PrimitiveType.Sphere);
        DestroyImmediate(prefab.GetComponent<SphereCollider>());
        prefab.transform.localScale = 0.4f * Vector3.one;
        prefab.AddComponent<CircleCollider2D>();

        for (int i = 0; i < 12; i++)
        {
            SpawnEachEnemy(prefab);
        }

        prefab.SetActive(false);

    }


    public void SpawnEachEnemy(GameObject Enemy)
    {
        Vector3 futurePosition;
        Collider2D[] collider2Ds;

        do { 
            futurePosition = new Vector2(
                UnityEngine.Random.Range(
                    upperLeft.x,
                    downRight.x),

                UnityEngine.Random.Range(
                    upperLeft.y, 
                    downRight.y));

            collider2Ds = Physics2D.OverlapCircleAll(futurePosition, 0.2f)
        } 
        while (collider2Ds.Length > 0)

        GameObject b = Instantiate(Enemy) as GameObject;
        b.transform.position = futurePosition;
        b.transform.parent = this.transform;
    }
}