Unity敌人脚本异常：无法追踪玩家但仍可造成伤害问题求助

问题现象 #

敌人脚本最初运行正常，现在靠近敌人时它不会追踪玩家，但接触敌人时仍能正常造成伤害。

敌人脚本代码 #

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

public class Enemy : Mover
{
    // Experience
    public int xpValue = 1;

    // Logic
    public float triggerLength = 1;
    public float chaseLength = 5;
    private bool chasing;
    private bool collidingWithPlayer;
    private Transform playerTransform;
    private Vector3 startingPosition;

    // Hitbox
    public ContactFilter2D filter;
    private BoxCollider2D hitbox;
    private Collider2D[] hits = new Collider2D[10];

    protected override void Start()
    {
        base.Start();
        playerTransform = GameManager.instance.player.transform;
        startingPosition = transform.position;
        hitbox = transform.GetChild(0).GetComponent<BoxCollider2D>();
    }

    private void FixedUpdate()
    {
        // Is the player in range?
        if (Vector3.Distance(playerTransform.position, startingPosition) < chaseLength)
        {
            if (Vector3.Distance(playerTransform.position, startingPosition) < triggerLength)
                chasing = true;
            
            if (chasing)
            {
                if (!collidingWithPlayer)
                {
                    UpdateMotor((playerTransform.position - transform.position).normalized);
                }
            }
            else
            {
                UpdateMotor(startingPosition - transform.position);
            }
        }
        else
        {
            UpdateMotor(startingPosition - transform.position);
            chasing = false;
        }

        // Check for overlaps
        collidingWithPlayer = false;
        boxCollider.OverlapCollider(filter, hits);
        for (int i = 0; i < hits.Length; i++)
        {
            if (hits[i] == null)
                continue;

            if (hits[i].tag == "Fighter" && hits[i].name == "Player")
            {
                collidingWithPlayer = true;
            }

            // The array is not cleaned up, so we do it ourself
            hits[i] = null;
        }
    }

    protected override void Death()
    {
        Destroy(gameObject);
        GameManager.instance.GrantXp(xpValue);
        GameManager.instance.ShowText("+" + xpValue + " xp", 30, Color.magenta, transform.position, Vector3.up * 40, 1.0f);
    }
}

错误日志说明 #

以下错误属于Unity编辑器的可视化图（如状态机、Shader Graph等）异常，与运行时的敌人追踪逻辑无关，不会影响游戏运行：

错误: NullReferenceException: 对象引用未设置到对象的实例
UnityEditor.Graphs.Edge.WakeUp () (at <06397f6908034403aa752a7eb86035b0>:0)
UnityEditor.Graphs.Graph.DoWakeUpEdges (System.Collections.Generic.List1[T] inEdges, System.Collections.Generic.List1[T] ok, System.Collections.Generic.List`1[T] error, System.Boolean inEdgesUsedToBeValid) (at <06397f6908034403aa752a7eb86035b0>:0)
UnityEditor.Graphs.Graph.WakeUpEdges (System.Boolean clearSlotEdges) (at <06397f6908034403aa752a7eb86035b0>:0)
UnityEditor.Graphs.Graph.WakeUp (System.Boolean force) (at <06397f6908034403aa752a7eb86035b0>:0)
UnityEditor.Graphs.Graph.WakeUp () (at <06397f6908034403aa752a7eb86035b0>:0)
UnityEditor.Graphs.Graph.OnEnable () (at <06397f6908034403aa752a7eb86035b0>:0)

追踪失效的原因与修复 #

核心问题 #

脚本中判断玩家是否在追踪范围内时，使用的是敌人初始位置与玩家位置的距离，而非敌人当前位置与玩家的距离。一旦敌人离开初始位置，即使玩家就在敌人身边，只要离初始位置超出chaseLength范围，敌人就不会触发追踪。

修复后的FixedUpdate代码 #

private void FixedUpdate()
{
    // 计算玩家与敌人当前位置的距离
    float distanceToPlayer = Vector3.Distance(playerTransform.position, transform.position);
    // Is the player in range?
    if (distanceToPlayer < chaseLength)
    {
        if (distanceToPlayer < triggerLength)
            chasing = true;
        
        if (chasing)
        {
            if (!collidingWithPlayer)
            {
                UpdateMotor((playerTransform.position - transform.position).normalized);
            }
        }
        else
        {
            UpdateMotor(startingPosition - transform.position);
        }
    }
    else
    {
        UpdateMotor(startingPosition - transform.position);
        chasing = false;
    }

    // Check for overlaps
    collidingWithPlayer = false;
    boxCollider.OverlapCollider(filter, hits);
    for (int i = 0; i < hits.Length; i++)
    {
        if (hits[i] == null)
            continue;

        if (hits[i].tag == "Fighter" && hits[i].name == "Player")
        {
            collidingWithPlayer = true;
        }

        // The array is not cleaned up, so we do it ourself
        hits[i] = null;
    }
}

额外检查项 #

• 确认GameManager.instance.player不为空，确保玩家对象在场景中且正确赋值
• 检查triggerLength和chaseLength的数值设置，确保triggerLength < chaseLength

内容的提问来源于stack exchange，提问作者Niks Rodžers