敌人gameObject没有移动

我遇到了一个关于敌人执行的问题。首先，我遵循本教程。我有一个带有盒子碰撞器的敌人的游戏对象，基本上就是我所需要的。

using UnityEngine;
using System.Collections;
public class Enemy : MonoBehaviour {
[SerializeField]
private float rotationSpeed = 180; // In degrees per second
[SerializeField]
private float movementSpeed = 1f; // In units per second
[SerializeField]
private float meshRadius = 1f; // In units
private IEnumerator turnTowardsPlayerCoroutine;
private IEnumerator moveTowardsPlayerCoroutine;
void OnTriggerEnter(Collider collider)
{
    if (collider.gameObject.tag == "Player")
    {
        float playerDistance = Vector3.Distance(collider.transform.position, transform.position);
        // Ignore trigger events from the inner colliders
        if (playerDistance >= 2f * meshRadius)
        {
            turnTowardsPlayerCoroutine = TurnTowardsPlayer(collider.transform);
            moveTowardsPlayerCoroutine = MoveTowardsPlayer(collider.transform);
            StartCoroutine(turnTowardsPlayerCoroutine);
            StartCoroutine(moveTowardsPlayerCoroutine);
        }
    }
}
void OnTriggerExit(Collider collider)
{
    if (collider.tag == "Player")
    {
        float playerDistance = Vector3.Distance(collider.transform.position, transform.position);
        // Ignore trigger events from the inner colliders
        if (playerDistance >= 2f * meshRadius)
        {
            StopCoroutine(turnTowardsPlayerCoroutine);
            StopCoroutine(moveTowardsPlayerCoroutine);
        }
    }
}
private IEnumerator TurnTowardsPlayer(Transform player)
{
    while (true)
    {
        Quaternion targetRotation = Quaternion.LookRotation(player.position - transform.position, Vector3.up);
        targetRotation.x = 0f;
        targetRotation.z = 0f;
        transform.rotation = Quaternion.RotateTowards(transform.rotation, targetRotation, rotationSpeed * Time.deltaTime);
        yield return 0;
    }
}
private IEnumerator MoveTowardsPlayer(Transform player)
{
    while (true)
    {
        Vector3 playerDirection = transform.position - player.position;
        playerDirection.y = 0;
        playerDirection = playerDirection.normalized;
        Vector3 deltaMovement = playerDirection * movementSpeed * Time.deltaTime;
        int layermask = LayerMask.GetMask("Environment");
        Vector3 movingTowards = transform.position - playerDirection*meshRadius + (new Vector3(0f, 0.1f, 0f));
        if (Physics.Raycast(movingTowards, Vector3.down, 0.25f, layermask))
        {
            transform.position -= deltaMovement;
        }
        yield return 0;
    }
}
}

结果是，当我进入敌人必须攻击我的区域时，敌人向我旋转，但他没有移动。是我忘了什么还是出了什么问题?