Quaternion.Euler rotates wrong axis

Question

I have this problem where i have this: enter image description here

And then, i tried to rotate the y axis and that the "PartToRotate" follows the "enemy". enter image description here

But then, it rotates the axis z for -90 and i dont know why. enter image description here

Therefore i appreciate if you can help me with this. I leave all the code here:

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

public class Turret : MonoBehaviour
{

    private Transform target;
    public float range = 15f;
    public Transform partToRotate;

    public string enemyTag = "Enemy";

    // Start is called before the first frame update
    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 = Vector2.Distance(transform.position, enemy.transform.position);
            if(distanceToEnemy < shortestDistance)
            {
                shortestDistance = distanceToEnemy;
                nearestEnemy = enemy;
            }
        }
        
        if(nearestEnemy != null && shortestDistance <= range)
        {
            target = nearestEnemy.transform;
        }
        else
        {
            target = null;
        }
        
    }

    // Update is called once per frame
    void Update()
    {
        if (target == null)
        {
            return;
        }

        Vector3 dir = target.position - transform.position;
        Quaternion lookRotation = Quaternion.LookRotation(dir);
        Vector3 rotation = lookRotation.eulerAngles;
        partToRotate.rotation = Quaternion.Euler(0f, rotation.y, 0f);

    }

    void OnDrawGizmosSelected ()
    {
        Gizmos.color = Color.red;
        Gizmos.DrawWireSphere(transform.position, range);
    }

}

Here are the photos. enter image description here . thats how looks before, and the idea with the new code Vector3 direction = target.position - transform.position; float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg; partToRotate.rotation = Quaternion.Euler(0, 0, angle); Vector3 direction = target.position - transform.position; float angle = Mathf.Atan2(direction.y, direction.x) * Mathf.Rad2Deg; partToRotate.rotation = Quaternion.Euler(0, 0, angle); is that the "partToRotate" follows the enemy (target), and he do that, but it still get (plus the z, that is the axis i want) the x axis. enter image description here

Answer 1

Without seeing the values for target.position and transform.position can't ensure it but you may be experiencing a gimbal lock .

To avoid gimbal locking you must avoid euler angles and use only quaternions. In your code you create a quaternion, then you get the euler angles and then you create a new quaternion using only the Y axis of those euler angles. I assume that's to restrict the rotation to be on the XZ plane, you can do the same without using euler angles like this:

Vector3 dir = target.position - transform.position;
Quaternion lookRotation = Quaternion.LookRotation(new Vector3(dir.x, 0, dir.z));
partToRotate.rotation = lookRotation;