Order of the rotations around the axes with Euler angles

Questions & Answers
1

According to the documentation, with Euler angles:

rotations are performed around the Z axis, the X axis, and the Y axis, in that order.

When I try to reproduce it in the inspector and with scripts, it seems that the rotation order is “YXZ”, and not “ZXY”.

Do you know the reason of this behaviour ? If Unity use the “YXZ” order, do you know how to convert the euler angles to “ZXY” ?

You can check the GIF files or the script below:

using UnityEngine;
public class RotationTest : MonoBehaviour
{
    public Vector3 rotation;
    public bool useYXZ = true;
    
    private void Awake()
    {
        if (useYXZ) ApplyQuaternionYXZ();
        else ApplyQuaternionZXY();

        Debug.Log(transform.eulerAngles);
    }

    private void ApplyQuaternionYXZ()
    {
        transform.RotateAround(transform.position, transform.up, rotation.y);
        transform.RotateAround(transform.position, transform.right, rotation.x);
        transform.RotateAround(transform.position, transform.forward, rotation.z);
    }

    private void ApplyQuaternionZXY()
    {
        transform.RotateAround(transform.position, transform.forward, rotation.z);
        transform.RotateAround(transform.position, transform.right, rotation.x);
        transform.RotateAround(transform.position, transform.up, rotation.y);
    }
}

155543-yxz.gif
155544-zxy.gif

2

Rotations are performed around the global axis, not local. You can test with the following code:

transform.RotateAround(transform.position, Vector3.forward, rotation.z);
transform.RotateAround(transform.position, Vector3.right, rotation.x);
transform.RotateAround(transform.position, Vector3.up, rotation.y);