Unity3D中通过四元数得到欧拉角

	void Start () {
        gameObject.transform.rotation = QuaternionToEular(-89.0f,50.0f,100.0f);
        
    }
	
	// Update is called once per frame
	void Update () {
	
	}
    private Quaternion QuaternionToEular(float XX, float YY,float ZZ)
    {
        float X = XX /180* Mathf.PI;
        float Y = YY / 180 * Mathf.PI;
        float Z = ZZ / 180 * Mathf.PI;
        float x = Mathf.Cos(Y / 2) * Mathf.Sin(X / 2) * Mathf.Cos(Z/ 2) +Mathf.Sin(Y / 2) * Mathf.Cos(X / 2) * Mathf.Sin(Z/ 2);       
        float y = Mathf.Sin(Y / 2)*Mathf.Cos(X/ 2)*Mathf.Cos(Z / 2) -Mathf.Cos(Y / 2)*Mathf.Sin(X/ 2)*Mathf.Sin(Z/ 2);
        float z=  Mathf.Cos(Y / 2) * Mathf.Cos(X/ 2) * Mathf.Sin(Z/ 2)-Mathf.Sin(Y / 2) * Mathf.Sin(X/ 2) * Mathf.Cos(Z / 2);
        float w=Mathf.Cos(Y / 2)* Mathf.Cos(X / 2)* Mathf.Cos(Z/ 2) + Mathf.Sin(Y / 2)*Mathf.Sin(X / 2)*Mathf.Sin(Z / 2);
        Quaternion quataion = new Quaternion(x, y, z, w);
        return quataion;
    }
}

通过四元数得到欧拉角，最后结果

计算过程中有一点点误差。但要注意万向锁。