LeanDirection

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


public class MoverNoise : MonoBehaviour {

    public float NoiseAmntZ = 1;
    public float NoiseSpeedZ = 1;
    public float NoiseRandZ = 1;
    public float RotMag = 10;
    public float LeanAmnt = 45f;
    private Vector3 LastPosSave;

    void Update()
    {
        float RandomZ = (Mathf.Sin(Time.time * NoiseSpeedZ) + Random.Range(-NoiseRandZ, NoiseRandZ)) * NoiseAmntZ;
        transform.position = new Vector3(0f, 0f, RandomZ);
        Vector3 VelocityCalcAmnt = transform.position - LastPosSave;
        float VelocityAmnt = (VelocityCalcAmnt.magnitude);

        Debug.Log(VelocityAmnt);

        //transform.Rotate((transform.right  * (VelocityAmnt.magnitude*RotMag)) * Time.deltaTime, Space.World);
        Vector3 euler = transform.localEulerAngles;

        euler.z = Mathf.Lerp(euler.z, transform.rotation.z, 2.0f * Time.deltaTime);
        transform.localEulerAngles = euler;
        LastPosSave = transform.position;

    }
}

///////////////////////////////////////////////////////////

/// <summary>
     /// Tilts a rotation towards a velocity relative to referenceUp
     /// Example:
     /// myTransform.rotation = TiltRotationTowardsVelocity( myCleanRotation.rotation, Vector3.up, velocity, 20F );
     /// </summary>
     /// <param name="cleanRotation"        >Target rotation of the transform, maybe your transform is already looking at something, you don't want to loose this alignment</param>
     /// <param name="referenceUp"        >The up Vector, mostly, this will be Vector3.up, if your gravity is pointing down</param>
     /// <param name="vel"                >The velocity vector that is meant to cause the tilt</param>
     /// <param name="velMagFor45Degree"    >A velocity with a magnitude of velMagFor45Degree will yield a 45degree tilt</param>
     /// <returns>returns currentRotation modified by a tilt</returns>
     public static Quaternion TiltRotationTowardsVelocity( Quaternion cleanRotation, Vector3 referenceUp, Vector3 vel, float velMagFor45Degree )
     {
         Vector3 rotAxis        = Vector3.Cross( referenceUp, vel );
         float    tiltAngle    = Mathf.Atan( vel.magnitude /velMagFor45Degree) *Mathf.Rad2Deg;

         //    Helping tp visualize, https://docs.unity3d.com/ScriptReference/Vector3.Cross.html
             //    Debug.DrawRay( myTransform.position, referenceUp,    Color.yellow    );    //leftHand thumb
             //    Debug.DrawRay( myTransform.position, vel,            Color.green        );    //leftHand index
             //    Debug.DrawRay( myTransform.position, rotAxis,        Color.cyan        );    //leftHand middle

         return Quaternion.AngleAxis( tiltAngle, rotAxis ) *cleanRotation;    //order matters
     }