Unity Parallax Effect

C# script to make parallax effect.

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

// ? 2017 TheFlyingKeyboard and released under MIT License
// theflyingkeyboard.net

public class ParallaxEffect : MonoBehaviour {
    [SerializeField] [Tooltip("From closest to furthest")] private List<Transform> backGround;
    [SerializeField] [Tooltip("From closest to furthest, closest objects should have biggest multipliers")] private List<float> speedMultipliers;
    [SerializeField] private float smoothing = 0.75f;

    [SerializeField] private Transform cameraToUse;
    private Vector3 previousCameraPosition;

    private Vector3 offset;

    void Start()
    {
        previousCameraPosition = cameraToUse.position;
    }

  void FixedUpdate () {       
        for (int i = 0; i < backGround.Count; i++)
        {
            offset = (previousCameraPosition - cameraToUse.position) * speedMultipliers[i];

            backGround[i].position = Vector3.Lerp(backGround[i].position, backGround[i].position + offset, smoothing * Time.deltaTime);
        }

        previousCameraPosition = cameraToUse.position;
    }
}