Moving 2D Backgrounds in Unity

In my Unity 2D Game, I need to move some items in the background, including:

• Pavement
• Street Lights
• Buildings

Then it feels like the player is moving. But actually, the items are moving backward.

Have a look at this video:

It'd be great if we automatically spawn these items & move. That's where we can get some help from a C# script. Here's how to do that:

• Create a script called "InfiniteMovingBelt.cs" in your project
• Then add the following content

	using System.Collections;
	using System.Collections.Generic;
	using UnityEngine;
	public class InfiniteMovingBelt : MonoBehaviour
	{
	public GameObject item;
	public float speed = -1f;
	public float spawnOffsetFromScreen = 1f;
	public float destroyOffsetFromScreen = 1f;
	public float spawnDistance = 5f;
	public float spawnProbability = 1f;
	private readonly List<GameObject> instances = new List<GameObject>();
	void Start()
	{
	// Create the instance
	MakeInitialSpawning();
	}
	void Update()
	{
	foreach(GameObject instance in instances.ToArray())
	{
	if (CanDestroy(instance))
	{
	Destroy(instance);
	instances.Remove(instance);
	continue;
	}
	Vector3 originalPos = instance.transform.position;
	float posX = originalPos.x + (speed * Time.deltaTime);
	Vector3 newPosition = new Vector3(posX, originalPos.y, originalPos.z);
	instance.transform.position = newPosition;
	}
	SpawnIfNeeded();
	}
	private Vector3 GetScreenSize()
	{
	var screenSizePixels = new Vector3(Screen.width, Screen.height, 0);
	return Camera.main.ScreenToWorldPoint(screenSizePixels);
	}
	private bool CanDestroy(GameObject i)
	{
	Vector3 screenSize = GetScreenSize();
	return i.transform.position.x < GetDestroyX();
	}
	private void SpawnIfNeeded()
	{
	GameObject last = instances[instances.Count - 1];
	float diff = GetSpawnX() - last.transform.position.x;
	if (diff >= spawnDistance)
	{
	SpawnWithProbability(GetDefaultStartPos());
	}
	}
	private float GetSpawnX()
	{
	return GetScreenSize().x + spawnOffsetFromScreen;
	}
	private float GetDestroyX()
	{
	return -(GetScreenSize().x + destroyOffsetFromScreen);
	}
	private GameObject SpawnWithProbability(Vector3 startPos)
	{
	bool canSpawn = Random.Range(0f, 1f) < spawnProbability;
	if (canSpawn)
	{
	return SpawnItem(startPos);
	}
	return SpawnItemAndHide(startPos);
	}
	private GameObject SpawnItem(Vector3 startPos, bool addToFront = false)
	{
	GameObject instance = Instantiate<GameObject>(item, startPos, Quaternion.identity);
	if (addToFront)
	{
	instances.Insert(0, instance);
	} else
	{
	instances.Add(instance);
	}
	return instance;
	}
	private GameObject SpawnItemAndHide(Vector3 startPos)
	{
	startPos.y = 10;
	GameObject instance = Instantiate<GameObject>(item, startPos, Quaternion.identity);
	instances.Add(instance);
	return instance;
	}
	private Vector3 GetDefaultStartPos()
	{
	return new Vector3(
	GetSpawnX(),
	gameObject.transform.position.y,
	gameObject.transform.position.z
	);
	}
	private void MakeInitialSpawning()
	{
	Vector3 startPos = GetDefaultStartPos();
	while(startPos.x > GetDestroyX())
	{
	SpawnItem(startPos, addToFront:true);
	startPos.x -= spawnDistance;
	}
	}
	}

view raw InfiniteMovingBelt.cs hosted with ❤ by GitHub

• Then Create an "Empty Game Object" and add this script

After that, customize the parameters of this script as shown in the above video.

Better Solution

Since this might be a common task in 2D games, I think there is a much better solution than this. If you know a better solution, just let me know.