Infinite scrolling sprite background in Unity3D

TiledSpritesInfinite.cs

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

// @kurtdekker
// To use:
//	import a repeating sprite, FullRect
//	drop it on a SpriteRenderer GameObject
//	drop this on that same SpriteRenderer you want to be infinitely tiled
//
// Now just move the orthographic camera using the editor Transform controls

public class TiledSpritesInfinite : MonoBehaviour
{
	Camera theOrthoCamera;
	SpriteRenderer theRenderer;
	Sprite theSprite;

	float pixelsPerUnity;

	Vector2 SpriteSize;		// world size of the sprite

	void Start()
	{
		// You may replace this with an explicit reference
		// to the camera you want track
		theOrthoCamera = Camera.main;

		// ensure ortho
		theOrthoCamera.orthographic = true;

		theRenderer = GetComponent<SpriteRenderer>();
		// ensure tiled
		theRenderer.drawMode = SpriteDrawMode.Tiled;
		theRenderer.tileMode = SpriteTileMode.Continuous;

		theSprite = theRenderer.sprite;
		// how big is this thing?
		pixelsPerUnity = theSprite.pixelsPerUnit;
		Rect r = theSprite.rect;

		SpriteSize = new Vector2( r.width / pixelsPerUnity, r.height / pixelsPerUnity);
	}

	void Update()
	{
		// take current camera position
		Vector2 camXYPosition = theOrthoCamera.transform.position;

		// quantize by sprite "cells"
		int camCellX = (int)(camXYPosition.x / SpriteSize.x);
		int camCellY = (int)(camXYPosition.y / SpriteSize.y);

		// chunk us along to the proper cell we need to be to stay with camera
		transform.position = new Vector3(
			camCellX * SpriteSize.x,
			camCellY * SpriteSize.y,
			transform.position.z);

		// adjust our tiled size
		float height = theOrthoCamera.orthographicSize * 2;
		float width = (Screen.width * height) / Screen.height;

		// verge / margin beyond
		height += SpriteSize.y * 2;
		width += SpriteSize.y * 2;

		// drive the size
		theRenderer.size = new Vector2( width, height);
	}
}