Update on boundary code

FormationController.cs

using UnityEngine;
using System.Collections;

public class FormationController : MonoBehaviour {
	public GameObject enemyPrefab;
	public float width = 10;
	public float height = 5;
	public float speed;
	public float padding;
	
	private float xmin;
	private float xmax;
	
	private bool movingRight = true;
	
	void Start () {
		// calculate the boundaries from teh camera
		float distance = transform.position.z - Camera.main.transform.position.z;
		Vector3 leftMost = Camera.main.ViewportToWorldPoint(new Vector3( 0,0,distance));
		Vector3 rightMost = Camera.main.ViewportToWorldPoint(new Vector3( 1,0,distance));
		xmin = leftMost.x + padding;
		xmax = rightMost.x - padding;
		
		// spawn a new enemy for every position
		foreach(Transform child in transform){
			GameObject enemy = Instantiate(enemyPrefab, child.transform.position, Quaternion.identity) as GameObject;
			enemy.transform.parent = child;
		}
	}
	 
	void OnDrawGizmos(){
		float gizmoWidth, gizmoHeight;
		gizmoWidth = transform.position.x + 0.5f * width;
		gizmoHeight = transform.position.y + 0.5f * height;
		Gizmos.DrawWireCube(new Vector3(0,5,0), new Vector3(gizmoWidth, gizmoHeight,0 ));
	}
	
	void Update () {
		// move the formation
		if (movingRight) { 
			transform.position += Vector3.right * speed * Time.deltaTime;
		}else{
			transform.position += Vector3.left * speed * Time.deltaTime;
		}
		
		// flip the direction if we're outside the boundaries.
		if (transform.position.x < xmin || transform.position.x > xmax){
			movingRight = !movingRight;
		}
	}
}