Delayed activation of GameObjects in Unity3D

DelayedActivation.cs

using System.Collections;
using UnityEngine;

// @kurtdekker - delayed-activates things in your scene:
// To use:
//	1. put this script on fresh blank GameObject
//		- NOT the same one that you are delayed-activating
//		- NOT a child of the one(s) you are delayed-activating!
//		- MAY be above other child GameObjects you activate (eg at top of hierarchy)
//	2. set the amount of delay in TimeToDelay field
//	3. drag the GameObject(s) you want to delay-activate into the TargetsToActivate slot
//	4. be sure to disable the GameObject(s) you want to activate later!!
//
// WARNING: make sure scripts on your target GameObject(s) are happy to be
// turned off and then turned back on; this script cannot know that.

public class DelayedActivation : MonoBehaviour
{
	[Header( "How long to wait before delay?")]
	public float TimeToDelay;

	[Header( "If you have one thing to activate")]
	public GameObject TargetToActivate;
	[Header( "If you have many things to activate")]
	public GameObject[] TargetsToActivate;

	void Reset()
	{
		TimeToDelay = 2.0f;		// handy default
	}

	IEnumerator Start ()
	{
		yield return new WaitForSeconds( TimeToDelay);

		SetActiveHelper( true);
	}

	void SetActiveHelper( bool active)
	{
		if (TargetToActivate)
		{
			TargetToActivate.SetActive( active);
		}
		if (TargetsToActivate != null)
		{
			foreach( var target in TargetsToActivate)
			{
				if (target)
				{
					target.SetActive( active);
				}
			}
		}
	}
}