FadeObjectInOut

Author: Hayden Scott-Baron (Dock)

Description

This allows you to easily fade an object and its children. If an object is already partially faded it will continue from there. If you choose a different speed, it will use the new speed.

It's especially useful for GUI style objects, but can be used on 3D objects in the scene as well.

Updated

Updated 7th March 2013 with the option of pausing before the fade occurs, and a bunch of fixes to 'Fade In On Start'.

Usage

Place this script on the gameobject you wish to fade, and call 'FadeIn()' or 'FadeOut()'. Adjust fading time with 'FadeIn(4.0f)', or by adjusting the public time variable.

Technical Discussion

This requires objects to have materials that allow for alpha transparency.

C# - FadeObjectInOut.cs

/*
	FadeObjectInOut.cs
 	Hayden Scott-Baron (Dock) - http://starfruitgames.com
 	6 Dec 2012 
 
	This allows you to easily fade an object and its children. 
	If an object is already partially faded it will continue from there. 
	If you choose a different speed, it will use the new speed. 
 
	NOTE: Requires materials with a shader that allows transparency through color.  
*/
 
using UnityEngine;
using System.Collections;
 
public class FadeObjectInOut : MonoBehaviour
{
/*
	FadeObjectInOut.cs
 	Hayden Scott-Baron (Dock) - http://starfruitgames.com
 	6 Dec 2012 
 
	This allows you to easily fade an object and its children. 
	If an object is already partially faded it will continue from there. 
	If you choose a different speed, it will use the new speed. 
 
	NOTE: Requires materials with a shader that allows transparency through color.  
*/
 
using UnityEngine;
using System.Collections;
 
public class FadeObjectInOut : MonoBehaviour
{
	// publically editable speed
	public float fadeDelay = 0.0f; 
	public float fadeTime = 0.5f; 
	public bool fadeInOnStart = false; 
	public bool fadeOutOnStart = false;
	private bool logInitialFadeSequence = false; 
 
 
 
 
	// store colours
	private Color[] colors; 
 
	// allow automatic fading on the start of the scene
	IEnumerator Start ()
	{
		//yield return null; 
		yield return new WaitForSeconds (fadeDelay); 
 
		if (fadeInOnStart)
		{
			logInitialFadeSequence = true; 
			FadeIn (); 
		}
 
		if (fadeOutOnStart)
		{
			FadeOut (fadeTime); 
		}
	}
 
 
 
 
	// check the alpha value of most opaque object
	float MaxAlpha()
	{
		float maxAlpha = 0.0f; 
		Renderer[] rendererObjects = GetComponentsInChildren<Renderer>(); 
		foreach (Renderer item in rendererObjects)
		{
			maxAlpha = Mathf.Max (maxAlpha, item.material.color.a); 
		}
		return maxAlpha; 
	}
 
	// fade sequence
	IEnumerator FadeSequence (float fadingOutTime)
	{
		// log fading direction, then precalculate fading speed as a multiplier
		bool fadingOut = (fadingOutTime < 0.0f);
		float fadingOutSpeed = 1.0f / fadingOutTime; 
 
		// grab all child objects
		Renderer[] rendererObjects = GetComponentsInChildren<Renderer>(); 
		if (colors == null)
		{
			//create a cache of colors if necessary
			colors = new Color[rendererObjects.Length]; 
 
			// store the original colours for all child objects
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				colors[i] = rendererObjects[i].material.color; 
			}
		}
 
		// make all objects visible
		for (int i = 0; i < rendererObjects.Length; i++)
		{
			rendererObjects[i].enabled = true;
		}
 
 
		// get current max alpha
		float alphaValue = MaxAlpha();  
 
 
		// This is a special case for objects that are set to fade in on start. 
		// it will treat them as alpha 0, despite them not being so. 
		if (logInitialFadeSequence && !fadingOut)
		{
			alphaValue = 0.0f; 
			logInitialFadeSequence = false; 
		}
 
		// iterate to change alpha value 
		while ( (alphaValue >= 0.0f && fadingOut) || (alphaValue <= 1.0f && !fadingOut)) 
		{
			alphaValue += Time.deltaTime * fadingOutSpeed; 
 
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				Color newColor = (colors != null ? colors[i] : rendererObjects[i].material.color);
				newColor.a = Mathf.Min ( newColor.a, alphaValue ); 
				newColor.a = Mathf.Clamp (newColor.a, 0.0f, 1.0f); 				
				rendererObjects[i].material.SetColor("_Color", newColor) ; 
			}
 
			yield return null; 
		}
 
		// turn objects off after fading out
		if (fadingOut)
		{
			for (int i = 0; i < rendererObjects.Length; i++)
			{
				rendererObjects[i].enabled = false; 
			}
		}
 
 
		Debug.Log ("fade sequence end : " + fadingOut); 
 
	}
 
 
	void FadeIn ()
	{
		FadeIn (fadeTime); 
	}
 
	void FadeOut ()
	{
		FadeOut (fadeTime); 		
	}
 
	void FadeIn (float newFadeTime)
	{
		StopAllCoroutines(); 
		StartCoroutine("FadeSequence", newFadeTime); 
	}
 
	void FadeOut (float newFadeTime)
	{
		StopAllCoroutines(); 
		StartCoroutine("FadeSequence", -newFadeTime); 
	}
 
 
	// These are for testing only. 
//		void Update()
//		{
//			if (Input.GetKeyDown (KeyCode.Alpha0) )
//			{
//				FadeIn();
//			}
//			if (Input.GetKeyDown (KeyCode.Alpha9) )
//			{
//				FadeOut(); 
//			}
//		}
 
}
 
 
 
}