How should I Fade a panel?

usingUnityEngine;
usingSystem.Collections;

publicclassFade : MonoBehaviour
{
publicUnityEngine.UI.Image Panel;


voidStart ()
{
Panel = GetComponent<UnityEngine.UI.Image> ();
}

voidUpdate ()
{
Panel.CrossFadeColor (Color.black, 2.0f, false, true);

}


}

When I'm running this code.... there is error MSG Like this "
NullReferenceException: Object reference not set to an instance of an object
Fade.Update () (at Assets/Script/Fade.cs:16)"

I already Put a UI Panel object.. what's wrong??

 

This script is attached to a GameObject with an Image? Must not be?

 

http://youtube.com/watch?v=MkoIZTFUego

 

Doesn't get much cleaner than that.

 

Thanks! I know you have strict standards on random YouTube tutorials. Glad I measure up.

 

I put yours on my 'approved' list at work. I hope you continue your ones on general concepts.

 

hi, just use this script i created , it looks complex but it is actually highly optimized , use show and hide functions to fade in and fade out, have fun : )


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

public class UI_Fader : MonoBehaviour {

public bool startAsHidden;
public float fadeSpeed = 5f;

List<Color> imageInitialColors;
bool hide = false,fullyOptimised;
int OptimisationInt = 0;


public void Hide()
{
if(OptimisationInt != -1)
{
hide = true;
setUnOptimised ();
}
}

public void Show()
{
if(OptimisationInt != 1)
{
hide = false;
setUnOptimised ();
}
}

void setUnOptimised()
{
fullyOptimised = false;
OptimisationInt = 0;
}

void Awake()
{
imageInitialColors = new List<Color> ();
foreach(Image image in GetComponentsInChildren <Image>())
{
imageInitialColors.Add (image.color);
}
foreach(Text txt in GetComponentsInChildren <Text>())
{
imageInitialColors.Add (txt.color);
}

if(startAsHidden)
{
foreach(Image image in GetComponentsInChildren <Image>())
{
image.color = new Color (image.color.r, image.color.g, image.color.b, 0);
}
foreach(Text txt in GetComponentsInChildren <Text>())
{
txt.color = new Color (txt.color.r, txt.color.g, txt.color.b, 0);
}

OptimisationInt = -1;
fullyOptimised = true;
}
}


void Update()
{
if(!fullyOptimised)
{
if(OptimisationInt == 0)
{
if(hide)
{
foreach(Image image in GetComponentsInChildren <Image>())
{
image.color = Color.Lerp (image.color, new Color (image.color.r, image.color.g, image.color.b, 0), fadeSpeed * Time.deltaTime);
}

foreach(Text txt in GetComponentsInChildren <Text>())
{
txt.color = Color.Lerp (txt.color, new Color (txt.color.r, txt.color.g, txt.color.b, 0), fadeSpeed * Time.deltaTime);

if (txt.color.a < 0.05f)
OptimisationInt = -1;
}
}
else
{
int i = 0;
foreach(Image image in GetComponentsInChildren <Image>())
{
image.color = Color.Lerp (image.color, imageInitialColors, fadeSpeed * Time.deltaTime);
i++;
}
foreach(Text txt in GetComponentsInChildren <Text>())
{
txt.color = Color.Lerp (txt.color, imageInitialColors, fadeSpeed * Time.deltaTime);
i++;

if (txt.color.a > 0.95f)
OptimisationInt = 1;
}
}
}
else
{
if(OptimisationInt == 1)
{
int i = 0;
foreach(Image image in GetComponentsInChildren <Image>())
{
image.color = imageInitialColors ;
i++;
}
foreach(Text txt in GetComponentsInChildren <Text>())
{
txt.color = imageInitialColors;
i++;
}
}
else if(OptimisationInt == -1)
{
foreach(Image image in GetComponentsInChildren <Image>())
{
image.color = new Color (image.color.r, image.color.g, image.color.b, 0);
}

foreach(Text txt in GetComponentsInChildren <Text>())
{
txt.color = new Color (txt.color.r, txt.color.g, txt.color.b, 0);
}
}

fullyOptimised = true;
}
}

}

}

 

That is really pretty heavy, not sure how it could be called optimized. You are not caching, and along multiple foreach loops of getcomponents on stacks of children, lerping the whole color instead of just the alpha. I'm not sure ther is a less optimal way to do it.

Just use canvas group.

 

In what world is calling GetComponent in Update highly optimised?