SKSpriteNode will not fadeInWithDuration using SKAction in sequence Sprite Kit

Question

Im running 3 SKActions in a sequence, the 1st two run just fine but the fadeInWithDuration does not fade in the node, the node just gets added right away when the view loads. Do I have to set the the initial alpha channel for the node to 0? Can someone help with problem?

- (void)setUpButtonStart
{
    SKSpriteNode *buttonStart = [SKSpriteNode spriteNodeWithImageNamed:@"start"];
    buttonStart.name = @"buttonStart";
    buttonStart.position = CGPointMake(900,50);
    [self addChild:buttonStart];

    SKAction *wait = [SKAction waitForDuration:2.5];
    SKAction *readIntro = [SKAction playSoundFileNamed:@"intro.mp3" waitForCompletion:NO];
    SKAction *fadeIn = [SKAction fadeInWithDuration:1.0];

    SKAction *sequence = [SKAction sequence:@[wait, readIntro, fadeIn]];

    [buttonStart runAction: sequence];
}

I would give that a try, set alpha to 0 before running the fade action. — CodeSmile, Feb 06 '14 at 14:42

Batalia · Answer 1 · 2014-02-06T16:09:52.973

18

As stated in the documentation, the fadeInWithDuration action changes the alpha property of the node from its current value to 1.0 (100% opacity).

That's why you're not seeing the fade-in - your action will not actually do anything, since the default alpha value of a node is 1.0, it will go from 100% to 100%.

As Steffen has suggested in his comment, all you need to do is set buttonStart.alpha = 0.0 before the action is executed.

edited Feb 06 '14 at 16:09

answered Feb 06 '14 at 16:03

Batalia

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This is the best answer, I think you can accept it as a best answer ;) – BSevo Feb 07 '14 at 09:32
Yes that works great, thanks for clearing that up :) – Stefan Feb 07 '14 at 16:43
What if you don't want to fade all the way to alpha = 1? What if you only want to fade until alpha = .8? – zeeple Apr 08 '14 at 05:46
@user1639164 you don't use fadeInWithDuration in that case, but instead you go with [SKAction fadeAlphaTo:.8 duration:(NSTimeInterval)] – Batalia Jul 29 '14 at 13:15

SKSpriteNode will not fadeInWithDuration using SKAction in sequence Sprite Kit

1 Answers1