Proper transition between SpriteKit Animations

问题

I have an idle player animation and I want to do a smooth transition between some animations. The idle animation is the default one and from that transition I want to be able to switch to another state(let's say fight) and then back to idle. The code for the idle character animation is currently like :

self.addChild(playerAnimation)
playerAnimation.runAction(SKAction.repeatActionForever(
            SKAction.animateWithTextures(playerAnimationManager.idleManAnimation.textureArray, timePerFrame: 0.1)))

Now, this is scheduled to go on forever for now, but I would need to intercept it and add a new animation on top of that (which is the same character, in a new state). I was thinking that I should stop the idle animation, switch to the new one and then back to idle when finished but I am not convinced that this is the best way of chaining animations and I haven't really found a good resource explaining how to go about it.

Any suggestions ? Thanks !

回答1:

Depending on how short your texture array is, you might be able to do this.

I will try to explain without code seeing how I use objective C and you use Swift

First make a property or variable that can be called by any subroutine in this class file. It should be Boolean and should be set to NO. You could call it idleFlag.
Next make a method that changes the animation to fight mode. This change would be by removing the idle animation and replacing it with the fight animation. This method also set's idleFlag to NO. Let's call the method "beginFightAnim"
And last, in your repeatActionForEver idle animation, right after your animateWithTextures animation, add a runBlock animation. In this block define a static variable (one that will be remembered in the calling of the block over and over) and increment it by +1, add an "if statement" that looks something like this -> if (my_static_var == number_of_frames_in_texture_animations && idleFlag). And in the "if statement" set the static variable to 0 and call "beginFightAnim"

After this all you have to do to change the animation is set idleFlag to YES.

Hope it works!

If you have any problems, please comment below.

回答2:

I want to do a series of examples to make it easier to understand the matter. Suppose you have your node called playerAnimation, a typical atlasc with a plist where you have

player-idle1.png
player-idle2.png
player-idle3.png
...

If you want to intercept in real-time your animation to know what frame is running in that moment you can do:

override func update(currentTime: CFTimeInterval) {
   if String(playerAnimation.texture).rangeOfString("player-idle") != nil {
      print(String(playerAnimation.texture))
   }
}

At this point, after you have assigned a "key" to your action (withKey:"idleAnimation") you could stop your specific idle action when you preefer to start the other next animation.

Another good thing is to build a structure to know everytime your player status and modify this variable each time you launch a new action or animation:

enum PlayerStatus: Int {
    case Idle = 1
    case Fight = 2
    case Run = 3
    case Jump = 4
    case Die = 5
    ...
}

var currentStatus: PlayerStatus!

来源：https://stackoverflow.com/questions/38557040/proper-transition-between-spritekit-animations

标签

swift

xcode

sprite-kit