SpriteKit中帧错误的动画？

Question

有时在SpriteKit中，帧的动画不起作用：有一个白色矩形，然后是来自地图集的图像，依此类推。当我再次停止并运行时，动画适用于每一帧。你知道为什么会这样吗？

框架是文件夹中的常规png，我手动添加“.atlas”并将其拖动到XCode。这是代码：

var ball : SKSpriteNode!
var ballTurn : [SKTexture]!
ball = SKSpriteNode(texture: ballTurn[0])
ball.position = CGPoint(x:CGRectGetMidX(self.frame), y:CGRectGetMidY(self.frame))
addChild(ball)

turningBall(ball, textures: ballTurn, str:"ballTurn")

func turningBall(theNode: SKSpriteNode, textures: [SKTexture], str:String) {
    theNode.removeAllActions()
    theNode.runAction(SKAction.repeatActionForever(
        SKAction.animateWithTextures(textures,
            timePerFrame: 0.05,
            resize: false,
            restore: true)),
        withKey:str)
}
//the method to generate the frames from Blender
func generatorFrames(atlas:SKTextureAtlas, str:String) -> [SKTexture]{
    var frames = [SKTexture]()
    let count = atlas.textureNames.count
    for var i=0; i<count; i++ {
        var theName = ""
        if i < 10 {
            theName = str+"000\(i)"
        } else {
            theName = str+"00\(i)"
        }
        frames.append(atlas.textureNamed(theName))
    }
    return frames
}