// 照明效果
        let lightMyNode = SKLightNode()
        lightMyNode.enabled = true
        lightMyNode.lightColor = UIColor.yellowColor()
        lightMyNode.position = CGPoint(x: size.width/2.0,y: size.height/2.0)
        lightMyNode.categoryBitMask = 0xffffffff
        spriteNode1.lightingBitMask = 0x1

        self.addChild(lightMyNode)

如上是照明效果的设置，默认的照明效果很小，所以很有可能位置远一点就一片漆黑了＝＝