layer.backfaceVisible < boolean>

Defines whether a layer should be visible when not facing the screen. This is useful when an element is rotated, and you don't want to see its backside.
定义一个图层在不面对屏幕时是否可见。当元件被旋转这是非常有用的，你不希望看到它的背面。

layerA = new Layer
layerA.backfaceVisible = false