I'm stuck. Again. I have imported a few layers from Sketch, an artboard called "artboard" containging a group with an image called "background". The absolute size of this background is 2000x1500. After successfully centering the artboard, I then want to scale it to the screen size of whatever device this is viewed within. But this scaling is not working, even when I use "sketch.background.width = Screen.width" instead.