XG = ; XBG = ; GROWABLE_BACKGROUND = ;

The growable background picture, which appears behind the track but before the normal background. The moving trains "eat up" the growable background similarly to the temporary background, and only the normal background will be visible behind the track, as the front of the trains passes. The difference is, that the growable background is at the beginning invisible, and you can let to show it by the animation action GROW. The GROW action controls, how the growable background will be shown. As the name already shows, it can grow - either the can grow from down to up, or the bottom can grow top-down.

The intended use of the temporary background is to show the snow, which grows during the snowfall.

The growable background is not an extra layer before the temporary background, but it is the temporary background layer itself, having special behaviour, so you can define either the TBG= ; or the XBG= ; parameter, but not both.

The format and options of the parameter are explained in detail in the description of the related syntax element <FgBg>.

This parameter is a <PathwayParameters> that is applicable to Sections, Groups, Lines, Scenes, Paths and individual Movements.