TG = <FgBg> ;
TBG = ;
TEMPORARY_BACKGROUND = ;

The temporary background picture which appears behind the track but before the normal background. When the trains start this background is shown in full length. As the trains move, they “eat up” this temporary background, and only the normal background will be visible behind the track, as the front of the trains passes.

The intended use of the temporary background is

Don't forget, that the temporary background is only as high, as the train track - the value of the $IMGY command or IMGY= parameter. If you want to manipulate the catenary above the track, you should give a higher IMGY value, assuring, that the changes are in the track area, and not above it.

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.