HowTo/Bridge/adjust-cross-section-to-ground
From TrainzOnline
adjust-cross-section-to-ground
This tag is compulsory with this track container
If this boolean value is set (1), the track mesh is distorted across its X axis to follow the ground plane upon which it rests. If clear (0) the mesh will assume the ground height from the center point. This setting has no effect on vertices which are within the adjust-height-to-ground-threshold range.
