Hi all! consider the below: the opposition trooper moves from A to B over the parapet/barrier. there is a friendly trooper viewing from below. Is there any point in the opposition troopers movement that they do not have cover?
When the model passes over the obstacle, it passes OVER the obstacle Put a Silouhette there and check, it's the only way to know... But remember, a model in a higher position like that will always have a part of its Silouhette obscured by the building. Something like this:
To funny answer if there is cover we would need to check line of sight from the attacking trooper. Cover applies if Terrain that the target is in contact with covers any part of their silhouette. If all of the silhouette can be seen by the attacker after the vault then no cover, if any of the silhouette is obscured then cover. In this case if the attackers was tall enough or far enough away there may be the possibility of a shot at no cover.