Unfortunately it doesn't work the way I would wish it to work, since the fill is displayed in the way I l've presented on the s reenshots. This concerns the section views, not the plan views. And does not affect the composite structures. The slab I have modelled is a single layered one.
Can you think of what makes this work? 🙂 in the video, they are both moved together up and down in a SECTION view. One has the Building Material Fill Orientation set to "Fit to Skin", the other Building Material Fill Orientation is set to "Project Origin" . In case the video does not work or some, the Fill/Building Material in one slab changes as the slabs are moving up and down, the other one does not. This is controlled by Building Material settings.
Oh, that is an actual slab element not a 2D fill... Doesn't that setting require the use of composites? Only walls in Plan do not "require" this. So the issue here would be that Ged has used a Basic Slab rather than a Single Layer Composite?