not sure if you need to there Michael 
@riccardosuardi This is an option using a scroll listener on scene load.
Basically, it looks for the difference between the window's top and a specific trigger element's top value (could be a number instead) and when they meet it fires the timeline (that is a simple reveal up of the footer elements) and also via javascript sets the style attributes "fixed" and "translateY" which enables the grouped footer element to stay fixed to the bottom. (a calculation of the window's inner height and the footer element's height)
fixedFooter-vDBear.hype.zip (15.3 KB)