I've made a comp consisting of three layers. It's just a dotted line (with trim paths) and two arrowheads following the line.
I've brought that comp into my main comp and it looks great.
But now I want that dotted line comp to "follow" the background as it moves (I'll parent it to a null object). But when I turn on 3d Layers for that dotted line comp… it goes crazy! Bouncing around all over the place.