I have done some searching but haven't really been able to find what I'm looking for, mostly because I'm not sure what to call it. So I figured I'd make a post (my first, though I have lurked for years).
I have a null with several objects (buildings) linked, and have animated the null along the x. I'm trying to add some hills and a sun in the background, and I want them to move along the x with the same dynamics, but not at the same speed- rather, slower, at a set fraction (to achieve a sense of perspective/scale/distance).
I imagine that it would be possible to write a script in the position value of each of the background layers to create that dynamic, where the X value changes (accounting for eases done in the graph editor) are interpreted at a smaller scale, but I'm not sure where to start. The only expression in my repertoire is wiggle right now (though this project has thrown into sharp relief my need to develop that further!).