New guy on the forum and on after effect so don't be too harsh ! I have a project for school where I have to do a 30s animation and on one of my sequence I have a marble that makes loops and then goes off the screen. My problem is that when the marble do the loops it is in front of the rails but then I need to make it pass behind for it leave but I don't seem to find the way to make it pass behind and I didn't find any good solution at the moment.
but technically/by logic - it can't be in front of other rails, when going deeper down into Z space? ☺
Anyways, if you really need to put it down only in the last part of rail - ctrl+shift+D (WIN) or cmd+shift+D (MAC) splits the layer. Do this split at the time when marble reaches side of the last rail's circle. Move marble layer to the bottom of the layers stack.
In addition, duplicate the rail and mask out everything except the last rail line. That way, place it under the marble and you will be good to go.
Just found a solution, I just separated all the rails in photoshop and made them appear and disappear at different times and layer in my animation and it works great but thanks for your tips I'll remember it !