What I'm trying to do is draw a line coming from the top of the screen to the bottom (using trim paths) and apply turbulent displacement to the bottom half of the line only. At the moment is applies the effect to the whole line, and using a mask doesn't allow me to keep the two sections joined together at the half point (the turbulence effect breaks the line and doesn't look like one object)
Just looking for a quick fix on how to solve this problem?
Create a precomp with Fractal Noise in the lower half and a flat grey at the top. (Two solids, one with Fractal Noise at the bottom and one with Linear Wipe at the top.)
Use that precomp to drive a Displacement Map effect on your line.
Thanks very much!