Thanks Joe and Dave. Joe, I tried to make a brush in Illustrator, but I’m guessing the grass vector was too complex because it wouldn’t let me. The image of the grass layer was actually 7 sections pieced together. What I ended up doing was taking each section and applying an envelope warp then I just adjusted the anchors and handles to match the curve of the hills. It was time consuming, but it came out how I had hoped. I’m just surprised that After Effects doesn’t have a “form to path” feature for images. I know you can do it with text, but doing it for images seems to be a feature that could be added for CS7 (unless it already exists and I can’t find it).
Anyway, here is a screenshot of what the rolling hills look like now.
https://722productions.com/wp-content/uploads/2013/03/AE-Sample-2.png
Thanks again for your kindness to respond.
Jason