Wavy Grass in UDK

Mike had the idea of doing grass inspired by Viva Piñata. It's a little hard to tell from screenshots of the game but if you zoom in, the grass is actually made of shells like the fur in SOTC. http://youtu.be/taIuZAGOFTo (see video description for a more in-depth look at fur)
Since the Vertex Color was already filling each shell in a gradient from top to bottom, I had the idea to use the same colors to drive an offset and make it look like it's waving around.

Please note that everything was made with placeholder assets. I haven't gotten to refining the art in my level yet. I think this will look really nice once I swap out my leaves texture for a proper grass alpha.
Because all 3 Vertex Color channels are storing the same values, this doesn't really matter, but I meant to append R and G, not sure how B ended up getting plugged in there.