Here are a few comparison shots. Below is a plane with some basic sine wave animation. Besides the SSAO UDK and UE4 have, there really isn't much in terms of lighting. Its just all very flat looking.
This is a slight change from my earlier method, in that i am building the normals outside the function. This allows me to add multiple offsets together and rebuild the normals for all of them at once. The G_Waves_Fourier function employs this by using 3 G_Waves_Normal functions and adding them together.