This video shows the iWave method (Tessendorf 2004) simulating a droplet in shallow water. Collisions (ripples) are calculated from the droplet. Ambient waves are also generated in the water using an FFT over phase/amplitude data generated from an oceanographic model. The video shows the final rendering, followed by a hidden-line wireframe rendering.
I programmed a custom simulation plugin (http://github.com/sdao/iWaveOcean) in 3ds Max, and I rendered with Mental Ray, using caustics.