Hi all. I'm working on a "fresh out of the shower look " displacement map to work on all poser figures and objects.

So far i have the result in the render window but need to know how to make it more procedural so that the drops will trickle downwards and simulate gravity.. The node setup to make the water drops seems to work  fairly well although it still needs a little refraction but the gravity effect is eluding me..Any help on this would be very welcome.