Potential Idea For Wet Surfaces

This is completely untested, since I have little to no experience with graphic programming. The idea is that you can take a texture with a normal and specular map and modify it so that it appears as though a surface is wet (either all across it or only in certain parts) by modifying the normal and specular. One could then apply a colored texture to it, and the specular would make it shiny, whist the normal change would make it appear to actually be on the surface, rather than completely flat. With some fancy calculations this could potentially have a flowing effect, or drying off effect, such as when a character walks out of a pool onto the ground, it would leave footprints that would dry away. In the context of horror games, it could potentially be used for blood effects.