Two shader nodes to add rain and water to any surface material! The nodes create raindrop splashes on surfaces above water level and surface ripples and splash rings on the water as well as refraction and discoloring of surfaces below water level, and wetness seeping on surfaces above water level.
You have complete control over the effects, from Size and Intensity to Color, and all animation is derived from a single Time value.
Note: this is a shader solution only. There are no particle systems included.