This is a paid asset, but now you can download Wet Stuff Free.
Detail this asset from Unity Asset Store: Original Link
Wet Stuff v4.1.2 (Latest version)
Wet Stuff v4.1.1
Wet Stuff v4.0.0
Wet Stuff makes it easy to instantly make any surface appear wet; simply place decals into the scene and surfaces within will appear wet. Decals can be configured with a powerful set of tools and animated using timeline to simulate many effects such as water buildup, puddles drying out, slightly damp surfaces and more – all without modifying any textures, materials or shaders.
* Instantly make any surface appear wet
* Easy to use decal system
* VR Support
* Create wet surfaces at runtime
* Automatically creates splashes from particles systems
* Powerful configuration system to create a range of effects such as:
** Rain splatters
** Puddles growing and drying over time
** Leaking Pipes
* Enviro Integration
* Unistorm Integration
Wet Stuff requires cameras using `Rendering Path: Deferred`. If you’re interested in using Wet Stuff with the new HDRP pipeline please contact us.