This tutorial shows how to simulate raindrops hitting a puddle using dynamic paint:
It works fine on Blender 2.79.
But when rendered in Blender 2.8 2018-10-23 07:41 the waves do not work.
The waves appear in the Viewport render preview, but not in the final render.
Tried on Windows 10 and Mac 0S 10.13.6
screenshot of viewport render