Not sure if it is the original but the source where I first saw this rain effect was on ShaderToy - The Drive Home by Martijn Steinrucken aka BigWings[1]
The accompanying video tutorial[2] is super interesting too as well as the HN discussion at the time [3].
It has already been posted by jeffschofield, but the original is here[1], along with a brief article breaking down the effect[2].
The one you posted is in many ways nicer though due to it all being a single shader, however it has the downside of the drops not interacting with each other.
Hahha i was like. This is the "drive home"
Martijn is an exceptional explainer I like his channel a lot. A great resource if you want to start programming shaders.
The one you posted is in many ways nicer though due to it all being a single shader, however it has the downside of the drops not interacting with each other.
[1] https://tympanus.net/Development/RainEffect/
[2] https://tympanus.net/codrops/2015/11/04/rain-water-effect-ex...