Making snow&rain "affect" some things?

[Amnesiaplayer]

Thanks everyone for help, I think i'll stick with the untrealistic idea.
Didn't know you needed to do THIS on hpl2 lol.
Btw, idea is from another engine, I'm also creating something else, but I think that that engine stays updated until this year lol. but from there, I could create THAT, where you can place rain, and make the rain stop if it collides something so tried to do the same thing to amnesia