Making snow&rain "affect" some things?

[Traggey]

Alright first of, rain effects are always expensive, but no Spelos it won't be THAT preformance heavy, I was doing it way back in the Unreal 2 days.

So here's the rundown, the problem with making a particle effect like this is that HPL will not alow you to do physics interaction on the effects and call events from it ( as far as I can recall anyway ), in a game engine like unreal what I would do is calculate hit detection on each particle and when it hits the ground, kill the particle and spawn another one which would be the splash impact.

Now rendering houndreds of these particles at once? Can become a tad expensive, that's why we don't!

You only need them rendering in an area around the player, when I do this I usually attach the particle system slightly offset to the front of the player, so that they can still see it if looking to the left or right on the screen, but nothing will be rendering behind the player, as the they will never be able to look at that anyway.



Then we attach what I call a rain cylinder to the player aswell, this is a big cylindrical mesh with inwards facing polygons, to this mesh we apply a material of falling water. Scale the cylinder up and it will become a nice and cheap way of faking far away rain, to make your bad weather seem a bit more impactfull.

Here's a little gif from a game I've been making for fun, demoing this kind of effect, I have not yet implemented the far away rain cylinders, but the particle system is here.



So basicly, look around if you can generate events from particle collision, if not, you're pretty much screwed.