If you look up for rain systems you get to see most of the time that people use particle effects for that.
But then I wonder is it not heavy and bad for performance to have thousands of rain particles in the map?
I heard some people suggest to attach the particle system to the character so you don’t have to generate a lot of particles. And that could work for single player.
But let’s say you have a game like PUBG where the map is huge and it is multiplayer and you need to have rain everywhere on the map. What would be the most efficient way of doing this, is there actually other ways of making a rain system without particles?
Particle systems are pretty efficient for rendering hundreds or thousands of particles. They’re not expensive like Actors are. You do need to exercise some control and employ tricks like attaching the particles to the character but otherwise you should be OK (just don’t go overboard and consider if you really need physics collisions etc).
One other way of rendering the rain would be to do it all in a post process, but you probably won’t get a very satisfying result (although people more skilled than me might have more luck).
In terms of a multiplayer, you could just attach PFX above each player and optimise by only rendering the players own rain PFX. You might need to turn other on / off or move the player PFX depending on the camera location but the key thing is to remember that it only needs to look like it’s raining from the one camera the player is looking at (true even if you have 100’s of players because each is running their own client, and it’s only on their client that they need to see the rain where they are).