Hello guys I need your help once again. I need to make rain for my game I was thinking on making big sheets and applying a raining panner material to it. My problem is that my map is rather large. Will there be lots of issues performance wise to my game having this many planners around? Also how would I go about making the buildings look wet without changing the materials directly. Could I use decals. I really don’t know how to approach this.
Look forward to your suggestions.
I gonna give you a tip not only for that but graphical design overall.
Think your self as illusionist, it does not matter what you see whats matter is what player see. So if you have large area you dont need rain everywhere, only where player is.You could look on snow particules in effects cave it might give inspration for rain.
As for makeing things wet you can use material parameters which let you change look of material on the fly.
OK. Having looked at the snow particles. I still don’t see how to continue. I have a vast open world and when it rains I don’t want the rain to be visible. Would the answer be to have collisions on a large rain particle and attach to player somehow. Then once I enter the bldg the collision should stop the rain coming through? Am I on the right track? I know how to build these things I think just not sure how to implement 
Thanks for your help
ok having looked at the effects cave the one actor I saw that seems to have the most impact visually to me as being in a snow storm was P_Blizzard6. Which is a particle emitter. I would recommend looking though at the Solus tutorials by Hourence as he covers some stuff that may give you inspiration. As for wet materials I would look at the Reflections example it shows some materials doing something like that if I remember right.
Hope this helps
Exacly Houfences made rain following player
This is less of a specific implementation answer and more of a “you might find this of interest” answer. It’s a series of articles about Remember Me. Part B is about rain implementation and Part C is about wetting in general.
As far as making the buildings look wet, since I just mentioned this in a forum post earlier, have a look at the Blueprint Communication level in Example Content. Last example, 3.3, has three spheres you can spray water (or fire) on, and the metal and wood spheres look wet when you do so.
Horrences system is not applicable for games with multiple players however. Since he is creating a volume centered on the player, imagine what that would look like if you had say 50 players on the server? Would each one have his/her own volume following them around? What if two volumes overlap? How is the world affected if NOT in the volume? Obviously, there are work-around ideas to answer all of these questions.
I would (on a large scale map) create a volume of rain (and sounds, and material effectors) that you can then move around the map as you see fit (like a natural storm cloud floating over your map that drops the rain on anything below it). This way, there is only ONE for the whole map and you could easily integrate lots of players (as in either they are in the volume or they are not). This is a more advanced system, but it could be done… even through blueprints.
In that case activate rain only on local player