Dinamic Weather Sistem.

[maximsubbota]

Hi to everyone.
I have a problem, I don't know how can I create a dinamic weather sistem for an enviorment.

I know how to do day and night, rain, fog..
But my problem its that I don't know how can I make a rainy day, a foggy day Randomly.

Please I need help or a tutorial.
Thanks to all from Spain

[Chosker]

well day/night, rain and fog can be done in the editor. a random way to do this however, might need unrealscript work.
you might however be able to do it in the editor via Kismet. if you already have rain and fog in ways that you can activate/deactivate them, you may be able to set some random numbers that refresh every 'X' condition and if it meets any 'Y' criteria activate the rain, etc.
another matter is how you've handled your clouds, hopefully you're already able to simulate a cloudy day with them because rain without gray coulds would look weird.

perhaps if you explain a little more how your day/night, rain, clouds, etc, systems work we could have a better idea on how to make them work in a more unified way

greetings from Spain (bcn) to you. counting me you're the 3rd one I've seen around here

[Wyldhunt]

Well, the clouds would be fairly easy. Just make sure that you have parameters in the material and run the sky off of an instance of your material so that you can directly control your parameters via script(Or, maybe kismet). You can control everything you need that way. Add some to Opacity. Maybe darken the diffuse tint. Maybe reduce your UV's in your TexCoord so that the individual clouds appear larger... You can even replace entire 2dtextures to use an entirely different set of clouds as long as you're using parameters for them. So, that part will probably be the easy part. If you're using the rain system that's built out of a bunch of intersecting planes with a panning rain texture, then you can use instancing and parameters to control that as well. I've never done anything with particles, so I'm not sure if they are as straight forward to control. I'm guessing that they should be though.
Mostly, you need to figure out the math of how to decide what the weather is like, and figure out where and when to run that check. Changing stuff should be easy once you get there.

If you haven't discovered instanced material parameters yet, check:
http://udn.epicgames.com/Three/Mater...UserGuide.html
http://udn.epicgames.com/Three/InstancedMaterials.html
http://udn.epicgames.com/Three/Mater...eConstant.html
http://udn.epicgames.com/Three/Insta...meVarying.html

For the parameters that allow control, check:
http://udn.epicgames.com/Three/Mater...namicParameter
http://udn.epicgames.com/Three/Kisme...erial Instance
http://udn.epicgames.com/Three/Matin...al Param Track


There... That should give you way more information than you probably need.

If you have any issues with them, I'll try to help you out.

[maximsubbota]

Here is my dinamic day cycle http://www.moddb.com/games/stalker-u...cycle#imagebox

[Wyldhunt]

That turned out really nice. Congrats.

[maximsubbota]

Ok, I have the cycle, but how can I make a random rain?

[Wyldhunt]

What are you doing to make the rain? Material, particle, or other?

[maximsubbota]

a particle sistem

[Wyldhunt]

I'm not terribly proficient with Cascade, but I did find the links that look like they'd allow more control via Kismet.

http://udn.epicgames.com/Three/Parti...vent Generator
http://udn.epicgames.com/Three/Distr...tParticleParam
http://udn.epicgames.com/Three/Kisme...Particle Param

Mostly, you need a good system to decide when it should rain so that you can have all of the elements happen together.

In my last project, I had a very simplified and often incorrect version of a weather control that worked great for real time games. Every 4 or 5 minutes, I'd run a script that checked temperature, humidity, water content on the map (Adjusted how quickly humidity rose), and passing high/low pressure areas. That sounds a lot more complex than it was. High pressure tended to maintain humidity while low pressure allowed it to climb higher. Higher temps allowed humidity to climb faster, as well as lots of nearby water. These were all figured with some randomness to keep it interesting. If a high pressure area came through while the temp was dropping, it would release the humidity as rain and the humidity would drop. The higher the humidity, the worse the storm.
That way, I could have the rain and clouds and wind and everything act together to be very dense or not depending upon how bad the storm was.

I think it was about 1000 lines of script, but that included everything for the custom lightning and wind and sounds and everything.

Not sure that sort of thing is the best way for most people in UDK, but that's my experience with weather systems. Perhaps you can take some part of that as inspiration for your systems.

[neurosys]

@Wyldhunt:

I'm currently adding Rain and Lightning to a level. I couldn't get the rain to look right on planes, so now I'm using particles. I had to make a particle system with a wide XY spread (-300 to 300) and -200 Z, still doesnt look wonderful but at least is doesnt look like lines of rain anymore falling uniformly.

ANYWAY my question is this, how do you go about making lightning? and would you perhaps be willing to give ideas on the best way to make a rain texture or have any old examples lying around I've made my own, but its trial and error and I'm not even sure I'm doing it right.

EDIT: Isn't there a way to fill a volume with a particle system so I dont have to copy 50 interspersed systems and let billions of particles fall through the floor of the map?

[neurosys]

Ok, I now have 1 particlesystem for rain and one for the splashing effect on the ground. I have reduced my question down to:

Anyone know how to do lightning? Any ideas on how to start going about it?

Trying to do the actual bolts So I guess I would use a mesh.

[desert_eagle]

for the lighting bolts.its very simple.just draw some in photoshop.and use add shader to overlay them on your sky.then just add scalar parameter to it with 0 value.and then in matinne control it to show the bolts by adding 1 value to the sparam when it rains...its alot simplier if u have day night cycle. =).p.s il recomend to use sine multiply with the lighting bolt tex.with good matched timing

[desert_eagle]

oh and also for the coolnes of the effect.u may add a " wet" mat and make a decal on all the map.and also control it in msatine to show the mat when rains

[neurosys]

we dont have a sky, its a top down arcade style shooter and for this level it will always be raining outdoors. So I guess what I am trying to do is not create the effect of lightning going off in the distant sky, but rather an actual bolt arcing down and striking the ground, emitting the quick flash of light(ambient along the bolt and direct @ impact point), then dissappear and play thunder sounds.

[KenD]

If you have access to or can swing the price of it, Hourences' new vids on Eat 3D show a great way to make all of that. Granted, his tutorial works on a cinematic, but the application of the lightning effects and the lightning bolt could be converted over pretty easy for your game.