New weather system proposition

[MirceaKitsune]

I have been thinking of adding a new weather system to Minetest, based on a new approach (no finite liquid). My idea is a Lua function which sets a group of client-side visual effects per player. This would allow a lag free and more complete way of triggering weather effects, whereas all attempts to code weather in Lua failed.

Below is an explanation of the Lua function I intend to add, and a description of what effects I'd like the weather system to contain. I'd like users to let me know what they think of each feature, and developers to do the same and also specify if and how the idea is acceptable. I don't wish to work for nothing and create code that won't make it in Minetest, so please voice your opinion. I also added a pool so I can easily see how popular the idea is.

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Code: Select all

# random usage example
player.set_weather({
    sky_color = {r = 64, g = 96, b = 128},
    particle_speed = 0.1,
    particle_texture = "raindrops.png",
    particle_sound = "raining.ogg",
    humidity = 0.5,
    wind_strength = 0.25,
    wind_direction = 90,
    wind_sound = "woosh.ogg",
}, 10)

- sky_color: This color replaces the color of the sky and fog, based on the value of the "humidity" parameter. When "humidity" is 0, the sky is the default color... when 0.5, the sky is halfway between the default color and this... when 1, the sky uses this color.

NOTE: I'm aware that there's already is a set_sky function. The reason I'm proposing an additional sky coloring parameter here is for weather effects to not interfere with the original sky settings. set_sky was intended as a permanent effect which defines the environment, and not to be used dynamically for weather... while it would also not respect the "humidity" parameter used for gradual appliance / transition. The sky modification here will be applied on top of set_sky and the colors chosen in it... so if you used set_sky to make the sky pink, blue weather sky will transition through purple.

- particle_speed: How fast particles fall. A large value should be used for rain and a small one for snow. Particle count itself depends on the "humidity" parameter; When humidity is 0, there are no weather particles... and when 1, the maximum amount of particles is used. I intend to code a special client-side particle spawner, which circles around each player while preventing particles from reaching indoor areas too.

- particle_texture: The texture used by precipitation. Rain drops, snow flakes, etc.

- particle_sound: The sound played by particle spawners or particles as they fall.

NOTE: I'm aware that a weather mod could separately use minetest.play_sound here. But I'd prefer to add a separate precipitation sound, so each active particle spawner can play it... making sure you hear rain coming from outdoor if you're sitting in a house for instance. Doing the sound manually would be difficult and laggy.

- humidity: The parameter which decides the intensity of all weather effects described above: Sky color replacement by the "sky_color" parameter, and particle density for the "particle_*" parameters. However, this also aims to modify other visual effects not defined within set_weather explicitly, such as:

* Clouds density: 0 means no clouds, 0.5 makes the cloud pattern halfway full, 1 fills the cloud pattern. I'm not sure how to modify the builtin clouds to work this way, and might need some help here.

* Fog strength: 0 means fog distance represents draw distance, 1 brings fog as close as possible. Simulates humidity making everything foggy.

- wind_strength: A special feature I wish to add is wind. Currently I plan to give wind the following effects:

* Clouds: They should move in the direction of "wind_direction" at the speed specified by "wind_strength".

* Precipitation: Rain / snow particle direction shall be influenced by wind the same way.

* Waving: When shaders and wavering leafs / liquids are enabled, "wind_direction" and "wind_speed" should change the effect. When there's no wind, liquids and leaves should not deform at all. When wind is at maximum intensity, fluids and leafs should swing very quickly and violently. RBA (RealBadAngel) might need to look into this one.

* Wind audio: An ambient sound should be heard when there is wind... representing the sound you hear in real life when wind blows into your ears or a microphone. "wind_strength" should obviously determine the volume... but if possible, "wind_direction" should also influence the stereo balance so you hear the wind from where it's blowing.

- wind_direction: Direction wind blows from in degrees (0 to 360), explained above.

- wind_sound: The ambient wind sound, described above.

- 2nd parameter (located outside the brackets): This value represents the transition rate. If 100, it takes 100 seconds for sky color / particle density / wind / etc. to transition from one value to the other. This will allow the server to send a weather package only once, and have the weather get good / bad gradually.

[Inocudom]

Your ideas would gain more favor in Freeminer, a fork of Minetest managed by xyz and proller. It really needs someone like you. Look below:
http://freeminer.org/

[Xanthin]

This looks like a great idea to have more immersive effects in the game. Imagine exploring a humid area with suddenly dark sky and rain making the view bad, while in a desert region all you have is this howling wind (and maybe sand particles?).
Unfortunately I can only basicaly speak from a players point of view. I try to understand how the weather is localized with the humidity value: depending on node types, like low value on desert sand, high value on sand/water? Or is it like a global random effect? And while I can imagine that the particles only appear where the player is, will the syk colour also only change in this "active" range (are there transitions possible at the border to other areas, so you dont have a square area of dark sky surrounded by normal sky?) or is it a global effect (like dark sky until the horizon)?

[VanessaE]

Some notes (mostly as stated on IRC, with addenda):

Suggestion: Allow the server to tell the client to follow the local humidity as defined by the perlin layer that creates desert areas on the map (same idea plants_lib uses to read humidity). If necessary, allow the modder to explicitly provide a new perlin map for this. That way the humidity can increase and decrease as the user approaches a desert. if it's raining at the edge, the rain gets worse as the user walks further into the grass, etc.

Similarly, it would be useful if precipitation could be made to vary with elevation. Just some density multiplier, nothing fancy.

That way it keeps the no-lag idea of the feature.

Furthermore, I think there should be separate settings for the shift in sky color and precipitation density, relative to the apparent humidity. A simple multiplier for each, or something. In the real world, for example, there's usually not that much fog when it's snowing, compared to when it's raining, yet the sky is often quite grey and overcast.

[stu]

I am all for adding api features to facilitate server-friendly weather systems, although the weather itself should still ideally be implemented in a Lua mod (imo).
If I read this correctly, that is pretty much what you are suggesting here, right?

+1 from me anyway :)

[Minetestforfun]

Good idea, we need a good weather system like you say !

[Krock]

I like your idea but I would prefer bugfixes instead of starting this big project.

[Sol]

I like your idea but I would prefer bugfixes instead of starting this big project.

B-b-but I want both. ):

[MirceaKitsune]

Regarding the use mapgen perlin hummidity: My function is intended to be used like that actually, although the mod must obtain perlin parameters manually. A simple weather mod would scan the position of each player every 10 or so seconds, the mapgen temperature / humidity in that area, then run player.set_weather accordingly. Automating humidity based on perlin noise in the C++ code is not an option... both because I don't know how, and because the old weather system (that got removed with finite liquid) did this but was no longer wanted.

Regarding fixing bugs, I don't see how this and other new features get in the way. As for Freeminer, I heard of it and it's an okay idea to have a fork more open to new features. But personally I'm most interested in mainstream Minetest currently. Freeminer can of course integrate my code earlier than mainstream MT, and it's encouraging to know it might land at least in there.

[ExeterDad]

If I understand correctly...
The server tells the client when and where weather is occurring. Then the client machine produces it if the users opts in and the user machine can handle the extra load? If so, I'm all for it.
I like very much the possibility of wind. And if the existing trees and plants respond to that wind even better! I have plant movement off when I play as the uniform rhythmic swaying drives me bonkers. Makes me feel as if I'm playing in a fish tank. But in world items responding to random actual wind would be cool.
Not to mention the mods that could gain from this. Windmills. Sailboats, flags, laundry hanging on a line, or whatever.

[twoelk]

Oh I'd love to go over the top with this ...

Wind would be lovely for a sailing simulation. With changing wind directions this would make travelling and exploring in some survival-adventure game more interesting. Just imagine having to take the current wind direction into account when boarding your sailing ship or ballon. Not that we are there yet but it would be great if the fundaments for such things were present.

Similarly wind directions could affect some future weather phenomena such as snow drift, movement of thunder storms or sand storms.

I wonder if weather should be part of some sort of atmosphere api. This might open some more general ways to influence not only weather but also the absence of it such as games with a space theme. This api could then be used to direct what happens if you add an artificial environment such as colonizing some space realm would include. It could then of course be used to generate any, including not earth like, weather.

Thinking of the corner case " gravitation-less space game without ground surface", as mentioned by c55 here, I think the falling velocity should rather be done by some generall gravity code that calculates the falling speed and drift according to some parameters given by the object/entity. Just to keep the door open and path the way to some generic physics engine that is not hardcoded on the values known from our planet but allow for different, non earth as we know it, scenarios.

Mind this does not need to aim at yet another simple space shooter but could also foster some magical fantasy world with a weather system and physics that follow altogether different rules as those that our teachers taught us at school.

[MirceaKitsune]

To answer the above question, the idea is to add a Lua function which allows the server to tell players what the weather is like. Upon receiving the packet, the client simply applies a set of visual effects accordingly. Same idea minetest.set_sky uses for example, only that I intend it for more complex weather effects.

Anyway, there seems to be overwhelming support in favor of this idea, so I shall certainly look into it eventually. I am however still waiting on admins to tell me what I to be careful about, and under what conditions this would be accepted.

One thing I should warn about: This might change functionality of certain existing effects. For example, I plan to make the 3D cloud movement direction depend on wind... so if minetest_game and other existing games don't set any wind, the clouds will be static... which means changing default behavior. In fact, if there's no humidity, they should be removed entirely... meaning no 3D clouds at all until set_weather is used. Anything else would seem illogical, so I wonder how acceptable this is.

[VanessaE]

Keep the clouds running. It's not like having clouds in the sky in the real world always means there's some kind of precipitation due. Besides, the sky will look too boring then.

[MirceaKitsune]

Keep the clouds running. It's not like having clouds in the sky in the real world always means there's some kind of precipitation due. Besides, the sky will look too boring then.

True... but at the same time, cloud density and speed should match weather. It's hard to fully decide how to go here... so the function can take as little parameters as possible, while the client-side effects work in harmony together, and don't affect current defaults too much.

One idea would be: Only start having precipitation when humidity >= 0.5. That way, 0.25 could work to have clouds be as dense as the current default ones, but 0 should be used to remove them entirely... the default value could then be 0.25 and everyone is happy. Fog could start getting denser than draw distance when humidity >= 0.75, to further ensure that everything works gradually.

[philipbenr]

I think that this idea is really good and that your above suggestion is a good one.

And I really don't know how magpens work, but if mgv7 has easily buildable biomes, then you could put a function that triggers a change in the weather in the biome.

Still, that brings up a problem. What happens if the player is at the border of a desert and he is on the brink of entering a jungle (rainforest)? There would have to be certain biome changes that allow for space between borders. Like using biome blend. You would figure out what position in relation to a biome you were, like if you were near a rain forest, things would start clouding up, and things would get more and more foggy. If you got near to a desert, things would clear up, and few clouds would be in the sky.

Sorry for clogging up creativity, but this is always something that has bothered me.

[MirceaKitsune]

The solution to biome transitions would be easy: The Lua function which checks player positions can run every 5 seconds or so. If the player is detected to be in a different biome, we call the function again to update fog color and weather particles (humidity can stay unchanged, by leaving the value nill).

On the downside, this does mean that for the first 5 seconds after walking into a new biome, you see weather from the previous biome. I should indeed think of a better way to do this, although I can't promise one may be found. We don't have a system like Minecraft after all, where air nodes appear to be drawn like a plantlike drawtype with a rain texture when it's raining.

[philipbenr]

Ok, thanks for clearing that up.
A solution to that problem would be to find a way to check the places around the character. Have the function check what nodes are around the player, like checking the tpyes of nodes in a sort of octagon around the player. Have each one of the vertices check the material type, and determine what sort of effect should be placed in the character's area. That way, we could tell what sort of area the player is in. Transition to a forest biome, no problem. There would be some lag in the biome change, but not so bad.

I am no serious lua guy, so I of course do not know if this is possible.

[MirceaKitsune]

Ok, thanks for clearing that up.
A solution to that problem would be to find a way to check the places around the character. Have the function check what nodes are around the player, like checking the tpyes of nodes in a sort of octagon around the player. Have each one of the vertices check the material type, and determine what sort of effect should be placed in the character's area. That way, we could tell what sort of area the player is in. Transition to a forest biome, no problem. There would be some lag in the biome change, but not so bad.

I am no serious lua guy, so I of course do not know if this is possible.

I thought about that, and it would be a much nicer idea. We could make each particle spawner circling the player create differently textured particles based on where that spawner is located. So when you sit in a desert biome but near a snow biome, you see a sand storm behind you but snow falling in front of you, past the line between the two biomes.

Unfortunately however, I don't see a way to do this, due to two challenges. First one is detecting the biome's perlin heat / humidity in the code, and further more doing so client-side! The hardcoded function to do that was removed with finite liquid months ago, and mod creators are struggling to even find a way in Lua that does that. A much more experienced developer would need to re-implement this upstream, as well as make the client aware of it. I'm all in favor of this, if a dev willing to do it is found.

Second issue is how to define weather in the Lua function. Since in this case, weather particles (texture, falling speed and mass, etc) need to be defined in a list, and each one to start / end between a certain humidity / temp range. This wouldn't be a big problem though, and I could find the cleanest way to do it.

[rubberduck]

i like the idea with weather implemented in the game.

in my opinion temperature should be influenced by height too.
When the map is generated, the map generator should automatically generate snow in cold areas. On VanessaEs Survivial server, where snowdrift is installed, it doesn't generate snow when you come in a new area of the map.

[VanessaE]

Regarding temperature and humidity, get the perlin settings used by Snow Biomes mod and the regular desert generator, respectively, and just use those. Let's not over-complicate this like what happened with that broken "weather" code from last time.

Changes have to be checked-for in realtime on the client for one reason above all else: the player can move 20 meters per second when running, if this hasn't been changed somewhere (i.e. in the game they're playing). That means you could cross several biomes in the proposed 5 second check interval.

It's okay if the server hasn't told the client about the weather in a given area (so the client treats it as clear weather), but it's honestly not okay if it keeps raining over the player when they're deep in a desert 100 meters away from where the rain started, even if it's just due to the proposed checking interval. Nevermind how much server lag will be added to that in practice.

[philipbenr]

@ VanessaE: This last bit is true. Server lag would be increased, and as MK said above, it should be a group of client-side visual effects for each player. I also agree that it should be real-time checking, and not every 5 seconds.

+ "Offtopic"

What's with the sprinting? That is really not humanly possible. Halving the running speed would be better. There are reasons why to keep it as so, but I am just saying it is not realistic and kinda takes away from gameplay.

[SAMIAMNOT]

I thought there already was a weather mod. Whats wrong with that?
*EDIT* I voted that some things should be changed.
1) Snow should pile up by default
2) It should always snow on Christmas, all Christmas, with a huge gray cloud over every part of the sky.
3) You sloud leave the normal clouds alone. If you make your own clouds you can give them a shadow which lets the player know something is brewing. Your clouds should be a little darker gray than the normal clouds.
4) There should be thunderstorms with thunderclouds. The clouds should be a really dark gray and when youre under it its as dark as night. Lightning should strike tall and high objects, burning them. Trees should fall down if struck. And lightning should last after the storm. That way a fire could be started by a lightning bolt striking a tree or something. And you should try to make support for as many third party plants and mobs as possible. So like the Jungle trees from Vanessas plantlife mod (good job BTW) will be vurned too, and so will bushes.
5)Lightning will kill you on contact.

[MirceaKitsune]

I thought there already was a weather mod. Whats wrong with that?

Weather mods written manually in Lua are very inefficient and / or laggy. The effects need to be hard-coded client-side.

[SAMIAMNOT]

Is this actually going to be programmed?
I have tons of ideas and Im going to learn Lua sometime so maybe I can implement them. ;) But til then:
Idea #6:Lightning sounds you can hear for "miles." (hundreds of blocks.)
Idea #7: Weather Forecaster device, a little device that if placed on the ground, will show on the HUD the current weather on the block and a forecast for the next ten minutes.

Would this be a mod?

[fraang]

+1

Sounds cool and brings live to the minetest worlds. :-)

[stormchaser3000]

my idea would be that most of this could be client side. all that would be needed would be for the server to send out when it's raining and when it's snowing (would probably lag a lot less).

[stormchaser3000]

my idea would be that most of this could be client side. all that would be needed would be for the server to send out when it's raining and when it's snowing (would probably lag a lot less).

EDIT: also when it's not raining or snowing.

EDIT: oops i meant to edit the last post.

[SAMIAMNOT]

Is this actually going to be made? I cant wait for it, now you have me all excited.

[MirceaKitsune]

Is this actually going to be made? I cant wait for it, now you have me all excited.

Depends. Currently I'm waiting for more feedback from other developers. Then I have to start wondering how to actually code all this... won't be an easy challenge.

I'm considering splitting this into multiple features to be honest. set_sky could remain the best option for changing sky settings... although it eventually needs to support fading, as well as some sort of brightness correction based on daytime. Weather particles should then be their own function, and simply coded as a special particle system. Wind could also be coded as a different function and at a later stage.

[TriBlade9]

Perhaps something similar to add_particle?
IMO a weather system would be a bit too generic. What if you wanted a floating HUD that was displayed in front of a player, or a visualization of an effect or an arrow to show which direction to go.

Perhaps rename it to add_particle_system, with the option to lock it to a player. Give it options for radius around player, move with player or not, etc.