Minetest_game: Tuning of node light levels: torches, fire, lava, due to engine light changes

[paramat]

I'm starting work on this, with the intent that torches, fire and lava will be visually slightly brighter than before, but of course with reduced 'light level'.
At the moment i'm thinking in order from lowest to highest brightness:
torch, fire, lava
With all 13 or lower.
To start here's the comparison between 0.4.15 stable and latest 0.4.15 dev:

^ 0.4.15 stable

^ Latest 0.4.15 dev with torch at current level 13

[Desour]

you could make polls on forum and show screenshots to give to the players the decision (but then only mention the votes, dont take them)
but this is a stupid idea, screenshots arent enough to see what light level is good...
but some sort of staged/fake vote could be nice

[paramat]

^ Level 11

[paramat]

Compared to 0.4.15 stable the light doesn't travel as far but is brighter closer to the torch.

Lighting does look less natural now due to it's more linear falloff, but we gain a lot from doing this so i'm not saying it's bad.

[paramat]

^ Fire level 11

^ Lava level 12

^ Meselamp level 14 (unchanged)

[paramat]

I'm thinking lava can be the same level as fire, as it's not an intensely bright lava, it has lots of reds and dark reds.
Perhaps torch 10 or 11, fire and lava 11 or 12.
Obviously need to test torches in caves too.

[Zeno-]

For the reasons discussed in IRC this gets a big no from me. It changes game mechanics in a way that will break many projects in project and is game changing

:-1: :-1: :-1:

Edit: if you're intent on reducing the light levels you have to add another flag (can_grow_things or something) to the definition of a light so that you don't break everyone's worlds (edit 3: except this won't work because the saplings, mods and abms rely on propagated light levels)

Edit 2: Also, which mods and ABMs does this break?

[Zeno-]

To solve the "non-linearity" of the light values (they're supposed to be non-linear, but there should not be such a "jarring" difference between the brighter light levels) I think that a better solution is to apply an "adjustment table" in the engine like was done before, just after gamma correction is performed, when generating the display values for the light lookup table. This solution would not break existing game mechanics.

[Ekdohibs]

This breaks game mechanics many worlds or mods depend on (I am especially thinking about servers with massive underground farms, sometimes even completely automated). So, :-1: from me as well.

[MarkuBu]

I think it is ridiculous to grow with torches. It is to cheap just to put a coal on a stick and have such a benefit

[Wuzzy2]

I agree with Zeno-. The trouble this change may cause clearly outweighs the supposed (!) minor benefits.

[Wayward1]

Again, what about juhdanad's suggestion?

<juhdanad> There could be a 'small torch' for dimmer lighting. And normal torch became more expensive then.
...
<juhdanad> Yes, normal torches can remain untouched if we introduce another variant. And normal torch would cost two coals from now on to compensate the brighter visible light.

Wouldn't this be a viable compromise?

Edit: I do realize this still won't affect growing, this is strictly for the "too bright/dark" discussion.

[Desour]

2 pieces of coal dont burn brighter than one, it only burns longer or have a bigger flame like if you would place two torches next to each other

[paramat]

@Ekdohibs

This breaks game mechanics many worlds or mods depend on (I am especially thinking about servers with massive underground farms, sometimes even completely automated)

Well, torches have never been bright enough to grow stuff, they have always been 13, while all flowers, crops and grass have always needed 13 to grow (requitring a neighbouring light source of 14, a meselamp). Also, a year ago saplings were given a light check (which was missing) so they also need meselamps.
Cactus and papyrus are missing light checks and should have the same requirement of 13.
So this issue is not about growing things.

Instead, do you mean that some mods may rely on torches, fire and lava having their current levels for some other reason? This is a reasonable objection but would the disruption be large?

Sofar's intention for engine lighting changes was to make everything much brighter then reduce torch light level because they are now too bright, as are fire and lava.

For the full discussion and details please read https://github.com/minetest/minetest/pull/4873#issuecomment-266915098 onwards.

[C1ffisme]

Maybe this is going to be a bit of a controversial opinion, but I think this actually makes for good game balance.

• First off, it makes mese lamps have more value, because they light up a huge area and they can grow crops.
• Before you an acquire mese lamps, you will need to grow crops above ground. This also increases the value of minecarts or other forms of transportation.
• In addition, this means that long mining trips require a bit more preparation than just walking into a cave with a pickaxe. Until you get mese lamps, you will have to bring wood with you, so any form of backpacks or movable inventory space also increases in value.

Just my opinion, though. As a compromise, we could add a (possibly rare) "Cave Tree" which grows in low light and only produces small quantities of wood, but that does still break old farms.

[paramat]

@Zeno- I'm sorry i've irritated you, but please read https://github.com/minetest/minetest/pull/4873#issuecomment-266915098 onwards to get your facts right. Most of what you said to hmmmm last night on IRC dev was untrue, you were talking about changes done a year ago and confusing them with recent changes. Hmmmm got the impression torches would be visually darker than 0.4.15,

Please remember this was originally sofar's idea, and part of the plan along with the changes to the light table, but for some reason you're not arguing with him or complaning about him on IRC.

See above:

with the intent that torches, fire and lava will be visually slightly brighter than before, but of course with reduced 'light level'.

[paramat]

Wayward1, no torch should be as bright as the second screenshot, even with 2 coal lumps, we really don't need 2 torch types.

[Wayward1]

Yeah, after more consideration it does look rather bright for a torch..

[paramat]

However, there is an issue about light range, this PR makes torch brighter locally but notice the light doesn't spread as far. So i would be happy for this change to be not so extreme, i would prefer torch to be at least 11, with fire and lava 12.

[rubenwardy]

It's worth noting that this will decrease the range of the torch - I'm not sure I like this

[kwolekr]

Agreed with rubenwardy, this change is something i might agree with if we weren't limited to 16 light levels.

:-1: from me.

[paramat]

Rubenwardy indeed i don't like that either, but notice that a torch is now too bright closer to the torch, so 11 or 12 might be an acceptable balance. Perhaps torch, fire and lava at 12? Which is only 1 level lower than current, the decrease in range is 1 node so barely noticeable, with everything within that range being mush brighter.

This should sit for a while to get input about how much mod breakage there would be. I can't see there being a lot of breakage but i don't know for sure. I feel some breakage would be worth it.
Changing these levels doesn't break anything in MTGame.

Kwolekr, see the 2nd screenshot, do you find this too bright for a torch?

This was partially the intention behind the change to the light curve:
https://github.com/minetest/minetest/pull/4873#issuecomment-266114689
Sofar > "What is important to note, however, is that EVERY LIGHT SOURCE in the game is ~13-14. And that is purely because the game is so damn dark. What needs to happen is that people start making lights with light levels 7-12 and get that atmoshpere back, because right now nobody has any choice at all - a light level of 7 is just not even worth it."
https://github.com/minetest/minetest/pull/4873#issuecomment-266915098
Sofar > "what we want to do is, after 0.4.15, merge this and redo all the light levels in minetest_game - we should lower the torch light level, and possible the mese lamp level too."

[sofar]

I really don't care about existing game mechanics:

1) server admins will tune the light levels to maintain existing builds already
2) old game mechanics are way too easy

It's terrible that everyone is so paranoid about change. Embrace it, change it, try out new things.

right now, in 0.4.14, a torch has an effective light level of ~5 nodes, and then I can't see anything anymore. Even with the light tuned down to 11, the effective range of the torch will drastically improve.

Players adapt much easier than people think. We only hear the most vocal complainants, not the rest of the players that just get on with it.

[Wuzzy2]

Sigh. I think you are right. We should not oppose too much. If I think about it, Minetest Game is actually still FAR from being a decent game/sandbox, so being too crazy about compability will get Minetest Game nowhere.

However, I still don't really see the the benefit of the changed light levels. What's the point? If it weren't for this issue, I would not even have noticed anything. Frankly, it seems I actually don't really understand what this issue is really about. :D

I also don't understand why reducing the light level will make the torch brighter. Shouldn't it be the other way round? o_O Is the light system in Minetest really that messed up?

P.S.: I usually prefer to play with “flat” light because this makes the block boundaries easier visible and I can also easily see how the light gets darker at each step. Would flat light be affected by this proposal?

[tobyplowy]

@sofar

It's terrible that everyone is so paranoid about change. Embrace it, change it, try out new things

+1 I totally agree!

[rubenwardy]

I also don't understand why reducing the light level will make the torch brighter. Shouldn't it be the other way round? o_O Is the light system in Minetest really that messed up?

https://github.com/minetest/minetest/pull/4873

[Zeno-]

@paramat

@Zeno- I'm sorry i've irritated you, but please read minetest/minetest#4873 (comment) onwards to get your facts right. Most of what you said to hmmmm last night on IRC dev was untrue, you were talking about changes done a year ago and confusing them with recent changes. Hmmmm got the impression torches would be visually darker than 0.4.15,

I'm not irritated.

And my facts are 100% correct. As I've said, over and over again, _visual light levels do not matter_. The visual light levels are not what what we're talking about here, though! I think you may be missing the point that there are two representations of light: a) The light value (which ABMs, mods, etc etc rely upon); a b) the _visual_ light value. Changing the visual light value makes no difference at all to the game. Changing the other representation of light values (how they are represented in mods and light spread etc) do change the game mechanics (and this is what you're suggesting doing).

Do not accuse me of not understanding how light works in the game when you obviously have no idea yourself. I never said anything untrue to hmmmm.

Edit: I seem to recall that in the past that nothing in the game had light level 15 which was reserved for sunlight. Edit 2: See also all the old light tables and comments deleted as part of #4873.

[Zeno-]

@sofar if we're so interested in breaking the game, maybe the title and subject of this thread and discussion be changed to also include protocol changes which are needed much more than this hack that could be fixed in the engine anyway without any impact upon existing worlds and games at all.

I mean, since we're talking about breaking existing worlds and mods anyway, we may as well do it all at once, right?

[paramat]

However, I still don't really see the the benefit of the changed light levels. What's the point?
I also don't understand why reducing the light level will make the torch brighter.

This is being done due to the 'light redo' which has made all lights very much brighter, torch is now (2nd screenshot) visually too bright, fire and lava are too. Reducing their 'light level' means we now get a meaningful difference between torches and meselamps/growlamps. Before, all lights were set to near-maximum because the game was generally so dark.
So here when we say 'brighter than before' it means 'visually brighter than before https://github.com/minetest/minetest/pull/4873'.

[paramat]

The visual light levels are not what what we're talking about here,

They are, see my comment above this one.

I think you may be missing the point that there are two representations of light: a) The light value (which ABMs, mods, etc etc rely upon); a b) the visual light value. Changing the visual light value makes no difference at all to the game. Changing the other representation of light values (how they are represented in mods and light spread etc) do change the game mechanics (and this is what you're suggesting doing).

Yes i understand this.

/////////////////////

Sorry for any offense by saying you said untrue things on IRC, i'll explain:

06:29 Zeno I see paramat is still on his campaign to break game mechanics
07:30 hmmmm how so?
07:31 Zeno changing how saplings grow
07:31 (reduced light levels -- actual light levels, not display light levels)

What we're doing now has no effect on saplings, saplings requiring meselamps was done in Oct 2015.
However i admit there may be some minor mod breakage.

07:32 hmmmm well there's nothing necessarily wrong with that
07:32 it's just making it easier to grow underground
07:32 Zeno makes it harder

Meselamp light level is not being reduced, only torch, fire and lava, none of which have ever been bright enough to grow any plant. So what we're doing here has no effect on growing plants.

07:33 Zeno he wants to reduce them
07:33 make torches darker
07:33 hmmmm torches darker!??!
07:33 Zeno yes
07:33 hmmmm you mean they weren't dark enough
07:34 we already need 5000000000000000000000 torches to light up anything indoors
07:34 Zeno i know
07:34 hmmmm i disapprove of that change whichever one it is

I know you meant 'lower light level' but torch, fire and lava will be visually brighter than in 0.4.15 stable. Remember these changes are to be taken together with sofar's light curve change.
hmmmm got the impression torches will be visually darker, but you did not correct him.

07:34 Zeno but by making torches darker all those underground forests that players make impossible (and there are a lot of them)

Saplings requiring meselamps happened in Oct 2015, these recent changes don't affect the ability to grow underground forests.

I tried to explain these points to hmmmm but he stopped talking to me before i could, and ended up thinking all you said was correct. So now you and possibly hmmmm too misunderstand, both your objections are possibly based on misunderstandings.

////////////////////

I mean, since we're talking about breaking existing worlds

No worlds are broken by these changes, as torches, fire and lava were not able to grow plants before either.
There may be a little mod breakage but i think worth it. Which is why we're waiting for more input on how much disruption would be caused by lowering the light levels of torch, fire and lava by 1 or 2 levels. So far there hasn't been any reports of mod breakage, although i expect there will be some.

[paramat]

I'm thinking torch 11, fire and lava 12, i'll make a PR.
As sofar commented the effective light range of these will increase, as will the visual brightness compared to 0.4.15.

[Zeno-]

Based on today's IRC discussion I think there is no more need to debate this because it's become a moot point and seems to have been rejected as in "Won't Add"

Meselamp light level is not being reduced, only torch, fire and lava, none of which have ever been bright enough to grow any plant. So what we're doing here has no effect on growing plants.

Now that is just disinformation. It's not true. They have been able to grow plants since.... since forever

Edit: paramat, do you think that @celeron55 may have intended for torches to be able to grow plants? If not then, surely, he would have written the code in a way that they could not. This "feature" has been a part of the game since I've been playing it :/

[paramat]

Now that is just disinformation. It's not true. They have been able to grow plants since.... since forever

I checked the code, torches have always been level 13 (LIGHT MAX - 1) and all plants have needed level 13 at the plant node, because light attenuates by 1 per node that means a lightsource of level 14 is needed.
You may be remembering mod plants or mod torches.

do you think that @celeron55 may have intended for torches to be able to grow plants? If not then, surely, he would have written the code in a way that they could not.

See above.

[Zeno-]

I am not remembering mod plants or mod torches, and neither is hmmmm. See today's IRC discussion (or yesterday's depending on timezone)

[Zeno-]

<Zeno`> I don't care what happens with display/visual light brightness
<hmmmm> so just to make sure i'm not misunderstanding, you're saying that there is an issue because players don't like the current perceived brightness of the torches due to the light LUT change?
<Zeno`> It's changing nodedefs that concern me
<sofar> hmmmm: I don't think people are complaining about the visual light levels (most people I've seen respond say it's good)
<hmmmm> yes, and i agree
<Zeno`> well, why change nodedefs then?
<hmmmm> so could someone tell me what the *issue* is?
<hmmmm> nobody needs to change anything
<Zeno`> the issue is that paramat wants to change them
<hmmmm> and there is a massive opposition to his proposed change
<hmmmm> it's called a pull REQUEST for a reason
<Zeno`> good :) So no issue then
<hmmmm> request denied

[paramat]

Hmmmm is not a game dev.
Remember this was originally sofar's idea, so don't say it is only me suggesting this.

[paramat]

Ok i just saw that sofar no longer wants to reduce these light levels, so this PR probably won't go ahead, i'm not too bothered, it was the misunderstandings that bothered me.
We won't make torches bright enough to grow stuff though, it's never been that way and is too easy and ridiculous.
@sofar can you confirm you no longer want to change these levels? Then i'll close this.

[paramat]

VanessaE hmmmm: to be perfectly honest, what's the delay on that? this isn't something one should need to "work on"...

VanessaE so he's had time, if he intends to make one

VanessaE: I'm working on making new non-cubic mese lights to be used for growing things, give me time, there's no rush.
Those ilights are ugly and far too HD, do not submit those.
Good textures take a long time to make, have patience.

[paramat]

01:47 VanessaE I guess it's because a year ago, more light became required to grow crops than what a torch could produce

VanessaE because it would seem that we need to roll back to light relationships that were in place a year ago

Nope, read the above, torches have never been bright enough to grow any plant, saplings used to grow in darkness only because they were missing a lighting check. We cannot now make torches bright enough to grow plants. Just wait for the new prettier mese torches i will make.

VanessaE apparently they need too much light to grow
02:05 making underground farming impossible

Not impossible.

[paramat]

sofar I think we just need to come up with some compromise
01:50 e.g. require 12 to grow crops, and 13 for saplings
01:50 make torches 13, mese lamps 14

Nope. Torches have never, throughout Minetest history, been bright enough to grow anything (i checked the code), quite rightly, it's too easy and ridiculous.

[Desour]

this change wont be a big problem for players, they are adjusting, theres no need to be that conservative

also i got a question:
will all placed light sources automatically get the new light level or will only the newly placed ones?

[Zeno-]

@paramat you keep saying it's ridiculous. But who says it's ridiculous except for you? The people who play the game apparently like it, otherwise why would they build all this stuff?

Edit: I think YOUR idea is ridiculous. So we're even I guess.

Edit: You're the one who is always bringing up the issue of not changing the "spirit of minetest" or something like that. And yet this suggestion and https://github.com/minetest/minetest_game/commit/ef8b7e230d17b424749e0ce428720afa7ac4fe6d significantly chang(ed) the spirit of minetest and gameplay and remove(d) some things that many players liked and relied upon. So I'm not sure what's going on

[paramat]

Well, the links i gave you show 3 people supported the issue and PilzAdam supported the PR, it then had a surprisingly small amount of objections. It's consistent with other plants which have light checks.

When saplings had no light checks players would, of course, take advantage of that, but i expect most players would admit they had it too easy and it is reasonable to make saplings consistent.

That PR a year ago just meant that players would use meselamps instead, so it did not make anything impossible or remove something relied upon. However i admit that i have just seen that meselamps require 3 mese crystals and i consider that far too expensive, so growing saplings did indeed become too expensive, someone should have complained about the recipe and we would have happily changed it.

I'm now actively making growing stuff underground easier through a recipe change, and less ugly by adding new lights, so i am addressing the complaints.

DS, this suggestion very probably will not go ahead.
So, i'm closing this.

[Fixer-007]

Why not adapt growth requirements for new changed torches? (say level 11, as example), or maybe If we have more cheap mese... we can leave it as it is? Just a quick though.

[paramat]

Light levels for torches are not changing now.

[Zeno-]

The light level for can_grow (13) appears to have been selected randomly without consultation anyway. So, shrug, it should just change

[ssieb]

It makes sense to me, the light level to grow plants should be fairly close to sunlight level. If you're wanting to grow plants underground you're going to need a grow light, not just a few torches.

[Zeno-]

ssieb, plants do not need a lot of light to actually grow (citation: me -- I'm a botanist IRL)

[paramat]

Well 13 is the lowest level that requires more than a torch so it may have been chosen deliberately.

Zeno, plants generally need the right type of light (daylight) surely? The light spectrum of a torch or fire is not suitable?

[rubenwardy]

Unreliable, but askscience says it's unsuitable https://www.reddit.com/r/askscience/comments/10i7nk/can_fire_be_used_as_a_light_source_in_order_to/?st=ixg8z8rn&sh=2cf17f79

I don't particularly care enough to find and read an actual paper.

But it's worth noting that we should place gameplay above realism

[Zeno-]

@rubenwardy your link actually suggests that it is suitable

[paramat]

I guess it may be theoretically suitable, but any fire bright enough would produce so much heat that it would destroy the plant.
Anyway, although MTGame is only loosely realistic i don't think a crude and cheap torch can be considered suitable to grow a plant, or even able to grow a plant slowly.