Support / stability of mapgens

[paramat]

* Any added mapgen, and worlds using it, will always be supported.
* We always try to minimise any changes after a mapgen is added, or make them options if possible.
* The chance of user-unavoidable changes to a mapgen, and the size of those changes, reduces over time.
* Usually the worst change that can happen is terrain being discontinuous between existing world and newly-generated world. This has happened in Mapgen V7 at least 2 times, but years ago, it is fairly settled now. Even in this case, mods exist that can smooth-out the abrupt changes that run along mapchunk edges.
* Any mapgen that is in an experimental, highly changeable state will be described as such in documentation (in the 'mg_name' section of minetest.conf.example). Currently: The optional floatlands of v7 (disabled by default).

[Wuzzy]

Thank you, this is interesting information, but how is this news? ;-)

Information like this needs to be written down in README files, documentation, etc. instead of scattering it in the forums.

[paramat]

Updated to clarify that only 3 mapgens are officially stable.

[v-rob]

I find it funny how mgv5 was made in 2011 and it isn't considered stable. :)

Singlenode is stable?! *Gasp!* :P

[rubenwardy]

I find it funny how mgv5 was made in 2011 and it isn't considered stable. :)

Singlenode is stable?! *Gasp!* :P

The v5 we have now was made much later, around 2015 or 16 I forget. The original v5 was removed.

[v-rob]

Yes, but it still uses the same noises (with a few modifications, I believe)

[twoelk]

Yes, but it still uses the same noises (with a few modifications, I believe)

rather, total rewrite to achieve the same effect

[Wuzzy]

What exactly are the differences between the historical mapgen v5 from 0.3 and the current mapgen v5?

So far the only obvious difference I know of is usage of the biome API.
I believe the terrain shape is mostly the same. But is it identical?

[paramat]

For mgv5:
Terrain surface shape is identical or as close as it can be. The eased 3D noise new mgv5 uses may create a slightly different shape to the original 3D noise implementation.
The 3D noise tunnels are identical in shape.
Old mgv5 only had these tunnels and had random water and lava sources added underground. New mgv5 doesn't have these sources, instead it adds the 'large caves' from mgv6, which often contain water or lava, these were considered a better way to include underground liquids.
Also there is an option (default enabled) for the giant caverns deep underground.

Of course, the biomes, ores and decorations are completely different.

[Brian Gaucher]

My question is.

When will mgv7, mgflat, and mgvalleys become stable?

Mgfractal will probably never be, given it isn't meant to be used in servers or for actually playing (mostly testing, proof-of-concept). And mgcarpathian is quite new.

Also, I think Minetest could have a tab that describes each MapGen. I still have no idea what they each are (other than fractal, flat and singlenode).

[paramat]

Mgv7 surface and underground is stable. The floatlands are not but they are disabled by default, they also seem quite well tuned so they might become stable at 5.0.0.

Mgflat in flat mode is stable. The only uncertainty about stability is the 'lakes' and 'hills' options but there seems no reason to alter those.

Mgvalleys and mgv5 seem near-stable. maybe for 5.0.0.

We're very hesitant about officially announcing a mapgen as stable because that is a big commitment that rules out certain types of improvement. However mapgens are often near-stable long before being 'officially' stable.
If you wait for official stability you'll miss out on good stuff for years. It's better to accept that very occasionally there may be a discontinuity in terrain.

[hajo]

Mgv7 surface and underground is stable. The floatlands are not
Mgflat in flat mode is stable. The only uncertainty about stability is the 'lakes' and 'hills' options

mapgens are often near-stable long before being 'officially' stable.
very occasionally there may be a discontinuity in terrain.

Would it be possible to detect such discontinuities ?

Eg. with a mod that gets called whenever new terrain is generated (and writes a logfile),
and another mod that keeps emerging more and more of the map.

[paramat]

A mod might be able to detect large flat walls running along mapchunk borders yes, and that mod could possibly also smooth the transitions.

[Krock]

and that mod could possibly also smooth the transitions.

Yes, such a mod already exists. However, detecting borders is slightly more complicated. It would need a on_generated callback which then loads the surrounding mapblocks to check whether there's a large change in terrain height in order to flatten it there. In addition to the height change, the biome might also have changed - which has then to be spread a bit to make the transition look acceptable.
It's much work to implement this - and the mod would cause additional lag for each new chunk to ensure a continuous terrain.

[ExeterDad]

Yes, such a mod already exists.

Whoa! How did I not know of this tool? Impressive videos!

[Bing Bot [Bot]]

Yes, such a mod already exists.

[paramat]

I intend to have mgv5 and mgflat announced as officially stable for 5.0.0.
Mgvalleys is still somewhat of a mess, that i am slowly sorting out, so won't be for a while.
Mgcarpathian i might add a feature to (that has support from the mapgen creator), and is quite new, so again not for a while.

[paramat]

For Minetest 5.0.0 Mapgen V5 has been made 'officially stable'.
However Mapgen Flat has not.
The new list of officially stable mapgens is: V5, V6, V7, Singlenode.

[paramat]

Due to discussion on IRC http://irc.minetest.net/minetest/2019-03-19#i_5515386 and http://irc.minetest.net/minetest/2019-03-19#i_5515584 i realised that this 'officially stable mapgen' commitment and terminology gives the wrong impression, worries users unnecessarily and is quite inaccurate.

It gives the impression that any 'non officially stable' mapgen is likely to go through extreme changes or maybe even become unsupported in future, this is not the case.
It also gives the impression that 'officially stable mapgens' never change. In fact, even Mapgen V6 has occasionally changed slightly by necessity.
It gives the impression of 2 fixed states and a clear divide between them, this is not the case.
It had the effect of core devs wanting to delay as long as possible announcing a mapgen as 'officially stable', because the thought of not being able to change anything is quite scary. And then, the long delay was unnecessarily putting users off using the newer mapgens for many years.

So i'm now going to trash this classification and describe how things actually are, which is:

* Any added mapgen, and worlds using it, will always be supported.
* We always try to minimise any changes after a mapgen is added, or make them options if possible.
* The chance of user-unavoidable changes to a mapgen, and the size of those changes, reduces over time.
* Usually the worst change that can happen is terrain being discontinuous between existing world and newly-generated world. This has happened in Mapgen V7 at least 2 times, but years ago, it is fairly settled now. Even in this case, mods exist that can smooth-out the abrupt changes that run along mapchunk edges.
* Any mapgen that is in an experimental, highly changeable state will be described as such in documentation (in the 'mg_name' section of minetest.conf.example). Currently: The optional floatlands of v7 (disabled by default).

I hope users can now be more relaxed about using the newer mapgens.

[Wuzzy]

* Any added mapgen, and worlds using it, will always be supported.

Like math and indev? :P

So i'm now going to trash this classification and describe how things actually are, which is:

Why is this thread still open then?

[paramat]

Correction to the above:

Code: Select all

#    Current mapgens in a highly unstable state:
#    -    The optional floatlands of v7 (disabled by default).

[v-rob]

Everyone should just use singlenode. That will never break :)

[Linuxdirk]

For Minetest 5.0.0 Mapgen V5 has been made 'officially stable'.
However Mapgen Flat has not.

Which is absolutely fine since "flat" usually spawns you in a massive forest instead of on a flat surface.

And no, mods or custom mapgens are not an option. "flat" means ... well ... flat. Not forests.