Difference between revisions of "Map Generator Evolution"
(→indev: Smaller imgs) |
(mention Luanti name) |
||
| (76 intermediate revisions by 5 users not shown) | |||
| Line 1: | Line 1: | ||
| − | === | + | {{Languages}} |
| − | [[File: | + | This article shows the development history of the [[Map generator|map generators]] in Luanti. |
| − | + | ||
| + | == Development of a single map generator == | ||
| + | Initially, Luanti (then called “Minetest-c55”, later “Minetest”) had only one map generator which was continously improved and had its own version number, where each version replaced the previous one. The earliest map generators are based on 2D Perlin noise. | ||
| + | |||
| + | === Early development === | ||
| + | Also dubbed “Version 0”, this section summarizes the earliest map generator experiments before the release of the first official map generator. | ||
| + | ==== minetest-c55-101010000530 ==== | ||
| + | [[File:First_mapgen.png|thumb|650px|The first mapgen]] | ||
| + | In the very first known version of Minetest-c55, there was just flat terrain made out of grass blocks with [[stone]] pyramids on top. There were a few holes. There were no other blocks or caves. The terrain was always the same. | ||
| + | {{-}} | ||
| + | |||
| + | ==== minetest-c55-101017205222 ==== | ||
| + | [[File:Earliest_terrain.png|thumb|650px|Undefinable terrain]] | ||
| + | <!-- [[File:putkiksia.png|thumb|650px|Some players messing around]] NOTE: This screenshot is hidden because it seems to show a player structure --> | ||
| + | The terrain was no longer flat and the pyramids are gone. The terrain generation was horrible, but at least terrain could be generated. It consisted of grass blocks and stone at surface. Very simple squareish caves could be found below the surface. The terrain was still not random. | ||
{{-}} | {{-}} | ||
| − | === | + | |
| + | ==== minetest-c55-101024231736 ==== | ||
| + | [[File:First_water_mapgen.png|thumb|650px|First water generation]] | ||
| + | [[Water]] has been added and forms oceans at a fixed sea level. | ||
| + | {{-}} | ||
| + | |||
| + | ==== minetest-c55-101101170627 (and later) ==== | ||
[[File:Puita jee.png|thumb|650px|The first trees]] | [[File:Puita jee.png|thumb|650px|The first trees]] | ||
| − | [[File:Grumbuduts ymparisto.png|thumb|650px| | + | [[File:mapgen updated.png|thumb|650px|More trees]] |
| − | + | [[File:Grumbuduts ymparisto.png|thumb|650px|Even more trees]] | |
| + | [[Tree]]s with [[leaves]] were added in, but they were very basic. Bushes (a single leaves block on the ground) were added as well. These primitive bushes have been removed in a later version. | ||
{{-}} | {{-}} | ||
| + | |||
=== Version 1 === | === Version 1 === | ||
| − | [[ | + | <!-- TODO: Replace this low-quality screenshot! --> |
| − | + | [[Image:Mapgen v1.png|650px|thumb|Not mapgen version 1, but very close to it.]] | |
| + | The first official mapgen was introduced in Minetest-c55 0.0.1. Features: | ||
| + | |||
| + | * Simple, '''random''' terrain with [[stone]] and [[Dirt with Grass|dirt with grass]] | ||
| + | * [[Dirt]] generates below water and at some beaches | ||
| + | * Trees (consisting of [[Tree]] and [[Leaves]]) | ||
| + | * Simple lakes and oceans at a fixed sea level | ||
| + | * Simple caves and ravines (vertical caves) | ||
| + | * First [[ores]]: [[Mese Block|Mese blocks]] and [[Coal Ore|coal ores]] are generated underground | ||
| + | |||
{{-}} | {{-}} | ||
| + | |||
=== Version 2 dev3 === | === Version 2 dev3 === | ||
[[File:Mapgenv2 3.jpeg|thumb|650px|Mapgen 2 dev3]] | [[File:Mapgenv2 3.jpeg|thumb|650px|Mapgen 2 dev3]] | ||
| − | Mountains were made more pronounced | + | Mountains were made more pronounced, ore generation was better and trees have been improved. Although this was a development version. |
{{-}} | {{-}} | ||
=== Version 2 dev4 === | === Version 2 dev4 === | ||
| Line 21: | Line 53: | ||
{{-}} | {{-}} | ||
=== Version 2 === | === Version 2 === | ||
| − | [[File:Scenery2.jpeg|thumb|650px|Mapgen 2 | + | [[File:Scenery2.jpeg|thumb|650px|Mapgen 2]] |
| − | + | [[Sand]] has been added and formed sand beaches. A simple mud flow algorithm smoothens out dirt / dirt with grass hills. The cave generation has seen notable improvements and [[Iron Ore|iron ore]] has been added as well. | |
{{-}} | {{-}} | ||
| + | |||
=== Version 3 "3d noise" === | === Version 3 "3d noise" === | ||
[[File:Turbulence cliff test.jpeg|thumb|650px|A giant cliff]] | [[File:Turbulence cliff test.jpeg|thumb|650px|A giant cliff]] | ||
| − | 3D noise is used to generate this terrain. | + | 3D Perlin noise is used to generate this terrain. |
{{-}} | {{-}} | ||
| Line 33: | Line 66: | ||
More tweaking. | More tweaking. | ||
{{-}} | {{-}} | ||
| − | === Version 5 | + | === Version 5 === |
| − | [[File:Minetest mapgen5 funky.jpeg|thumb|650px|Historic mapgen | + | [[File:Minetest mapgen5 funky.jpeg|thumb|650px|Historic mapgen version 5 in Minetest-c55 0.3.0]] |
| − | Official map generation for version 0.3.1. It is iconic for its extreme and often “blobby” terrain | + | Official map generation for version 0.3.1. It still uses 3D Perlin noise like the previous versions and is iconic for its extreme and often “blobby” terrain. In the 0.3 versions, this map generator hat predefined biomes like the current v6 map generator. In Minetest-c55 0.4, it was removed, but has been revived later (→[[#v5]]). |
This version of the map generator is also used in [[Overview_of_Minetest_forks#Voxelands|Voxelands]], a fork of Minetest-c55. | This version of the map generator is also used in [[Overview_of_Minetest_forks#Voxelands|Voxelands]], a fork of Minetest-c55. | ||
| Line 41: | Line 74: | ||
=== Version 6 === | === Version 6 === | ||
| − | [[File:Screenshot 2438759180 mapgenv6.jpeg|thumb|650px|Mapgen | + | [[File:Screenshot 2438759180 mapgenv6.jpeg|thumb|650px|Mapgen version 6 in an early version of Minetest-c55 0.4]] |
| − | [[File: | + | [[File:Plains.png|thumb|650px|Plains biome in mapgen version 6 (before Minetest-c55 0.4.3) with visible “terrain lines” which were fixed later]] |
| − | Version 6 | + | [[File:Mountain.png|thumb|650px|Mountains in mapgen version 6, before Minetest 0.4.7]] |
| + | Version 6 of the map generator was introduced in Minetest-c55 0.4.0 to replace the map generator version 5. This version uses 2D Perlin noise again and the terrain is now much smoother and more realistic than of the previous version. Map generation has also become much faster. | ||
| − | This | + | This version introduces jungles, deserts and rare gravel fields. |
| − | + | Version 6 was the last version of the only map generator before support for multiple map generators has been added. This mapgen has then directly be continued under the name “[[#v6|v6]]”. | |
{{-}} | {{-}} | ||
| − | == | + | == Development of multiple map generators == |
| − | Since | + | Since Minetest 0.4.6, players are able to choose one of multiple map generators, with v6 being the default selection initially. Since then, more and more map generators have been added and existing map generators have been improved over time. From this point on, there is no longer a single “version” of the map generator and the concept of a map generator “version” no longer applies. Each map generator is now developed independently. It is important to understand that the mapgens v5 and v6 should not be viewed as inferior to v7, instead they should just be viewed as different mapgens. “v5”, “v6” and “v7” are now just names, not version numbers. All mapgens currently included in Minetest regularily receive bugfixes and new features. |
| + | |||
| + | In Minetest 0.4.15, v7 became the new default selection. | ||
| − | + | === v6 === | |
| + | [[File:Mapgen_v6.jpg|thumb|650px|Mapgen v6 in Minetest 0.4.13-dev]] | ||
| + | The mapgen “v6” (also known as “mgv6”) is the direct continuation of [[#Version 6|version 6]] (before support for multiple mapgens has been added) and has pretty much the same features. In Minetest 0.4.13, support for snow biomes and ice sheets has been introduced to v6. This mapgen it is still officially supported in Minetest, it will not be removed anytime soon and improvements and bugfixes are still applied from time to time. | ||
| − | |||
| − | |||
| − | |||
{{-}} | {{-}} | ||
=== singlenode === | === singlenode === | ||
[[File:Mapgen_singlenode.jpg|thumb|650px|singlenode mapgen in Minetest 0.4.13]] | [[File:Mapgen_singlenode.jpg|thumb|650px|singlenode mapgen in Minetest 0.4.13]] | ||
| − | This mapgen was introduced in Minetest 0.4.6 by [[celeron55]]. It creates a world with only [[Air]] (can be changed with configuration) and is intended to be used by [[mods]] and [[ | + | This mapgen was introduced in Minetest 0.4.6 by [[celeron55]]. It creates a world with only [[Air]] (can be changed with configuration) and is intended to be used by [[mods]] and [[games]] for making custom map generators, so they can start completely from scratch. The name “singlenode” means that it generates a ''single'' type of ''node'' everywhere, [[Air]] by default. |
| − | + | This map generator has been hidden from the map generator selection screen for a couple of versions up to 0.4.16, in which it has been re-enabled again.{{-}} | |
| − | {{-}} | ||
=== indev === | === indev === | ||
| − | This mapgen was introduced in Minetest 0.4.6 by proller and contained many experimental features. It is based on v6. Major new features included | + | This mapgen was introduced in Minetest 0.4.6 by proller and contained many experimental features. It is based on v6. Major new features included floating islands at Y=500 and above, rare huge caves, and a more extreme terrain near the [[world boundaries]] in form of larger biomes, higher mountains and deeper oceans. It has been removed in version 0.4.10 because it was considered to be of low quality. |
<gallery widths="400px" heights="256px"> | <gallery widths="400px" heights="256px"> | ||
| − | File:Mapgen_indev_spawn.jpg|Most of the surface in the indev mapgen is almost | + | File:Mapgen_indev_spawn.jpg|Most of the surface in the indev mapgen is almost indentical to v6 (Minetest 0.4.9) |
File:Mapgen_indev_floating_islands.jpg|Floating islands in indev mapgen, Minetest 0.4.9 | File:Mapgen_indev_floating_islands.jpg|Floating islands in indev mapgen, Minetest 0.4.9 | ||
| − | File:Mapgen_indev_edge.jpg|Extreme terrain and | + | File:Mapgen_indev_edge.jpg|Extreme terrain and a world boundary in indev mapgen, Minetest 0.4.9 |
| − | File:Mapgen_indev_edge_mountains.jpg|High mountains near | + | File:Mapgen_indev_edge_mountains.jpg|High mountains near the world boundaries in indev mapgen, Minetest 0.4.9 |
File:Mapgen_indev_huge_cave.jpg|A huge (and buggy) cave in indev mapgen, Minetest 0.4.9 | File:Mapgen_indev_huge_cave.jpg|A huge (and buggy) cave in indev mapgen, Minetest 0.4.9 | ||
</gallery> | </gallery> | ||
| Line 83: | Line 117: | ||
[[File:Mapgen v7 0 4 9.jpg|thumb|650px|Mapgen v7 in Minetest 0.4.9 without biomes]] | [[File:Mapgen v7 0 4 9.jpg|thumb|650px|Mapgen v7 in Minetest 0.4.9 without biomes]] | ||
[[File:Mapgen_v7.jpg|thumb|650px|Mapgen v7 in Minetest 0.4.13-dev with biomes]] | [[File:Mapgen_v7.jpg|thumb|650px|Mapgen v7 in Minetest 0.4.13-dev with biomes]] | ||
| − | Also called “mgv7”. It was introduced in Minetest 0.4.7 by kwolekr, in which the map generator was still unusable. It is notable for its large rivers at Sea level. Caves in v7 are also very different than in v6, they are generally much larger. | + | [[File:Mapgen v7 floatlands.jpg|thumb|650px|Floatlands of mapgen v7 in Minetest 0.4.15]] |
| + | Also called “mgv7”. It was introduced in Minetest 0.4.7 by kwolekr, in which the map generator was still unusable. This map generator uses a combination of 2D and 3D Perlin noise. It is notable for its large rivers at Sea level. Caves in v7 are also very different than in v6, they are generally much larger. | ||
This mapgen has a long history of development and has seen countless improvements over the Minetest versions. | This mapgen has a long history of development and has seen countless improvements over the Minetest versions. | ||
* Initially, it only created worlds mostly made out of stone. Biomes for v7 were eventually added to Minetest Game at a later point | * Initially, it only created worlds mostly made out of stone. Biomes for v7 were eventually added to Minetest Game at a later point | ||
| − | * In Minetest 0.4.13, many big improvements to the terrain generation and noise parameters have been made; sandstone and desert stone dungeons | + | * In Minetest 0.4.13, many big improvements to the terrain generation and noise parameters have been made; sandstone and desert stone dungeons have been added as well |
| − | * | + | * In Minetest 0.4.14, the Biome API was introduced for v7 which makes v7 the first map generator which supports the Biome API, i.e. biomes defined by mods. The days of the stone worlds are over. Also, caves have been improved |
| − | * In Minetest 0.4.15, v7 became the default selected mapgen. Optional support for floating islands at Y=1280 and above was added, but is turned off by default. River channels can also carve through mountains | + | * In Minetest 0.4.15, v7 became the default selected mapgen. Optional and experimental support for huge floating islands at Y=1280 and above was added, but is turned off by default. River channels can also carve through mountains |
{{-}} | {{-}} | ||
| Line 99: | Line 134: | ||
This map generator has been removed in Minetest 0.4.10 when proller left the project because it was considered to be of very low quality and had many obvious lighting problems ([https://forum.minetest.net/viewtopic.php?f=3&t=7256#p148920]). | This map generator has been removed in Minetest 0.4.10 when proller left the project because it was considered to be of very low quality and had many obvious lighting problems ([https://forum.minetest.net/viewtopic.php?f=3&t=7256#p148920]). | ||
| + | |||
| + | The math mapgen is being continued in [[Overview_of_Minetest_forks#Freeminer|Freeminer]], a fork of Minetest. | ||
{{-}} | {{-}} | ||
| − | === v5 | + | === v5 === |
[[File:Mapgen_v5.jpg|thumb|650px|Modernized mapgen v5 in Minetest 0.4.13-dev]] | [[File:Mapgen_v5.jpg|thumb|650px|Modernized mapgen v5 in Minetest 0.4.13-dev]] | ||
| − | Also called “mgv5”. This is | + | Also called “mgv5”. This mapgen is a revival of the [[#Version 5|historic map generator version 5]] from Minetest-c55 0.3. In Minetest 0.4.11, this historic map generator has been revived by paramat because of its iconic terrain shape. |
| − | But this mapgen is not identical to the historic version 5. The terrain shape is identical | + | But this mapgen is not identical to the historic version 5. The terrain shape is ''nearly'' identical to the historic version. The main difference is that the modernized v5 map generator has mod-defined biome support (like v7), rather than predefined biomes. It also shares many other features with v7 which are not related to the terrain, for example desert and sandstone dungeons. Some features which have been added to v7 were often also added to v5. |
{{-}} | {{-}} | ||
| Line 112: | Line 149: | ||
Introduced in Minetest 0.4.13 by paramat. It creates worlds based on fractals, specifically those based on 3D and 4D Mandelbrot and Julia sets, including a mandelbulb. As of version 0.4.15, there are 18 variants which this mapgen supports. This mapgen has a similar intention like the old math mapgen, but it has a very different feature set compared to math. | Introduced in Minetest 0.4.13 by paramat. It creates worlds based on fractals, specifically those based on 3D and 4D Mandelbrot and Julia sets, including a mandelbulb. As of version 0.4.15, there are 18 variants which this mapgen supports. This mapgen has a similar intention like the old math mapgen, but it has a very different feature set compared to math. | ||
| + | {{-}} | ||
| + | |||
| + | === flat === | ||
| + | [[File:Mapgen_flat.jpg|thumb|650px|flat mapgen]] | ||
| + | The flat map generator was introduced in Minetest 0.4.14 by paramat. It can be used with or without biomes, decorations, caves, dungeons, etc. | ||
| + | |||
| + | Technically, Minetest was able to generate flat maps since 0.4.5 by using a mapgen setting (<code>mg_flags</code>). Later this flag has been removed from <code>mg_flags</code> and instead became a mapgen setting for v6 (<code>mgv6_spflags</code>) to generate flat maps in v6 style. | ||
{{-}} | {{-}} | ||
| Line 119: | Line 163: | ||
In Minetest Game, these rivers are made out of [[River Water]], a liquid which has been introduced in the same version for the rivers. It has been introduced because a liquid with a reduced flowing range was needed, as normal [[Water]] would easily flow over. | In Minetest Game, these rivers are made out of [[River Water]], a liquid which has been introduced in the same version for the rivers. It has been introduced because a liquid with a reduced flowing range was needed, as normal [[Water]] would easily flow over. | ||
| + | {{-}} | ||
| + | |||
| + | === carpathian === | ||
| + | [[File:Mapgen_carpathian.jpg|thumb|650px|carpathian mapgen in Minetest 0.5.0-dev-8221d3bc]] | ||
| + | Introduced in the developer version on 6th July 2017 by vlapsley. It has been first showcased [https://forum.minetest.net/viewtopic.php?f=9&t=17174 in the forums]. About 1.5 years later, it was finally released in a stable Minetest release: Minetest 5.0.0. This mapgen is notable for its complex mountains (multiple variants: terraced, stepped, very big, ridged) and hills. Vast flat plains, mountains and oceans dominate the landscape. Fjords are also possible, but rare. | ||
{{-}} | {{-}} | ||
| Line 124: | Line 173: | ||
* [[Map Generator]] | * [[Map Generator]] | ||
* [[Biomes]] | * [[Biomes]] | ||
| + | |||
[[Category:Map]] | [[Category:Map]] | ||
Latest revision as of 23:19, 22 October 2024
 Language: |
English • Bahasa Melayu |
|---|
This article shows the development history of the map generators in Luanti.
Development of a single map generator
Initially, Luanti (then called “Minetest-c55”, later “Minetest”) had only one map generator which was continously improved and had its own version number, where each version replaced the previous one. The earliest map generators are based on 2D Perlin noise.
Early development
Also dubbed “Version 0”, this section summarizes the earliest map generator experiments before the release of the first official map generator.
minetest-c55-101010000530
In the very first known version of Minetest-c55, there was just flat terrain made out of grass blocks with stone pyramids on top. There were a few holes. There were no other blocks or caves. The terrain was always the same.
minetest-c55-101017205222
The terrain was no longer flat and the pyramids are gone. The terrain generation was horrible, but at least terrain could be generated. It consisted of grass blocks and stone at surface. Very simple squareish caves could be found below the surface. The terrain was still not random.
minetest-c55-101024231736
Water has been added and forms oceans at a fixed sea level.
minetest-c55-101101170627 (and later)
Trees with leaves were added in, but they were very basic. Bushes (a single leaves block on the ground) were added as well. These primitive bushes have been removed in a later version.
Version 1
The first official mapgen was introduced in Minetest-c55 0.0.1. Features:
- Simple, random terrain with stone and dirt with grass
- Dirt generates below water and at some beaches
- Trees (consisting of Tree and Leaves)
- Simple lakes and oceans at a fixed sea level
- Simple caves and ravines (vertical caves)
- First ores: Mese blocks and coal ores are generated underground
Version 2 dev3
Mountains were made more pronounced, ore generation was better and trees have been improved. Although this was a development version.
Version 2 dev4
Things were tuned a little better.
Version 2
Sand has been added and formed sand beaches. A simple mud flow algorithm smoothens out dirt / dirt with grass hills. The cave generation has seen notable improvements and iron ore has been added as well.
Version 3 "3d noise"
3D Perlin noise is used to generate this terrain.
Version 4
More tweaking.
Version 5
Official map generation for version 0.3.1. It still uses 3D Perlin noise like the previous versions and is iconic for its extreme and often “blobby” terrain. In the 0.3 versions, this map generator hat predefined biomes like the current v6 map generator. In Minetest-c55 0.4, it was removed, but has been revived later (→#v5).
This version of the map generator is also used in Voxelands, a fork of Minetest-c55.
Version 6
Version 6 of the map generator was introduced in Minetest-c55 0.4.0 to replace the map generator version 5. This version uses 2D Perlin noise again and the terrain is now much smoother and more realistic than of the previous version. Map generation has also become much faster.
This version introduces jungles, deserts and rare gravel fields.
Version 6 was the last version of the only map generator before support for multiple map generators has been added. This mapgen has then directly be continued under the name “v6”.
Development of multiple map generators
Since Minetest 0.4.6, players are able to choose one of multiple map generators, with v6 being the default selection initially. Since then, more and more map generators have been added and existing map generators have been improved over time. From this point on, there is no longer a single “version” of the map generator and the concept of a map generator “version” no longer applies. Each map generator is now developed independently. It is important to understand that the mapgens v5 and v6 should not be viewed as inferior to v7, instead they should just be viewed as different mapgens. “v5”, “v6” and “v7” are now just names, not version numbers. All mapgens currently included in Minetest regularily receive bugfixes and new features.
In Minetest 0.4.15, v7 became the new default selection.
v6
The mapgen “v6” (also known as “mgv6”) is the direct continuation of version 6 (before support for multiple mapgens has been added) and has pretty much the same features. In Minetest 0.4.13, support for snow biomes and ice sheets has been introduced to v6. This mapgen it is still officially supported in Minetest, it will not be removed anytime soon and improvements and bugfixes are still applied from time to time.
singlenode
This mapgen was introduced in Minetest 0.4.6 by celeron55. It creates a world with only Air (can be changed with configuration) and is intended to be used by mods and games for making custom map generators, so they can start completely from scratch. The name “singlenode” means that it generates a single type of node everywhere, Air by default.
This map generator has been hidden from the map generator selection screen for a couple of versions up to 0.4.16, in which it has been re-enabled again.
indev
This mapgen was introduced in Minetest 0.4.6 by proller and contained many experimental features. It is based on v6. Major new features included floating islands at Y=500 and above, rare huge caves, and a more extreme terrain near the world boundaries in form of larger biomes, higher mountains and deeper oceans. It has been removed in version 0.4.10 because it was considered to be of low quality.
Most of the surface in the indev mapgen is almost indentical to v6 (Minetest 0.4.9)
Floating islands in indev mapgen, Minetest 0.4.9
Extreme terrain and a world boundary in indev mapgen, Minetest 0.4.9
High mountains near the world boundaries in indev mapgen, Minetest 0.4.9
A huge (and buggy) cave in indev mapgen, Minetest 0.4.9
v7
Also called “mgv7”. It was introduced in Minetest 0.4.7 by kwolekr, in which the map generator was still unusable. This map generator uses a combination of 2D and 3D Perlin noise. It is notable for its large rivers at Sea level. Caves in v7 are also very different than in v6, they are generally much larger.
This mapgen has a long history of development and has seen countless improvements over the Minetest versions.
- Initially, it only created worlds mostly made out of stone. Biomes for v7 were eventually added to Minetest Game at a later point
- In Minetest 0.4.13, many big improvements to the terrain generation and noise parameters have been made; sandstone and desert stone dungeons have been added as well
- In Minetest 0.4.14, the Biome API was introduced for v7 which makes v7 the first map generator which supports the Biome API, i.e. biomes defined by mods. The days of the stone worlds are over. Also, caves have been improved
- In Minetest 0.4.15, v7 became the default selected mapgen. Optional and experimental support for huge floating islands at Y=1280 and above was added, but is turned off by default. River channels can also carve through mountains
math
The mapgen “math” was introduced in Minetest 0.4.8 by proller. This was really a collection of 3 different map generators based on simple maths. It was capable of creating Menger sponges, mandelboxes and spheres. Mods could adds biomes with Minetest's biome API, but this was never used in Minetest Game, so only stone worlds were created by default.
This map generator has been removed in Minetest 0.4.10 when proller left the project because it was considered to be of very low quality and had many obvious lighting problems ([1]).
The math mapgen is being continued in Freeminer, a fork of Minetest.
v5
Also called “mgv5”. This mapgen is a revival of the historic map generator version 5 from Minetest-c55 0.3. In Minetest 0.4.11, this historic map generator has been revived by paramat because of its iconic terrain shape.
But this mapgen is not identical to the historic version 5. The terrain shape is nearly identical to the historic version. The main difference is that the modernized v5 map generator has mod-defined biome support (like v7), rather than predefined biomes. It also shares many other features with v7 which are not related to the terrain, for example desert and sandstone dungeons. Some features which have been added to v7 were often also added to v5.
fractal
Introduced in Minetest 0.4.13 by paramat. It creates worlds based on fractals, specifically those based on 3D and 4D Mandelbrot and Julia sets, including a mandelbulb. As of version 0.4.15, there are 18 variants which this mapgen supports. This mapgen has a similar intention like the old math mapgen, but it has a very different feature set compared to math.
flat
The flat map generator was introduced in Minetest 0.4.14 by paramat. It can be used with or without biomes, decorations, caves, dungeons, etc.
Technically, Minetest was able to generate flat maps since 0.4.5 by using a mapgen setting (mg_flags). Later this flag has been removed from mg_flags and instead became a mapgen setting for v6 (mgv6_spflags) to generate flat maps in v6 style.
valleys
Introduced in Minetest 0.4.14 by Duane Robertson. It is notable for its “valley”-like shapes and its flowing rivers. These rivers are very different than in v7: They flow downhill rather than being flat at ocean level.
In Minetest Game, these rivers are made out of River Water, a liquid which has been introduced in the same version for the rivers. It has been introduced because a liquid with a reduced flowing range was needed, as normal Water would easily flow over.
carpathian
Introduced in the developer version on 6th July 2017 by vlapsley. It has been first showcased in the forums. About 1.5 years later, it was finally released in a stable Minetest release: Minetest 5.0.0. This mapgen is notable for its complex mountains (multiple variants: terraced, stepped, very big, ridged) and hills. Vast flat plains, mountains and oceans dominate the landscape. Fjords are also possible, but rare.