Toggle menu
Toggle preferences menu
Toggle personal menu
Not logged in
Your IP address will be publicly visible if you make any edits.

Minecraft:Anomalous world seeds: Difference between revisions

From SAS Gaming Wiki
SyncBot (talk | contribs)
Remove broken links to missing pages
SyncBot (talk | contribs)
Fix template calls: add MC/ prefix
 
Line 1: Line 1:
{{wip}}
{{MC/WIP}}
Certain [[Minecraft:world seed]]s are known for producing unexpected results when used for generating worlds, often due to interacting with random number generators in certain ways.
Certain [[Minecraft:world seed]]s are known for producing unexpected results when used for generating worlds, often due to interacting with random number generators in certain ways.


== Diagonal feature repetition ==
== Diagonal feature repetition ==
{{info needed section|Why does in earlier Java Edition versions, did only the first of each seed list in Matthew's video<ref name="Bolan1">{{ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> seem to actually work?}}
{{info needed section|Why does in earlier Java Edition versions, did only the first of each seed list in Matthew's video<ref name="Bolan1">{{MC/Ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> seem to actually work?}}
[[File:Endlesscanyon wideangle.png|thumb|Seed 1669320484 in [[Bedrock Edition]], with repeating canyons. The coordinates of this screenshot are -1265, 300, 0.]]
[[File:Endlesscanyon wideangle.png|thumb|Seed 1669320484 in [[Bedrock Edition]], with repeating canyons. The coordinates of this screenshot are -1265, 300, 0.]]
It is possible for feature generation, specifically that which governs objects such as trees, ores, lakes and other similar minor structures, to repeat diagonally if certain values happen to equal each other or one to equal the other's negative.<ref name="Bolan1">{{ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> For example, {{in|JE}} before 1.18, the seed {{code|102496288339226}} will cause features to repeat along the positive-positive diagonal, and the seed {{code|74811678275130}} will cause them to repeat along the positive-negative diagonal. Prior to Java Edition Beta 1.8, [[Minecraft:cave]]s were also affected by this diagonal repetition.
It is possible for feature generation, specifically that which governs objects such as trees, ores, lakes and other similar minor structures, to repeat diagonally if certain values happen to equal each other or one to equal the other's negative.<ref name="Bolan1">{{MC/Ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> For example, {{MC/In|JE}} before 1.18, the seed {{MC/Code|102496288339226}} will cause features to repeat along the positive-positive diagonal, and the seed {{MC/Code|74811678275130}} will cause them to repeat along the positive-negative diagonal. Prior to Java Edition Beta 1.8, [[Minecraft:cave]]s were also affected by this diagonal repetition.


What appears to be the exact same effect can be seen {{in|BE}} with different seeds. The seeds {{code|1669320484}} and {{code|289849025}}, for example, cause trees, monster rooms, amethyst geodes and world decorations to repeat on the positive-negative diagonal.<ref name="bedrockrepeat">{{bug|MCPE-95011}}</ref> It is not known if there are any seeds that cause repetition on the positive-positive diagonal.
What appears to be the exact same effect can be seen {{MC/In|BE}} with different seeds. The seeds {{MC/Code|1669320484}} and {{MC/Code|289849025}}, for example, cause trees, monster rooms, amethyst geodes and world decorations to repeat on the positive-negative diagonal.<ref name="bedrockrepeat">{{bug|MCPE-95011}}</ref> It is not known if there are any seeds that cause repetition on the positive-positive diagonal.


== Zero as output from pRNG function ==
== Zero as output from pRNG function ==
{{exclusive|java|section=1}}
{{MC/Exclusive|java|section=1}}
[[File:Duplicate Caves.png|thumb|Seed 164311266871034 in spectator mode. Caves are repetitive along the Z axis.]]
[[File:Duplicate Caves.png|thumb|Seed 164311266871034 in spectator mode. Caves are repetitive along the Z axis.]]
Java's built-in Math.random() function will output a pseudorandom value for any given input value; it is possible for this output value to be 0, just as any other number.<ref>https://stackoverflow.com/questions/3065554/can-javas-random-function-be-zero</ref> In such a case, certain types of population data for adjacent chunks will be changed by zero (i.e. unchanged), resulting in affected structures generating identically in adjacent chunks.<ref>{{bug|MC-111378||Math error (random generation of zero) causing map gen to fail|Won't Fix}}</ref> The structures primarily affected by this are carvers (caves, canyons, underwater caves and underwater canyons) and mineshafts. Certain aspects of feature placement, such as water lakes, also appear to suffer placement affected to a much more minor extent, which is most pronounced in controlled environments such as superflat worlds with features enabled.{{info needed|investigate this further}}
Java's built-in Math.random() function will output a pseudorandom value for any given input value; it is possible for this output value to be 0, just as any other number.<ref>https://stackoverflow.com/questions/3065554/can-javas-random-function-be-zero</ref> In such a case, certain types of population data for adjacent chunks will be changed by zero (i.e. unchanged), resulting in affected structures generating identically in adjacent chunks.<ref>{{bug|MC-111378||Math error (random generation of zero) causing map gen to fail|Won't Fix}}</ref> The structures primarily affected by this are carvers (caves, canyons, underwater caves and underwater canyons) and mineshafts. Certain aspects of feature placement, such as water lakes, also appear to suffer placement affected to a much more minor extent, which is most pronounced in controlled environments such as superflat worlds with features enabled.{{MC/Info needed|investigate this further}}


{{code|Random.nextDouble()}} will return a value of {{code|0}} on the first call if the provided value is {{code|107038380838084}}, on the second call if the value is {{code|164311266871034}}, and on the third call if the value is {{code|240144965573432}}.
{{MC/Code|Random.nextDouble()}} will return a value of {{MC/Code|0}} on the first call if the provided value is {{MC/Code|107038380838084}}, on the second call if the value is {{MC/Code|164311266871034}}, and on the third call if the value is {{MC/Code|240144965573432}}.
* In vanilla, the seed {{code|107038380838084}} will cause affected structures to repeat every chunk on the X-axis, and the seed {{code|164311266871034}} will cause affected structures to repeat every chunk on the Z-axis. The seed {{code|240144965573432}} does not appear to have any effects.
* In vanilla, the seed {{MC/Code|107038380838084}} will cause affected structures to repeat every chunk on the X-axis, and the seed {{MC/Code|164311266871034}} will cause affected structures to repeat every chunk on the Z-axis. The seed {{MC/Code|240144965573432}} does not appear to have any effects.
* When using certain mods such as [https://www.curseforge.com/minecraft/mc-mods/tall-worlds Tall Worlds] or [https://www.curseforge.com/minecraft/mc-mods/opencubicchunks OpenCubicChunks] which institute a three-dimensional chunk system, the seed {{code|107038380838084}} will cause affected structures to repeat every chunk on the X-axis, and the seed {{code|164311266871034}} will cause affected structures to repeat every chunk on the Y-axis, and the seed {{code|240144965573432}} will cause affected structures to repeat every chunk on the Z-axis.
* When using certain mods such as [https://www.curseforge.com/minecraft/mc-mods/tall-worlds Tall Worlds] or [https://www.curseforge.com/minecraft/mc-mods/opencubicchunks OpenCubicChunks] which institute a three-dimensional chunk system, the seed {{MC/Code|107038380838084}} will cause affected structures to repeat every chunk on the X-axis, and the seed {{MC/Code|164311266871034}} will cause affected structures to repeat every chunk on the Y-axis, and the seed {{MC/Code|240144965573432}} will cause affected structures to repeat every chunk on the Z-axis.


Certain carvers, for unknown reasons, use a salt of either -1 or -2 when generating. As a result, not all carver types will repeat in one given world. If we take the X-axis seed as an example:
Certain carvers, for unknown reasons, use a salt of either -1 or -2 when generating. As a result, not all carver types will repeat in one given world. If we take the X-axis seed as an example:
* {{code|107038380838084}} causes some carver caves to repeat, most often those near the surface
* {{MC/Code|107038380838084}} causes some carver caves to repeat, most often those near the surface
* {{code|107038380838083}} generally causes deeper underground carver caves to repeat
* {{MC/Code|107038380838083}} generally causes deeper underground carver caves to repeat
* {{code|107038380838082}} causes canyons to repeat; carver caves appear to be unaffected
* {{MC/Code|107038380838082}} causes canyons to repeat; carver caves appear to be unaffected


In general, if a data pack is used to add new carvers to generation, each carver type will have its own salt.
In general, if a data pack is used to add new carvers to generation, each carver type will have its own salt.


=== Integer overflow and higher periods ===
=== Integer overflow and higher periods ===
{{empty section}}
{{MC/Empty Section}}


== Non-orthogonal mineshaft repetition ==
== Non-orthogonal mineshaft repetition ==
{{empty section|Some information to include: Matthew's video<ref>{{ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> has two example seeds in the description. How do they do what they do?}}
{{empty section|Some information to include: Matthew's video<ref>{{MC/Ytl|UtNXUMrSIxQ|This Minecraft Seed Makes Everything Repeat|Matthew Bolan|January 5, 2020}}</ref> has two example seeds in the description. How do they do what they do?}}


== Possible BE biome color corruption ==
== Possible BE biome color corruption ==
{{empty section|Some information to include: See comment threads on https://www.reddit.com/r/MCPE/comments/5i6sae/recursive_infinite_mineshaft_seeds_on_mcpe/ and actually attempt to confirm this happens in game.}}
{{MC/Empty Section|Some information to include: See comment threads on https://www.reddit.com/r/MCPE/comments/5i6sae/recursive_infinite_mineshaft_seeds_on_mcpe/ and actually attempt to confirm this happens in game.}}


== Shadow seeds ==
== Shadow seeds ==
Line 44: Line 44:


== General information ==
== General information ==
{{Main|World seed}}
{{MC/Main|World seed}}
===Generation quirks ===
===Generation quirks ===
Through certain seeds, it is possible to observe interesting effects.
Through certain seeds, it is possible to observe interesting effects.
Line 51: Line 51:
Only certain sections of the seed are used to generate specific features within the world. It is possible to generate multiple worlds with identical cave systems, Nether biomes and other arrangements of generated structures simply by converting the seed into binary and tweaking the desired bits.<ref>https://www.minecraftforum.net/forums/minecraft-java-edition/seeds/2229720-can-two-different-seeds-produce-identical-worlds</ref> An example is the seed generator using only the first 48 bits to generate cave systems and badlands clay banding layers.
Only certain sections of the seed are used to generate specific features within the world. It is possible to generate multiple worlds with identical cave systems, Nether biomes and other arrangements of generated structures simply by converting the seed into binary and tweaking the desired bits.<ref>https://www.minecraftforum.net/forums/minecraft-java-edition/seeds/2229720-can-two-different-seeds-produce-identical-worlds</ref> An example is the seed generator using only the first 48 bits to generate cave systems and badlands clay banding layers.


Any seed calculated as {{code|4294967296 × n + 1669320484}} also generate maps with repeating features.
Any seed calculated as {{MC/Code|4294967296 × n + 1669320484}} also generate maps with repeating features.


==== Repetition ====
==== Repetition ====
{{IN|bedrock}}, Mineshaft generation repeats vertically in the seeds {{code|-1171867832}} and {{code|1000686894}}.{{more information needed|Why is this the case?}}
{{MC/In|bedrock}}, Mineshaft generation repeats vertically in the seeds {{MC/Code|-1171867832}} and {{MC/Code|1000686894}}.{{MC/More information needed|Why is this the case?}}


== History ==
== History ==
{{HistoryTable
{{HistoryTable
|{{HistoryLine|java infdev}}
|{{MC/HistoryLine|java infdev}}
|{{HistoryLine||20100616-1808|First version known to be affected by diagonal repetition seeds. Caves will repeat diagonally.}}
|{{MC/HistoryLine||20100616-1808|First version known to be affected by diagonal repetition seeds. Caves will repeat diagonally.}}
|{{HistoryLine||?|Trees also repeat diagonally on diagonal repetition seeds.{{info needed|Confirmed for inf-20100624, inconclusive earlier. Trees used to depend on a noise generator and it's uncertain as to when this was changed to be feature-based.}}}}
|{{HistoryLine||?|Trees also repeat diagonally on diagonal repetition seeds.{{MC/Info needed|Confirmed for inf-20100624, inconclusive earlier. Trees used to depend on a noise generator and it's uncertain as to when this was changed to be feature-based.}}}}
|{{HistoryLine|java beta}}
|{{MC/HistoryLine|java beta}}
|{{HistoryLine||1.8|dev=Pre-release|Caves have changed to no longer generate as features, and therefore no longer will repeat diagonally. They will instead now repeat orthogonally under a different class of "broken" seeds.}}
|{{MC/HistoryLine||1.8|dev=Pre-release|Caves have changed to no longer generate as features, and therefore no longer will repeat diagonally. They will instead now repeat orthogonally under a different class of "broken" seeds.}}
|{{HistoryLine|java}}
|{{MC/HistoryLine|java}}
|{{HistoryLine||1.13|dev=18w06a|Certain seeds, such as 82025653894727, would not repeat features diagonally in versions prior to this, but will do so from this version onwards. The exact reasoning for this is unknown.}}
|{{MC/HistoryLine||1.13|dev=18w06a|Certain seeds, such as 82025653894727, would not repeat features diagonally in versions prior to this, but will do so from this version onwards. The exact reasoning for this is unknown.}}
|{{HistoryLine|||dev=pre7|A salt of -1 has been implemented that causes underwater caves and non-underwater canyons to repeat on different seeds from non-underwater caves and underwater canyons.}}
|{{MC/HistoryLine|||dev=pre7|A salt of -1 has been implemented that causes underwater caves and non-underwater canyons to repeat on different seeds from non-underwater caves and underwater canyons.}}
|{{HistoryLine||1.17|dev=21w07a|Orthogonal repetition seeds now also affect the transition from stone to grimstone/deepslate, causing striking horizontal patterns not present in "normal" seeds.}}
|{{MC/HistoryLine||1.17|dev=21w07a|Orthogonal repetition seeds now also affect the transition from stone to grimstone/deepslate, causing striking horizontal patterns not present in "normal" seeds.}}
|{{HistoryLine|||dev=21w08a|A salt of -2 has been implemented alongside the introduction of crack carvers that causes them to repeat on different seeds from either caves or conventional canyons.}}
|{{MC/HistoryLine|||dev=21w08a|A salt of -2 has been implemented alongside the introduction of crack carvers that causes them to repeat on different seeds from either caves or conventional canyons.}}
|{{HistoryLine||1.18|dev=Experimental Snapshot 1|Crack carvers no longer exist. The -2 salt now affects all types of ravines instead.
|{{HistoryLine||1.18|dev=Experimental Snapshot 1|Crack carvers no longer exist. The -2 salt now affects all types of ravines instead.
|The seeds that cause underwater caves and non-underwater ravines to repeat now also appear to affect some other, presumably new non-underwater carvers.{{info needed|Which? Potentially related to whatever minecraft:cave_extra_underground is?}}}}
|The seeds that cause underwater caves and non-underwater ravines to repeat now also appear to affect some other, presumably new non-underwater carvers.{{MC/Info needed|Which? Potentially related to whatever minecraft:cave_extra_underground is?}}}}
|{{HistoryLine|||dev=Pre-release 7|All existing seeds featuring diagonal feature repetition appear to have been patched; while the phenomenon presumably still exists, no seeds exhibiting it from this version onward have been found.}}
|{{MC/HistoryLine|||dev=Pre-release 7|All existing seeds featuring diagonal feature repetition appear to have been patched; while the phenomenon presumably still exists, no seeds exhibiting it from this version onward have been found.}}
}}
}}


== References ==
== References ==
{{reflist}}
{{MC/Reflist}}


== Navigation ==
== Navigation ==
{{Navbox Java Edition technical|general}}
{{MC/Navbox Java Edition technical|general}}


[[Category:Java Edition technical]]
[[Category:Java Edition technical]]
[[Category:Bedrock Edition]]
[[Category:Bedrock Edition]]

Latest revision as of 19:01, 9 April 2026

  1. REDIRECT Template:Work in progress

Template:Redr Certain Minecraft:world seeds are known for producing unexpected results when used for generating worlds, often due to interacting with random number generators in certain ways.

Diagonal feature repetition

Template:Info needed section

File:Endlesscanyon wideangle.png
Seed 1669320484 in Bedrock Edition, with repeating canyons. The coordinates of this screenshot are -1265, 300, 0.

It is possible for feature generation, specifically that which governs objects such as trees, ores, lakes and other similar minor structures, to repeat diagonally if certain values happen to equal each other or one to equal the other's negative.<ref name="Bolan1">

  1. redirect Template:YouTube link

Template:Redr</ref> For example, in Template:Editions before 1.18, the seed 102496288339226 will cause features to repeat along the positive-positive diagonal, and the seed 74811678275130 will cause them to repeat along the positive-negative diagonal. Prior to Java Edition Beta 1.8, Minecraft:caves were also affected by this diagonal repetition.

What appears to be the exact same effect can be seen in Template:Editions with different seeds. The seeds 1669320484 and 289849025, for example, cause trees, monster rooms, amethyst geodes and world decorations to repeat on the positive-negative diagonal.<ref name="bedrockrepeat">Template:Bug</ref> It is not known if there are any seeds that cause repetition on the positive-positive diagonal.

Zero as output from pRNG function

Script error: No such module "Exclusive".

File:Duplicate Caves.png
Seed 164311266871034 in spectator mode. Caves are repetitive along the Z axis.

Java's built-in Math.random() function will output a pseudorandom value for any given input value; it is possible for this output value to be 0, just as any other number.<ref>https://stackoverflow.com/questions/3065554/can-javas-random-function-be-zero</ref> In such a case, certain types of population data for adjacent chunks will be changed by zero (i.e. unchanged), resulting in affected structures generating identically in adjacent chunks.<ref>Template:Bug</ref> The structures primarily affected by this are carvers (caves, canyons, underwater caves and underwater canyons) and mineshafts. Certain aspects of feature placement, such as water lakes, also appear to suffer placement affected to a much more minor extent, which is most pronounced in controlled environments such as superflat worlds with features enabled.​<more information needed></more information needed>

Random.nextDouble() will return a value of 0 on the first call if the provided value is 107038380838084, on the second call if the value is 164311266871034, and on the third call if the value is 240144965573432.

  • In vanilla, the seed 107038380838084 will cause affected structures to repeat every chunk on the X-axis, and the seed 164311266871034 will cause affected structures to repeat every chunk on the Z-axis. The seed 240144965573432 does not appear to have any effects.
  • When using certain mods such as Tall Worlds or OpenCubicChunks which institute a three-dimensional chunk system, the seed 107038380838084 will cause affected structures to repeat every chunk on the X-axis, and the seed 164311266871034 will cause affected structures to repeat every chunk on the Y-axis, and the seed 240144965573432 will cause affected structures to repeat every chunk on the Z-axis.

Certain carvers, for unknown reasons, use a salt of either -1 or -2 when generating. As a result, not all carver types will repeat in one given world. If we take the X-axis seed as an example:

  • 107038380838084 causes some carver caves to repeat, most often those near the surface
  • 107038380838083 generally causes deeper underground carver caves to repeat
  • 107038380838082 causes canyons to repeat; carver caves appear to be unaffected

In general, if a data pack is used to add new carvers to generation, each carver type will have its own salt.

Integer overflow and higher periods

  1. Redirect Template:Empty section

Non-orthogonal mineshaft repetition

Template:Empty section

Possible BE biome color corruption

  1. Redirect Template:Empty section

Shadow seeds

It is possible for different seeds to share major generational characteristics with other seeds through certain mechanisms.

Biome shadow seeds

In Java Edition before 1.18, by adding the constant -7379792620528906219 (in calculation) to the world seed, it was possible to obtain a "shadow seed". In this seed, biome arrangements were identical to the ones of the original seed, but locations of features (caves, hills) and generated structures (villages, temples, etc.) were different in the new seed.

Unused bits

In Minecraft:Java Edition before 1.18, the shapes of the biomes were generated using only the upper 24 bits of the world seed. Additionally, caves and badlands terracotta patterns only use the upper 48 bits of the world seed.

General information

{{#vardefine:params|0 }}Template:Hatnote

Generation quirks

Through certain seeds, it is possible to observe interesting effects.

Changing terrain without changing some structures

Only certain sections of the seed are used to generate specific features within the world. It is possible to generate multiple worlds with identical cave systems, Nether biomes and other arrangements of generated structures simply by converting the seed into binary and tweaking the desired bits.<ref>https://www.minecraftforum.net/forums/minecraft-java-edition/seeds/2229720-can-two-different-seeds-produce-identical-worlds</ref> An example is the seed generator using only the first 48 bits to generate cave systems and badlands clay banding layers.

Any seed calculated as 4294967296 × n + 1669320484 also generate maps with repeating features.

Repetition

in Template:Editions, Mineshaft generation repeats vertically in the seeds -1171867832 and 1000686894.

  1. REDIRECT Template:Info needed

History

Template:HistoryTable

References

<references group="">

 </references>

Navigation

Concepts
General format
World
Legacy
Level format
Legacy
.minecraft
Tools
Sound
Commands

All commands

Launching
Legacy
Protocol
Server
Protocols
Legacy
Components
Tag
GameTest
World generation
Noise settings
Structures
Removed
Data packs
Tutorials
Content
World generation

Template:Article other