Minecraft:Custom

Custom is a Minecraft:world type that allows users to change the generation of the Minecraft:Overworld, Minecraft:Nether, and Minecraft:End dimensions as well as the ability to create custom dimensions. It is edited using a Minecraft:JSON file that is imported on the world creation screen.

Access

To customize a world by using a JSON file, it needs to be imported before world creation:

• in the world creation menu, go to "More World Options..." and select the "Import Settings" option. Then, select a world generation Minecraft:JSON file. A warning appears saying that custom worlds are experimental. Click "Yes" to continue.
• then, in the world creation menu, the "World Type" button becomes gray and displays text: "World Type: Custom", so that the user is not able to change the world type anymore for the world being created.

The only way to access added dimensions is through commands, such as Template:Cmd, which teleports the player to the specified dimension (see Template:Slink).

JSON format

Template:Expand section Custom generation files take the following format:

• Template:Nbt The root tag.
  • Template:Nbt: Whether the world has a bonus chest or not (equivalent to the "Bonus chest" option).
  • Template:Nbt: Whether structures should be generated or not (equivalent to the "Generate structures" option).
  • Template:Nbt: The numerical seed of the world.
  • Template:Nbt: The custom world preset that was used to generate the world when it was an Minecraft:old customized world. Exists only for old customized worlds.
  • Template:Nbt: A list of the dimensions in this world where the key is the Minecraft:resource location of the dimension.
    • Template:Nbt A dimension. The dimensions Template:Code, Template:Code and Template:Code are required for a well functioning world. Any other resource location is allowed for custom dimensions.
      • Template:Nbt: Generation settings used for that dimension.
        • Template:Nbt: The ID of the generator. Can be Template:Code for a superflat dimension, Template:Code for noise generation, or Template:Code for a debug dimension.
        • Other compounds (see below)
      • Template:NbtTemplate:Nbt: The resource location of a dimension type file in a data pack, or one of the four default dimension types (Template:Code, Template:Code, Template:Code, Template:Code).

Generator types

• • Template:Nbt: The ID of the genarator. One of noise, flat, or debug.

    If Template:Nbt is Template:Code, additional fields are as follows:

  • Template:NbtTemplate:Nbt: Template:Json ref — Settings for the noise generator.
  • Template:Nbt: Settings dictating which biomes and biome shapes.
    • Template:Nbt: The type of biome generation. One of multi_noise, fixed, checkerboard, or the_end.

      If Template:Cd is multi_noise(3D biome generation used in the nether, and in the overworld in snapshot Minecraft:21w37a and after.) , additional fields are as follows:

    • Template:NbtTemplate:Nbt: (mutually exclusive with Template:Nbt) An ID or an object of a multi-noise biome source parameter list.
    • Template:Nbt: (mutually exclusive with Template:Nbt) (Cannot be empty) A parameter list of biomes, including their IDs and target noise parameters.
      • Template:Nbt: A biome and its properties.
        • Template:Nbt: Template:Json ref — The biome to place at the given parameters. A single id may be repeated several times with different parameters.
        • Template:Nbt: Represent optimal intervals for where the biome should be placed. These values do not affect the generation of terrain within biomes, instead, they only affect where the game chooses to place biomes. Thinking of a six-dimensional space, in the space these intervals are defined for biomes. If the six parameters at a location based on the noise router in noise settings fall into an interval, the corresponding biome is generated here. If the six parameters at a location do not fall into a defined biome interval in this list, it uses the closest biome interval to the 6D parameter point, in order to form a transition between biomes. Parameter combinations should be unique in the biomes list.
          • Template:Nbt: Not to be confused with the temperature value listed on Minecraft:Biome.
            • Template:Nbt: Value between -2.0 and 2.0 (both inclusive). The min value.
            • Template:Nbt: Value between -2.0 and 2.0 (both inclusive). The max value. Must be not less than min
          • Template:Nbt: Shorthand of Template:Nbt.
            • Template:Nbt: Value between -2.0 and 2.0 (both inclusive). The min value.
            • Template:Nbt: Value between -2.0 and 2.0 (both inclusive). The max value. Must be not less than min
          • Template:Nbt: Value between -2.0 and 2.0 (both inclusive). Shorthand of Template:Nbt when the min equals to the max.
          • Template:NbtTemplate:NbtTemplate:Nbt: The format is the same as temperature.
          • Template:NbtTemplate:NbtTemplate:Nbt: The format is the same as temperature.
          • Template:NbtTemplate:NbtTemplate:Nbt: The format is the same as temperature.
          • Template:NbtTemplate:NbtTemplate:Nbt: The format is the same as temperature.
          • Template:NbtTemplate:NbtTemplate:Nbt: The format is the same as temperature.
          • Template:Nbt: Value between 0.0 and 1.0 (both inclusive). Similar to the other parameters but is 0 everywhere. thus setting this parameter nearer to 0 leads to a greater edge over others, all else being equal.

      If Template:Cd is the_end(Biome generation used in the end with biome Template:Code in the center and other end biomes around) , no additional field.

      If Template:Cd is fixed(single biome) , additional fields are as follows:

    • Template:Nbt: The ID of the single biome to generate.

      If Template:Cd is checkerboard(A biome generation in which biomes are square (or close to square) and repeat along the diagonals) , additional fields are as follows:

    • Template:NbtTemplate:Nbt: Template:Json ref Biomes that repeat along the diagonals.
    • Template:Nbt: (optional, defaults to 2) Value between 0 and 62 (both inclusive). Determines the size of the squares on an exponential scale.

    If Template:Nbt is Template:Code(used for Minecraft:Debug world generation) , no additional fields.

    If Template:Nbt is Template:Code(used for Minecraft:Superflat world generation) , additional fields are as follows:

  • Template:Nbt: Superflat settings.
    • Template:Nbt: (Required, but can be empty) Layer settings. This list is interpreted from top to bottom, starting at world bottom.
      • Template:Nbt: A superflat layer.
        • Template:Nbt: The height of this layer. Value between 0 and 4064 (both inclusive) .
        • Template:Nbt: (optional, defaults to minecraft:air) The block ID.
    • Template:Nbt: (optional, defaults to plains) The ID of the single biome of the world.
    • Template:Nbt: (optional, defaults to false) Whether or not to generate lava lakes. If set to true, then lava lakes (lake_lava_underground and lake_lava_surface) generate often even in biomes where lakes don't normally generate.
    • Template:Nbt: (optional, defaults to false) Whether or not to generate biome-specific placed features. Note that the placed features in the step UNDERGROUND_STRUCTURES and SURFACE_STRUCTURES never generates. If the biome is not minecraft:void, but Template:Nbt is empty or has only air, no placed feature generates.
    • Template:NbtTemplate:Nbt: (optional, defaults to all the structure sets) List of structure sets to use. Can be a ID of structure set or a structure set tag, or a list of structure set IDs.

Defaults

Moved to Minecraft:Custom world generation#Noise settings

Noise generator preset defaults

These are the settings used by the 6 presets available for the minecraft:noise generator.

Property			minecraft:overworld	minecraft:amplified	minecraft:nether	minecraft:caves	minecraft:end	minecraft:floating_islands
bedrock_roof_position			-10		0		-10
bedrock_floor_position			0		0		-10
sea_level			63		32		0
disable_mob_generation			false		false		true	false
default_block			minecraft:stone		minecraft:netherrack	minecraft:stone	minecraft:end_stone	minecraft:stone
default_fluid			minecraft:water		minecraft:lava	minecraft:water	minecraft:air	minecraft:water
structures	stronghold	distance	32		Tag not included		Tag not included
		count	1
		spread	3
	structures		See below
noise	top_slide	target	-10		120		-3000
		size	3		3		64
		offset	0		0		-46
	bottom_slide	target	-30		320		-30
		size	0		4		7
		offset	0		-1		1
	sampling	xz_scale	0.9999999814507745		1		2
		xz_factor	80		80		80
		y_scale	0.9999999814507745		3		1
		y_factor	160		60		160
	size_vertical		2		2		1
	size_horizontal		1		1		2
	height		256		128		128
	density_factor		1		0		0
	density_offset		-0.46875		0.019921875		0
	random_density_offset		true		false		false
	simplex_surface_noise		true		false		true
	island_noise_override		false		false		true	false
	amplified		false	true	false		false

Structure defaults

These are the default values for all namespaced structures. Every preset uses the same values for all of these structures, with the exception of minecraft:ruined_portal.

Structure		Spacing	Separation	Salt
village		32	8	10387312
desert_pyramid		32	8	14357617
igloo		32	8	14357618
jungle_pyramid		32	8	14357619
swamp_hut		32	8	14357620
pillager_outpost		32	8	165745296
stronghold*		1	0	0
monument		32	5	10387313
endcity		20	11	10387313
mansion		80	20	10387319
buried_treasure**		1	0	0
mineshaft**		1	0	0
ruined_portal	nether and caves	25	10	34222645
	All other presets	40	15	34222645
shipwreck		24	4	165745295
ocean_ruin		20	8	14357621
bastion_remnant		27	4	30084232
fortress		27	4	30084232
nether_fossil		2	1	14357921

*Placeholder values, have no effect

**Salt values aren't used for theses structures; changing them produces no effect

Biome parameter defaults

Template:Update These are the default values used for each biome in the multi_noise biome_source. Interestingly, although only the values for nether biomes are accessible through a preset, several overworld biomes have default values as well.

Biome	Temperature	Humidity	Altitude	Weirdness	Offset
badlands	-0.25	-0.5	0.5	0.2	1
badlands_plateau	-0.25	-0.5	0.65	0.2	1
bamboo_jungle	0.5	0.5	0	0.2	1
bamboo_jungle_hills	0.5	0.5	0.25	0.2	1
basalt_deltas	-0.5	0	0	0	0.175
beach	0	0	-0.1	0	0.9935
birch_forest	-0.1	0.2	0	0	1
birch_forest_hills	-0.1	0.2	0.25	0	1
crimson_forest	0.4	0	0	0	0
desert	0.5	-0.5	0	0	1
jungle	0.5	0.5	0	0	1
nether_wastes	0	0	0	0	0
ocean	0	0	-0.5	0	1
plains	0	0	0	0	1
snowy_tundra	-0.5	-0.5	0	0	1
soul_sand_valley	0	-0.5	0	0	0
warm_ocean	0	0	-0.25	0	1
warped_forest	0	0.5	0	0	0.375

Examples

Default settings

This one will change to 1.19.3-typed later.

The following is the settings for an exported default Minecraft world. Template:Collapse

Expanded default settings

This file contains the same settings used to produce a default world, but with all of the presets expanded to their default values. Note that there is a bug that makes it impossible to create the Minecraft:ender dragon fight without using the dimension type preset minecraft:the_end, as the flag that creates the fight is hardcoded and not accessible through JSON. However, it is otherwise identical to the default world.Template:Collapse

Custom superflat dimension

File:Custom superflat dimension.png

An overview of a world made with the adjacent settings.

This dimension is a Minecraft:Superflat world with a layer of grass on four layers of coarse dirt on top of five layers of basalt. The entire world is full of village houses as Template:Cd is set to 3 (default: 32) and Template:Cd is set to 1 (default: 8). The world starts by default at time 1000. Template:Collapse

Gallery

Screenshots

• Natural Minecraft:snow generating as high as Y=801 in an Minecraft:amplified custom world with increased maximum height.
  Natural Minecraft:snow generating as high as Y=801 in an Minecraft:amplified custom world with increased maximum height.
• Minecraft:Bedrock floor generating as low as Y=−2048 in a world with decreased min_y.
  Minecraft:Bedrock floor generating as low as Y=−2048 in a world with decreased min_y.
• Lowest placeable temporary block in a custom world, at which point the game is unplayable.
  Lowest placeable temporary block in a custom world, at which point the game is unplayable.

External links

• Example settings
• Detailed guide of the generator settings
• JSON generator website

See also

• Minecraft:Custom dimension
• Minecraft:Custom world generation