Custom world generation

Custom world generation allows data packs to change how the world generates.

World preset and dimension

A world preset controls what dimensions a world has. Before 1.19 (22w11a), dimensions were defined in the dimension folder rather than in the world preset. Although in the current version the world preset is recommended, the dimension folder is still supported.

A world preset or dimension define what generator (noise, debug or superflat) is used in a dimension. If it is noise, they define what noise settings and biomes are used and how the biomes are placed.

Noise settings

Noise settings are for generating the shape of the terrain and noise caves, and what blocks the terrain is generated with. They are used by the minecraft:noise generator in a dimension.

Density function

A density function provides position-dependent values for the noise router.

Noise

A noise can be referenced by a density function and surface rule.

Biome

A biome is a region in a dimension with distinct features, carvers, climates, spawned mobs, ambient sound and music, and sky, water, grass and foliage colors.

Carver

Carvers are used to add carver caves and canyons. Note that noise caves are generated by noise settings.

Features

Features are small decorations that can at most write to a 3×3 chunk area centered on the placement chunk. They're locally placed per chunk and cannot be searched for using commands. Examples are trees, flowers, ore, etc.

Structure

Structures are large decorations that can at most write to a 256×256×256 block area centered on the structure start. They're placed globally and spaced out in a randomized grid (or in concentric rings for strongholds), and can be scanned for and found using /locate. Structures can affect terrain shaping by adding or removing terrain around structure pieces.

History

[hide]Java Edition
1.16.2			20w28a				Added support for custom world generation.
							Added template for custom world generation on GitHub.
1.16.2			20w29a				Noise settings can also be changed in worldgen.
1.18.2			22w06a				Added tag field to structure noise settings.
			1.18.2 Pre-release 1				Added noise_router to noise settings.
							Moved structure generation settings to separate files from noise settings.
1.19			22w11a				Added spawn_target field in noise settings, which is a list of climate target points.
							Removed the terrain_shaper field in the noise field in noise settings. The terrain shaper splines have been moved to density functions.
			22w12a				Removed the top_slide, bottom_slide and sampling fields in the noise field in noise settings. Instead, these configurations are moved to density functions.
1.19.3			22w42a				World generation data now stored in data/minecraft/worldgen in client.jar.
							Template for custom world generation on GitHub no longer updates.