Placement modifier

Drops positions whose biome doesn't list this feature. Vanilla ends most placements with it.

Biome()

Keeps positions where a block predicate passes, such as Solid() or MatchingBlocks(air).

BlockPredicateFilter(predicate)

predicate

BlockPredicate

Repeats each position count times. Follow it with InSquare() to spread the copies over the chunk.

Count(count)

count

IntProvider of int 0..4096

How many: a number, or a range such as 2..5.

PlacedFeature trees { feature = minecraft:oak, placement = [Count(3), InSquare(), Heightmap(WORLD_SURFACE_WG), Biome()] }

Places count positions on each layer of the terrain, from the top down, so features appear under overhangs too. Vanilla nether forests use it.

CountOnEveryLayer(count)

count

IntProvider of int 0..256

Cuboid(xz_size, y_size, include_interior?, include_edges?)

xz_size

IntProvider of int 1..16

y_size

IntProvider of int 1..16

include_interioroptional

bool

Defaults to true.

include_edgesoptional

bool

Defaults to true.

Moves each position up or down, at most max_steps blocks, until target_condition passes. Drops it if nothing is found.

EnvironmentScan(direction_of_search, max_steps, target_condition, allowed_search_condition?)

direction_of_search

VerticalDirection

up or down.

max_steps

int 1..32

How far to search, in blocks.

target_condition

BlockPredicate

The block predicate to search for.

allowed_search_conditionoptional

BlockPredicate

The scan stops if a block on the way fails this.

Replaces each position with a fixed list of positions.

FixedPlacement(positions)

positions

list of (list of int (exactly 3))

Fixed list of block positions to place the feature at.

Sets each position's Y to a height picked by a height provider.

HeightRange(height)

height

HeightProvider

The height, such as Uniform(AboveBottom(0), Absolute(64)).

Moves each position up or down onto the surface of a heightmap, such as WORLD_SURFACE_WG for the top block or OCEAN_FLOOR_WG for the sea floor.

Heightmap(heightmap)

heightmap

HeightmapType

Which surface to use.

Moves each position to a random x and z within its chunk.

InSquare()

Repeats each position a number of times that follows a noise, so features cluster in some areas. The count is ceil((noise + noise_offset) * noise_to_count_ratio).

NoiseBasedCount(noise_to_count_ratio, noise_factor, noise_offset?)

noise_to_count_ratio

int

Multiplies the noise to get the count.

noise_factor

number

Divides x and z before sampling; larger values give larger clusters.

noise_offsetoptional

number

Repeats each position below_noise times where a noise is below noise_level, and above_noise times where it is above.

NoiseThresholdCount(noise_level, below_noise, above_noise)

noise_level

number

below_noise

int

above_noise

int

Moves each position by the given number of blocks.

Offset(x, y, z)

x

IntProvider of int -16..16

y

IntProvider of int -16..16

z

IntProvider of int -16..16

Keeps each position with probability chance, from 0 to 1.

RandomChance(chance)

chance

number 0..1

RandomlySelected(placements)

placements

list of PlacementModifier (at least 1)

Keeps each position with a chance of 1 in chance.

RarityFilter(chance)

chance

int 0..

Keep one position in this many, on average.

PlacedFeature rare_rocks { feature = minecraft:forest_rock, placement = [RarityFilter(16), InSquare(), Heightmap(MOTION_BLOCKING), Biome()] }

Keeps positions whose Y, measured from a heightmap's surface, is from min_inclusive to max_inclusive.

SurfaceRelativeThresholdFilter(heightmap, min_inclusive?, max_inclusive?)

heightmap

HeightmapType

min_inclusiveoptional

int

max_inclusiveoptional

int

Keeps positions where the water above the surface is at most max_water_depth blocks deep.

SurfaceWaterDepthFilter(max_water_depth)

max_water_depth

int