World generation API

Overview

Regions Unexplored provides custom world generation components including feature types, foliage placers, and tree decorators. These systems extend Minecraft’s terrain generation with mod-specific structures and vegetation.

Foliage placers

Foliage placers determine the shape and placement of tree leaves. RU adds custom foliage placer types registered through RUFoliagePlacerTypes.

Registered foliage placers

RUFoliagePlacerTypes.java:13-14

Supplier<FoliagePlacerType<SakuraFoliagePlacer>> SAKURA = register("sakura", SakuraFoliagePlacer.TYPE);
Supplier<FoliagePlacerType<WillowFoliagePlacer>> WILLOW = register("willow", WillowFoliagePlacer.TYPE);

Sakura foliage placer

Creates asymmetric cherry blossom-style foliage with decorative flowers:

SakuraFoliagePlacer codec

public static final MapCodec<SakuraFoliagePlacer> CODEC = RecordCodecBuilder.mapCodec((placer) ->
    foliagePlacerParts(placer).and(placer.group(
        IntProvider.codec(4, 16).fieldOf("height").forGetter(
            (height) -> height.height),
        Codec.floatRange(0.0F, 1.0F).fieldOf("flower_decoration_chance").forGetter(
            (flowerChance) -> flowerChance.flowerDecorationChance)
    ))
    .apply(placer, SakuraFoliagePlacer::new)
);

SakuraFoliagePlacer

class

Custom foliage placer for sakura trees

Show constructor

Constructor signature

public SakuraFoliagePlacer(
    IntProvider radius,
    IntProvider offset,
    IntProvider height,
    float flowerDecorationChance
)

Show fields

height

IntProvider

Vertical height range for foliage (4-16 blocks)

flowerDecorationChance

float

Probability of flower decorations (0.0-1.0)

Foliage placement logic

The Sakura placer creates asymmetric leaf patterns:

Placement methods

protected void createFoliage(
    LevelSimulatedReader level,
    FoliageSetter setter,
    RandomSource random,
    TreeConfiguration treeConfig,
    int p_272975_,
    FoliageAttachment foliage,
    int p_273647_,
    int p_273700_,
    int height
) {
    BlockPos blockpos = foliage.pos().above(height);
    if (random.nextInt(2) == 0) {
        placeLeavesBlobLeft(level, setter, random, treeConfig, blockpos);
    } else {
        placeLeavesBlobRight(level, setter, random, treeConfig, blockpos);
    }
}

Willow foliage placer

Creates drooping willow-style foliage:

The willow foliage placer creates hanging leaf patterns characteristic of weeping willow trees.

Tree decorators

Tree decorators add additional blocks or features to generated trees. RU provides several custom decorator types.

Registered decorators

RUTreeDecoratorTypes.java:12-15

Supplier<TreeDecoratorType<BlackwoodBioshroom>> BLACKWOOD_BIOSHROOMS = 
    register("blackwood_bioshrooms", BlackwoodBioshroom.TYPE);
Supplier<TreeDecoratorType<BranchDecorator>> BRANCH = 
    register("branch", BranchDecorator.TYPE);
Supplier<TreeDecoratorType<PlaceOnGroundDecorator>> PLACE_ON_GROUND = 
    register("place_on_ground", PlaceOnGroundDecorator.TYPE);
Supplier<TreeDecoratorType<WillowTrunkDecorator>> WILLOW = 
    register("willow", WillowTrunkDecorator.TYPE);

Branch decorator

Adds decorative branch blocks to tree trunks:

BranchDecorator.java:21-25

public static final MapCodec<BranchDecorator> CODEC = RecordCodecBuilder.<BranchDecorator>mapCodec(i -> i.group(
    Codec.floatRange(0, 1).fieldOf("probability").forGetter(d -> d.probability),
    BuiltInRegistries.BLOCK.byNameCodec().fieldOf("block").forGetter(d -> d.block),
    Codec.intRange(0, 16).fieldOf("required_empty_blocks").forGetter(d -> d.requiredEmptyBlocks)
).apply(i, BranchDecorator::new)).validate(BranchDecorator::validate);

BranchDecorator

class

Decorator that places branch blocks on tree logs

Show constructor

Constructor

public BranchDecorator(
    float probability,
    Block block,
    int requiredEmptyBlocks
)

Show parameters

probability

float

required

Chance to place a branch at each valid position (0.0-1.0)

block

Block

required

The branch block to place (must be instance of BranchBlock)

requiredEmptyBlocks

int

required

Number of empty blocks required below branch position (0-16)

Branch placement logic

BranchDecorator.java:52-60

@Override
public void place(Context context) {
    RandomSource random = context.random();
    for (BlockPos logsPos : RUUtils.shuffledCopy(context.logs(), random)) {
        Direction direction = RUUtils.getRandom(HORIZONTAL_DIRECTIONS, random);
        BlockPos placementPos = logsPos.relative(direction);
        if (!(random.nextFloat() <= this.probability) || !hasRequiredEmptyBlocks(context, placementPos)) continue;
        context.setBlock(placementPos, this.block.defaultBlockState().setValue(BranchBlock.FACING, direction));
    }
}

Iterate logs

Loop through all log positions in random order

Choose direction

Randomly select a horizontal direction (North, East, South, or West)

Check probability

Roll against the configured probability

Validate space

Ensure required empty blocks exist below placement position

Place branch

Set the branch block with appropriate facing direction

Validation

The branch decorator validates that the block is a proper BranchBlock:

Decorator validation

private static DataResult<BranchDecorator> validate(BranchDecorator decorator) {
    if (decorator.block instanceof BranchBlock) {
        return DataResult.success(decorator);
    }
    return DataResult.error(() -> 
        "Block must be instance of BranchBlock, got " + decorator.block.getClass().getName()
    );
}

Feature types

The RUFeatureTypes interface registers custom world features including trees, rocks, and special structures.

Tree features

Tree feature registration examples

Supplier<Feature<RuTreeConfiguration>> ASPEN_TREE = 
    register("aspen_tree", new AspenTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> CYPRESS_TREE = 
    register("cypress_tree", new CypressTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> MAPLE_TREE = 
    register("maple_tree", new MapleTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> REDWOOD_TREE = 
    register("redwood_tree", new RedwoodTreeFeature(RuTreeConfiguration.CODEC));

Mega tree features

Large tree variants for impressive structures:

Mega tree features

Supplier<Feature<RuTreeConfiguration>> MEGA_BAOBAB_TREE = 
    register("mega_baobab_tree", new MegaBaobabTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> ULTRA_BAOBAB_TREE = 
    register("ultra_baobab_tree", new UltraBaobabTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> SUPER_REDWOOD_TREE = 
    register("super_redwood_tree", new SuperRedwoodTreeFeature(RuTreeConfiguration.CODEC));
Supplier<Feature<RuTreeConfiguration>> ULTRA_REDWOOD_TREE = 
    register("ultra_redwood_tree", new UltraRedwoodTreeFeature(RuTreeConfiguration.CODEC));

Bioshroom features

Giant mushroom structures for cave biomes:

Bioshroom features

Supplier<Feature<GiantBioshroomConfiguration>> GIANT_BLUE_BIOSHROOM = 
    register("giant_blue_bioshroom", new GiantBlueBioshroomFeature(GiantBioshroomConfiguration.CODEC));
Supplier<Feature<GiantBioshroomConfiguration>> GIANT_GREEN_BIOSHROOM = 
    register("giant_green_bioshroom", new GiantGreenBioshroomFeature(GiantBioshroomConfiguration.CODEC));
Supplier<Feature<GiantBioshroomConfiguration>> GIANT_PINK_BIOSHROOM = 
    register("giant_pink_bioshroom", new GiantPinkBioshroomFeature(GiantBioshroomConfiguration.CODEC));
Supplier<Feature<GiantBioshroomConfiguration>> GIANT_YELLOW_BIOSHROOM = 
    register("giant_yellow_bioshroom", new GiantYellowBioshroomFeature(GiantBioshroomConfiguration.CODEC));

Decorative features

Vegetation and decoration

Supplier<Feature<ShrubConfiguration>> SHRUB = 
    register("shrub", new ShrubFeature(ShrubConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> GIANT_LILY = 
    register("giant_lily", new GiantLilyPadFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> ICICLE_UP = 
    register("icicle_up", new FloorIcicleFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<MultifaceGrowthConfiguration>> AIR_MULTIFACE_GROWTH = 
    register("air_multiface_growth", new AirMultifaceGrowthFeature(MultifaceGrowthConfiguration.CODEC));

Geological features

Rock and terrain features

Supplier<Feature<NoneFeatureConfiguration>> MEADOW_ROCK = 
    register("meadow_rock", new MeadowRockFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> ROCK = 
    register("rock", new RockFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> ROCK_PILLAR = 
    register("rock_pillar", new RockPillarFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<SeaRockConfiguration>> OCEAN_ROCK = 
    register("ocean_rock", new SeaRockFeature(SeaRockConfiguration.CODEC));
Supplier<Feature<ColumnFeatureConfiguration>> BASALT_BLOB = 
    register("basalt_blob", new BasaltBlobFeature(ColumnFeatureConfiguration.CODEC));

Special features

Unique world features

Supplier<Feature<PointedRedstoneConfiguration>> POINTED_REDSTONE = 
    register("pointed_redstone", new PointedRedstoneFeature(PointedRedstoneConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> HANGING_PRISMARITE = 
    register("hanging_prismarite", new HangingPrismariteFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<NoneFeatureConfiguration>> ASH_VENT = 
    register("scorch_vent", new AshVentFeature(NoneFeatureConfiguration.CODEC));
Supplier<Feature<VegetationPatchConfiguration>> OVERWORLD_LAVA_DELTA = 
    register("overworld_lava_delta", new LavaDeltaFeature(VegetationPatchConfiguration.CODEC));

Usage in datapacks

Using custom foliage placers

Sakura foliage placer in JSON

{
  "type": "regions_unexplored:sakura",
  "radius": 2,
  "offset": 0,
  "height": {
    "type": "minecraft:uniform",
    "min_inclusive": 4,
    "max_inclusive": 8
  },
  "flower_decoration_chance": 0.3
}

Using tree decorators

Branch decorator in JSON

{
  "type": "regions_unexplored:branch",
  "probability": 0.4,
  "block": "regions_unexplored:maple_branch",
  "required_empty_blocks": 3
}

Complete tree configuration

Maple tree with branch decorator

{
  "type": "regions_unexplored:maple_tree",
  "trunk_placer": {
    "type": "minecraft:straight_trunk_placer",
    "base_height": 5,
    "height_rand_a": 2,
    "height_rand_b": 0
  },
  "foliage_placer": {
    "type": "minecraft:blob_foliage_placer",
    "radius": 2,
    "offset": 0,
    "height": 3
  },
  "decorators": [
    {
      "type": "regions_unexplored:branch",
      "probability": 0.3,
      "block": "regions_unexplored:maple_branch",
      "required_empty_blocks": 2
    }
  ],
  "trunk_provider": {
    "type": "minecraft:simple_state_provider",
    "state": {
      "Name": "regions_unexplored:maple_log"
    }
  },
  "foliage_provider": {
    "type": "minecraft:simple_state_provider",
    "state": {
      "Name": "regions_unexplored:maple_leaves"
    }
  }
}

Registration pattern

All world generation components follow this registration pattern:

Generic registration

private static <T extends Type> Supplier<T> register(String name, T instance) {
    Registrar.register(BuiltInRegistries.REGISTRY, name, () -> instance);
    return () -> instance;
}

Features, foliage placers, and decorators can be referenced in configured features and placed features for use in biomes.

Development

API Reference

Overview

Foliage placers

Registered foliage placers

Sakura foliage placer

Foliage placement logic

Willow foliage placer

Tree decorators

Registered decorators

Branch decorator

Branch placement logic

Validation

Feature types

Tree features

Mega tree features

Bioshroom features

Decorative features

Geological features

Special features

Usage in datapacks

Using custom foliage placers

Using tree decorators

Complete tree configuration

Registration pattern

Build docs developers (and LLMs) love

Development

API Reference

​Overview

​Foliage placers

​Registered foliage placers

​Sakura foliage placer

​Foliage placement logic

​Willow foliage placer

​Tree decorators

​Registered decorators

​Branch decorator

​Branch placement logic

​Validation

​Feature types

​Tree features

​Mega tree features

​Bioshroom features

​Decorative features

​Geological features

​Special features

​Usage in datapacks

​Using custom foliage placers

​Using tree decorators

​Complete tree configuration

​Registration pattern

Build docs developers (and LLMs) love

Overview

Foliage placers

Registered foliage placers

Sakura foliage placer

Foliage placement logic

Willow foliage placer

Tree decorators

Registered decorators

Branch decorator

Branch placement logic

Validation

Feature types

Tree features

Mega tree features

Bioshroom features

Decorative features

Geological features

Special features

Usage in datapacks

Using custom foliage placers

Using tree decorators

Complete tree configuration

Registration pattern