# Environment Attributes > Data-driven visual, audio and gameplay rules for Minecraft biomes and dimensions - fog, sky, music, mob behavior - with Kore's DSL. Updated 2026-10-26. Canonical: https://kore.ayfri.com/docs/data-driven/worldgen/environment-attributes Environment attributes are the data-driven knobs controlling how a place in the world looks, sounds and behaves. Each one covers a single effect: `visual/sky_color` is the color of the sky, `gameplay/water_evaporates` decides whether a bucket can place water. Both [biomes](https://kore.ayfri.com/docs/data-driven/worldgen/biomes.md) and [dimension types](https://kore.ayfri.com/docs/data-driven/worldgen/dimensions.md) declare them in an `attributes { }` block, and both use the exact same builders. Everything the removed `effects`, `natural`, `ultrawarm`, `piglin_safe`, `bed_works` and `has_raids` fields used to control lives here. ```kotlin attributes { skyColor(0x78A7FF) fogEndDistance(192.0f) waterEvaporates(true) } ``` References: [Biome definition](https://minecraft.wiki/w/Biome_definition), [Dimension type](https://minecraft.wiki/w/Dimension_type) --- ## Priority, Modifiers, Interpolation A dimension type provides the base value for the whole world, a biome overrides it locally. Setting `sky_color` to green on the dimension and to red on the plains biome gives a red sky in the plains, green everywhere else. By default a value **overrides** whatever the lower-priority source provided. Pass a modifier as the second argument to combine with it instead, and the JSON expands from a bare value to `{ "argument": ..., "modifier": ... }`: ```kotlin attributes { skyColor(0x78A7FF) // Override, the default. fogEndDistance(0.85f, EnvironmentAttributeModifier.MULTIPLY) // 85% of the dimension value. } ``` Which modifiers apply depends on the value type of the attribute: | Value type | Available modifiers | |------------------------|-------------------------------------------------------------------------| | **Boolean** | `OVERRIDE`, `AND`, `NAND`, `OR`, `NOR`, `XOR`, `XNOR` | | **Float** | `OVERRIDE`, `ADD`, `SUBTRACT`, `MULTIPLY`, `MINIMUM`, `MAXIMUM` | | **Color** | `OVERRIDE`, `ADD`, `SUBTRACT`, `MULTIPLY`, `ALPHA_BLEND`, `BlendToGray` | | **List** | `OVERRIDE`, `APPEND` | | **Natural mob spawns** | `OVERRIDE`, `OVERLAY` | | **Object** | `OVERRIDE` only | `ALPHA_BLEND` takes an ARGB argument and does traditional alpha blending; an alpha of `1` behaves as an override. `BlendToGray` is the one modifier carrying data of its own: ```kotlin fogColor(rgb(255, 170, 0), EnvironmentAttributeModifier.BlendToGray(brightness = 0.5f, factor = 0.8f)) ``` ```json { "argument": 16755200, "modifier": { "type": "blend_to_gray", "brightness": 0.5, "factor": 0.8 } } ``` Attributes marked **interpolated** in the tables below fade smoothly as the player crosses a biome border, sampling the biomes within 8 blocks of the camera. The others snap to the biome at the exact position. --- ## Visual | Builder | Value | Default | Interp. | Resolved at | Controls | |----------------------------------|----------------|-----------------|---------|------------------|------------------------------------------------------------------| | `ambientLightColor(color)` | RGB color | `#000000` | Yes | Camera | Tint of the scene's ambient illumination. | | `ambientParticles(...)` | Particle list | `[]` | No | Camera | Particles randomly spawning around the camera. | | `blockLightTint(color)` | RGB color | `#000000` | Yes | Camera | Tint applied to block-emitted light. | | `cloudColor(argb)` | ARGB color | `#00000000` | Yes | Camera | Color of the clouds. | | `cloudFogEndDistance(float)` | Float, >= 0 | `1024.0` | Yes | Camera | Distance in blocks at which cloud fog ends. | | `cloudHeight(float)` | Float | `192.33` | Yes | Camera | Height all clouds are drawn at. | | `defaultDripstoneParticle(...)` | Particle | dripstone water | No | Dripstone block | Particle dripped when no fluid sits above the dripstone. | | `fogColor(color)` | RGB color | `#000000` | Yes | Camera | Fog color out of water. Time, weather and potions affect it too. | | `fogEndDistance(float)` | Float, >= 0 | `1024.0` | Yes | Camera | Distance in blocks at which fog ends. | | `fogStartDistance(float)` | Float, >= 0 | `0.0` | Yes | Camera | Distance in blocks at which fog starts. | | `moonAngle(float)` | Float, degrees | `0.0` | Yes | Overworld camera | Angle of the moon. | | `moonPhase(texture)` | Moon phase | `full_moon` | No | Overworld camera | Which moon phase texture is drawn. | | `nightVisionColor(color)` | RGB color | `#000000` | Yes | Camera | Tint applied under the Night Vision effect. | | `skyColor(color)` | RGB color | `#000000` | Yes | Camera | Sky color, Overworld sky only. Time and weather affect it too. | | `skyFogEndDistance(float)` | Float, >= 0 | `512.0` | Yes | Camera | Distance in blocks at which sky fog ends. | | `skyLightColor(color)` | RGB color | - | Yes | Camera | Tint applied to sky light. | | `skyLightFactor(float)` | Float | - | Yes | Camera | How strongly sky light contributes to the scene. | | `starAngle(float)` | Float, degrees | - | Yes | Overworld camera | Rotation of the star field. | | `starBrightness(float)` | Float | - | Yes | Overworld camera | Brightness of the stars. | | `sunAngle(float)` | Float, degrees | - | Yes | Overworld camera | Angle of the sun. | | `sunriseSunsetColor(argb)` | ARGB color | - | Yes | Overworld camera | Color of the sunrise and sunset glow. | | `waterFogColor(color)` | RGB color | `#050533` | Yes | Camera | Fog color while submerged in water. | | `waterFogEndDistance(float)` | Float | `-8.0` | Yes | Camera | Distance in blocks at which underwater fog ends. | | `waterFogStartDistance(float)` | Float | `0.0` | Yes | Camera | Distance in blocks at which underwater fog starts. | ```kotlin attributes { skyColor(Color.RED) fogColor(rgb(255, 170, 0), EnvironmentAttributeModifier.ADD) cloudColor(ARGB(255, 128, 64, 32)) blockLightTint(rgb(255, 180, 80), EnvironmentAttributeModifier.MULTIPLY) moonPhase(Textures.Environment.Celestial.Moon.FULL_MOON) defaultDripstoneParticle(simpleParticle(Particles.DRIPPING_LAVA)) } ``` Color builders take an `Int` hex literal, a `Color`, or an `rgb(r, g, b)` / `ARGB(a, r, g, b)` call. See [Colors](https://kore.ayfri.com/docs/concepts/colors.md). ### Ambient Particles `ambientParticles` takes one `particle(options, probability)` per entry in its block, pairing [particle options](https://kore.ayfri.com/docs/commands/commands.md#particle-options) with the chance to spawn them in an empty space. `simpleParticle(...)` builds a particle without options, and factories such as `dustParticle` build the ones that have some. ```kotlin attributes { ambientParticles { particle(simpleParticle(Particles.ASH), probability = 0.01f) particle(simpleParticle(Particles.WHITE_ASH), probability = 0.005f) particle(dustParticle(Color.RED), probability = 0.1f) } } ``` The dust entry is written with its options inline, its color as a packed int: ```json { "particle": { "type": "minecraft:dust", "color": 16733525, "scale": 1.0 }, "probability": 0.1 } ``` With `EnvironmentAttributeModifier.APPEND`, the particles are added after the ones of the lower-priority source, a biome keeping the particles of its dimension for instance, instead of replacing them. ```kotlin attributes { ambientParticles(EnvironmentAttributeModifier.APPEND) { particle(simpleParticle(Particles.WHITE_ASH), 0.1f) } } ``` `defaultDripstoneParticle` takes the same particle options, and writes them as the attribute value itself: ```kotlin attributes { defaultDripstoneParticle(simpleParticle(Particles.DRIPPING_DRIPSTONE_WATER)) } ``` ```json "minecraft:visual/default_dripstone_particle": { "type": "minecraft:dripping_dripstone_water" } ``` --- ## Audio | Builder | Value | Default | Interp. | Resolved at | Controls | |----------------------------|-----------------|---------|---------|--------------|------------------------------------------------------| | `ambientSounds(...)` | Object | `{}` | No | Camera | Looping, mood and random ambient sounds. | | `backgroundMusic(...)` | Object | `{}` | No | Camera | Which background music plays, and how often. | | `fireflyBushSounds(bool)` | Boolean | `false` | No | Firefly bush | Whether firefly bushes make noise. | | `musicVolume(float)` | Float, 0 to 1 | `1.0` | No | Camera | Target volume music fades to. | ### Ambient Sounds - `loop` - a sound continually looped. - `mood { }` - the cave-ambience style sound: `sound`, `tickDelay` (default `6000`), `blockSearchExtent` (default `8`), `offset` (default `2.0`). - `addition(sound, tickChance)` - a sound with a per-tick chance to play, repeatable. ```kotlin attributes { ambientSounds(loop = SoundEvents.Ambient.CAVE) { mood(sound = SoundEvents.Ambient.CAVE, tickDelay = 6000) addition(SoundEvents.Ambient.CAVE, 0.01f) } } ``` ### Background Music Three tracks, each taking a `sound`, a `minDelay`/`maxDelay` range in ticks, and an optional `replaceCurrentMusic`. `creative` and `underwater` override `default` in their respective situations. ```kotlin attributes { backgroundMusic { default(sound = SoundEvents.Music.GAME, minDelay = 12000, maxDelay = 24000) creative(sound = SoundEvents.Music.CREATIVE, minDelay = 100, maxDelay = 200) underwater(sound = SoundEvents.Music.UNDER_WATER, minDelay = 100, maxDelay = 200, replaceCurrentMusic = true) } } ``` --- ## Gameplay | Builder | Value | Default | Interp. | Resolved at | Controls | |----------------------------------|--------------------------|-------------|---------|--------------------|------------------------------------------------------------------| | `babyVillagerActivity(activity)` | Activity | `idle` | No | Villager | What baby villagers do. | | `bedRule(...)` | Object | `when_dark` | No | Bed head | Whether a bed lets you sleep, set spawn, or is destroyed. | | `beesStayInHive(bool)` | Boolean | `false` | No | Hive | Whether bees stay inside their hive. | | `canPillagerPatrolSpawn(bool)` | Boolean | `true` | No | Patrol spawn | Whether pillager patrols spawn. | | `canStartRaid(bool)` | Boolean | `true` | No | Raid start | Whether Raid Omen can start a raid. | | `catWakingUpGiftChance(float)` | Float | `0.0` | Yes | Cat | Chance for a cat to leave a waking-up gift. | | `creakingActive(bool)` | Boolean | `false` | No | Creaking | Whether the Creaking is active. | | `creatureWorldGenSpawnProbability(float)` | Float, 0 to 0.9999999 | `0.1` | No | Chunk generation | Chance per chunk for the initial creature spawn at world generation. | | `eyeblossomOpen(state)` | `TRUE`/`FALSE`/`DEFAULT` | `DEFAULT` | No | Eyeblossom | Whether eyeblossoms are open. | | `fastLava(bool)` | Boolean | `false` | No | Whole dimension | Lava spreading faster, further, and pushing harder. | | `increasedFireBurnout(bool)` | Boolean | `false` | No | Burning fire block | Whether fire blocks burn out faster. | | `monstersBurn(bool)` | Boolean | `false` | No | Mob | Whether monsters burn in sunlight. | | `naturalMobSpawns(...)` | Object | `{}` | No | Spawn position | The mobs spawned naturally and their spawn costs. | | `netherPortalSpawnsPiglin(bool)` | Boolean | `false` | No | Nether portal | Whether nether portal blocks spawn piglins. | | `piglinsZombify(bool)` | Boolean | `true` | No | Zombifying entity | Whether piglins and hoglins zombify. | | `respawnAnchorWorks(bool)` | Boolean | `false` | No | Respawn anchor | Whether a respawn anchor sets spawn instead of exploding. | | `skyLightLevel(float)` | Float, 0 to 15 | `15.0` | No | Whole dimension | Sky light level of the dimension. | | `snowGolemMelts(bool)` | Boolean | `false` | No | Snow golem | Whether snow golems take damage. | | `strawBedRule(...)` | Object | `when_dark` | No | Straw bed head | Whether a straw bed lets you sleep, set spawn, or is destroyed. | | `surfaceSlimeSpawnChance(float)` | Float | `0.0` | Yes | Spawn position | Chance for surface slimes to spawn. | | `turtleEggHatchChance(float)` | Float | `0.0` | Yes | Turtle egg | Chance for turtle eggs to hatch. | | `villagerActivity(activity)` | Activity | `idle` | No | Villager | What villagers do. | | `waterEvaporates(bool)` | Boolean | `false` | No | Interaction | Buckets failing, ice melting dry, sponges drying, dripstone dry. | `fastLava` and `skyLightLevel` resolve for the whole dimension and cannot be set on a biome. ```kotlin attributes { fastLava(true) waterEvaporates(true, EnvironmentAttributeModifier.OR) piglinsZombify(false) villagerActivity(Activities.WORK) eyeblossomOpen(EyeblossomOpenState.TRUE) } ``` ### Natural Mob Spawns `naturalMobSpawns` sets the mobs spawning naturally, one weighted list per mob category, and the spawn costs capping their density. It belongs in the attributes of a [biome](https://kore.ayfri.com/docs/data-driven/worldgen/biomes.md) or a dimension type, and `creatureWorldGenSpawnProbability` sets the chance per chunk of the initial creature spawn at world generation. `spawner(type, weight, minCount, maxCount)` writes a constant `count` when both are equal and a `uniform` one otherwise. Call `count` inside the block with a plain `Int` or another [int provider](https://kore.ayfri.com/docs/data-driven/worldgen/providers.md). A `spawnCost(type, energyBudget, charge)` makes a mob spend `charge` from a shared `energyBudget`, so a crowded area stops spawning it. ```kotlin attributes { creatureWorldGenSpawnProbability(0.07f) naturalMobSpawns { spawnsByCategory { ambient { spawner(EntityTypes.BAT, weight = 10, minCount = 8) } creature { spawner(EntityTypes.SHEEP, weight = 12, minCount = 4) spawner(EntityTypes.HORSE, weight = 5, minCount = 2, maxCount = 6) spawner(EntityTypes.DONKEY) { weight = 1 count(uniform(1, 3)) } } } spawnCosts { spawnCost(EntityTypes.ZOMBIE, energyBudget = 1.0f, charge = 0.5f) } } } ``` ```json { "minecraft:gameplay/creature_world_gen_spawn_probability": 0.07, "minecraft:gameplay/natural_mob_spawns": { "spawn_costs": { "minecraft:zombie": { "energy_budget": 1.0, "charge": 0.5 } }, "spawns_by_category": { "ambient": [{ "count": 8, "type": "minecraft:bat", "weight": 10 }], "creature": [ { "count": 4, "type": "minecraft:sheep", "weight": 12 }, { "count": { "type": "minecraft:uniform", "min_inclusive": 2, "max_inclusive": 6 }, "type": "minecraft:horse", "weight": 5 }, { "count": { "type": "minecraft:uniform", "min_inclusive": 1, "max_inclusive": 3 }, "type": "minecraft:donkey", "weight": 1 } ] } } } ``` By default the value overrides the one of the lower-priority source. With `EnvironmentAttributeModifier.OVERLAY`, the categories and spawn costs set here replace the matching ones and the others are kept, so a biome can change the monsters of its dimension and leave the creatures alone: ```kotlin attributes { naturalMobSpawns(EnvironmentAttributeModifier.OVERLAY) { spawnsByCategory { monster { spawner(EntityTypes.CREEPER, weight = 100, minCount = 4) } } } } ``` Structures replace these lists inside their bounding box through [spawn overrides](https://kore.ayfri.com/docs/data-driven/worldgen/structures.md). ### Bed Rule `canSleep` and `canSetSpawn` each take `BedSleepRule.ALWAYS`, `WHEN_DARK` or `NEVER`. `destroyOnUse` destroys the bed (it explodes) when it is used, `destroyOnLeave` destroys it when the player leaves it (both default to `false`), and `errorMessage` replaces the message shown when sleeping is refused. ```kotlin attributes { bedRule( canSleep = BedSleepRule.NEVER, canSetSpawn = BedSleepRule.NEVER, destroyOnUse = true, errorMessage = textComponent("The beds here do not like you."), ) } ``` `strawBedRule` takes the same arguments and applies to straw beds. ```kotlin attributes { strawBedRule(canSleep = BedSleepRule.ALWAYS, canSetSpawn = BedSleepRule.NEVER, destroyOnLeave = true) } ``` ## See Also - [Biomes](https://kore.ayfri.com/docs/data-driven/worldgen/biomes.md) - per-biome attribute overrides - [Colors](https://kore.ayfri.com/docs/concepts/colors.md) - the RGB and ARGB formats used by color attributes - [Dimensions](https://kore.ayfri.com/docs/data-driven/worldgen/dimensions.md) - dimension-wide base attributes - [Timelines](https://kore.ayfri.com/docs/data-driven/timelines.md) - animating attributes over time with keyframes and easing - [World Generation](https://kore.ayfri.com/docs/data-driven/worldgen.md) - overview of the worldgen system