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 and dimension types 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.

attributes {
	skyColor(0x78A7FF)
	fogEndDistance(192.0f)
	waterEvaporates(true)
}

References: Biome definition, 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": ... }:

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:

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:

fogColor(rgb(255, 170, 0), EnvironmentAttributeModifier.BlendToGray(brightness = 0.5f, factor = 0.8f))

{
	"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

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(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.

Ambient Particles

ambientParticles takes Particle entries as varargs or a list, each pairing a particle type with the chance to spawn it in an empty space. The entry(...) helper inside the block is the shortest form.

attributes {
	ambientParticles {
		entry(Particles.ASH, probability = 0.01f)
		entry(Particles.WHITE_ASH, probability = 0.005f)
	}
}

Audio

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.

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.

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

fastLava and skyLightLevel resolve for the whole dimension and cannot be set on a biome.

attributes {
	fastLava(true)
	waterEvaporates(true, EnvironmentAttributeModifier.OR)
	piglinsZombify(false)
	villagerActivity(Activities.WORK)
	eyeblossomOpen(EyeblossomOpenState.TRUE)
}

Bed Rule

canSleep and canSetSpawn each take BedSleepRule.ALWAYS, WHEN_DARK or NEVER. explodes makes the bed detonate on interaction, and errorMessage replaces the message shown when sleeping is refused.

attributes {
	bedRule(
		canSleep = BedSleepRule.NEVER,
		canSetSpawn = BedSleepRule.NEVER,
		explodes = true,
		errorMessage = textComponent("The beds here do not like you."),
	)
}

See Also

• Biomes - per-biome attribute overrides
• Colors - the RGB and ARGB formats used by color attributes
• Dimensions - dimension-wide base attributes
• Timelines - animating attributes over time with keyframes and easing
• World Generation - overview of the worldgen system