Custom blends can be added via datapacks. Each custom blend is defined as a JSON file located at:

data/<namespace>/biomeblends/blend_type/<blend_name>.json

Blend Actions

The action field defines what happens when a blend is applied. Only one action may be defined per blend.

Set Biome Action

Sets a specific biome in the blend area.

{
  "action": {
    "type": "biomeblends:set_biome",
    "target_biome": "minecraft:plains"
  }
}

• target_biome: ID of the biome to apply.

Set Namespace Action

Replaces the namespace of each biome in the blend area, attempting to find a matching biome in the new namespace. If there is no matching biome, it will be changed into the fallback biome (if specified).

While this action type doesn't normally have a use, it can be extremely useful for modpack creators. The blend created in the example below will attempt to change any biome, eg. wasteland:forest to minecraft:forest. Additionally, if there is no matching minecraft biome, it will be changed into minecraft:plains.

{
  "action": {
    "type": "biomeblends:set_namespace",
    "target_namespace": "minecraft",
    "fallback_biome": "minecraft:plains"
  }
}

• target_namespace: New namespace to apply to biome IDs.
• fallback_biome: If specified, this biome will be created if there is no matching biome in the target namespace (optional).

Radius

The horizontal_radius and vertical_radius control the region that is affected by the blend. The area is always centered on the block where the blend is used, but since Minecraft stores biomes in 4x4x4 cubes, it may not always be exact. vertical_radius can be set to -1, which will cause it to affect the entire vertical column.

By default the horizontal_radius and vertical_radius is set to 4.

Conditions

Conditions can be used to stop your blends from interacting with certain mods, dimensions or biomes.

Dimension Blacklist

Prevents this blend from being applied in specified dimensions. If negate is set to true, it will act as a whitelist.

  "dimension_blacklist": {
    "values": ["minecraft:the_nether", "custom:another_dimension"],
    "negate": false
  }

Biome Blacklist

Prevents this blend from being applied inside specified biomes. If negate is set to true, it will act as a whitelist. Keep in mind that a blend will still be applied if there is any region that meets this condition.

  "biome_blacklist": {
    "values": ["minecraft:desert", "minecraft:swamp"],
    "negate": false
  }

Namespace Blacklist

Excludes blends from applying to biomes within certain namespaces. If negate is set to true, it will act as a whitelist. Keep in mind that a blend will still be applied if there is any region that meets this condition.

  "namespace_blacklist": {
    "values": ["minecraft", "wasteland"],
    "negate": false
  }

A practical tool for keeping your blend from interfering with biomes from a specific mod or datapack.

Blend Color

The color field is used to apply a color overlay to the blend's texture. If not set, there is no color applied.

Keep in mind that it only accepts colors in decimal format, which means you will need to convert a number from hexadecimal to decimal, eg. #FF0000 to 16711680.

Use Remainder

use_remainder is an item that can be given to the player when the blend gets consumed.

  "use_remainder": {
    "id": "minecraft:glass_bottle"
  }

Sound

The default use sound can be changed using the sound option.

  "sound": {
    "sound_id": "minecraft:block.anvil.land"
  }

Particles

The default type of particles that is applied on use can be changed with particle_type.

  "particle_type": {
    "type": "minecraft:block",
    "block_state": "minecraft:anvil"
  }

Full Example

The following example creates a blend that sets the biome to bamboo jungle, uses anvil sounds and particles and spawns a glass bottle when used. It has a horizontal distance of 10 and an infinite vertical radius, meaning it will affect the entire column.

{
  "action": {
    "type": "biomeblends:set_biome",
    "target_biome": "minecraft:bamboo_jungle"
  },
  "color": 11705,
  "use_remainder": {
    "id": "minecraft:glass_bottle"
  },
  "sound": {
    "sound_id": "minecraft:block.anvil.land"
  },
  "particle_type": {
    "type": "minecraft:block",
    "block_state": "minecraft:anvil"
  },
  "vertical_radius": -1,
  "horizontal_radius": 10
}