Block column feature

The block_column feature allows you to add a column of blocks (e.g. sugar cane or cacti) to the world.

Configuration

The following configuration options are available:

Option	Type	Description
`layers`	An array of `Layers`. See below for more information	Defines which block states should be used at specific heights.
`direction`	`north`, `east`, `south`, `west`, `up` or `down`	Determines the direction of the column.
`allowed_placement`	A BlockPredicate	A predicate that has to match every block in the column before the block is placed.
`prioritize_tip`	A `boolean`	When set to `true`, all underlying block will be removed if the current block doesn't match the provided BlockPredicate

In code, the BlockColumnConfiguration class is used to configure the feature.

Layer

Layers have 2 options: height, an IntProvider that determines the height of this layer, and block, a BlockStateProvider that determines the block state to use for this layer.

Examples

As an example, here's the configured feature used to place cacti in the desert.
Please note that Minecraft uses the random_patch feature to actually spread cacti and sugar cane.

Cactus

KotlinJson

ConfiguredFeatures.kt

@OptIn(ExperimentalWorldGen::class)
@Init(stage = InitStage.POST_PACK_PRE_WORLD)
object ConfiguredFeatures : FeatureRegistry by ExampleAddon.registry {

    val CACTUS = registerConfiguredFeature(
        "cactus",
        Feature.BLOCK_COLUMN,
        BlockColumnConfiguration(
            listOf(BlockColumnConfiguration.Layer(BiasedToBottomInt.of(1, 3), SimpleStateProvider.simple(Blocks.CACTUS))), The cactus only has a single layer of the cactus block which can be 1, 2 or 3 blocks high, biased towards a shorter height.

            Direction.UP, The cactus grows upwards.

            BlockPredicate.matchesBlocks(Blocks.AIR), Only place the cactus if the block above is air.

            false Only the top of the cactus will be cut off if the block above is not air.

        )
    )

}

configured_feature/cactus.json

{
  "type": "minecraft:block_column",
  "config": {
    "direction": "up", The cactus grows upwards.

    "allowed_placement": {
      "type": "minecraft:matching_blocks",
      "blocks": "minecraft:air" Only place the cactus if the block above is air.

    },
    "prioritize_tip": false, Only the top of the cactus will be cut off if the block above is not air.

    "layers": [
      { Since the cactus only needs the normal cactus block, we only need one layer.

        "height": { The cactus can be 1, 2 or 3 blocks high, biased towards a shorter height.

          "type": "minecraft:biased_to_bottom",
          "value": {
            "max_inclusive": 3,
            "min_inclusive": 1
          }
        },
        "provider": {
          "type": "minecraft:simple_state_provider",
          "state": {
            "Name": "minecraft:cactus",
            "Properties": {
              "age": "0"
            }
          }
        }
      }
    ]
  }
}

Result

AloneNaturally generated

Example

Glow berry vines

Or, as another example, here's the configured and placed feature for glow berries/cave vines.

KotlinJson

ConfiguredFeatures.kt

@OptIn(ExperimentalWorldGen::class)
@Init(stage = InitStage.POST_PACK_PRE_WORLD)
object ConfiguredFeatures : FeatureRegistry by ExampleAddon.registry {

    val CAVE_VINE: ConfiguredFeature<BlockColumnConfiguration, Feature<BlockColumnConfiguration>>

    init {
        val upperStateProvider = WeightedStateProvider( Each block of the upper layer of the vine can either be a normal or a vine with berries (biased towards normal).

            SimpleWeightedRandomList.builder<BlockState>()
                .add(Blocks.CAVE_VINES_PLANT.defaultBlockState(), 4)
                .add(Blocks.CAVE_VINES_PLANT.defaultBlockState().setValue(CaveVines.BERRIES, true), 1)
        )

        val bottomStateProvider = RandomizedIntStateProvider(WeightedStateProvider( The bottom layer of the vine can either be a normal or a vine with berries (biased towards normal), and the age of the vine is randomized between 23 and 25.

            SimpleWeightedRandomList.builder<BlockState>()
                .add(Blocks.CAVE_VINES.defaultBlockState(), 4)
                .add(Blocks.CAVE_VINES.defaultBlockState().setValue(CaveVines.BERRIES, true), 1)
        ), CaveVinesBlock.AGE, UniformInt.of(23, 25))

        val config = BlockColumnConfiguration(
            listOf( The vine has two layers, the upper layer (upperStateProvider) and the bottom layer (bottomStateProvider).

                BlockColumnConfiguration.Layer(
                    WeightedListInt( The upper layer can be 0 to 19 blocks high, biased towards a medium height.

                        SimpleWeightedRandomList.builder<IntProvider>()
                            .add(UniformInt.of(0, 19), 2)
                            .add(UniformInt.of(0, 2), 3)
                            .add(UniformInt.of(0, 6), 10)
                            .build()
                    ),
                    upperStateProvider The upper layer can be either a normal or a vine with berries (biased towards normal).

                ),
                BlockColumnConfiguration.Layer(
                    ConstantInt.of(1), The bottom layer is always 1 block high.

                    bottomStateProvider The bottom layer can be either a normal or a vine with berries (biased towards normal), and the age of the vine is randomized between 23 and 25.

                )
            ),
            Direction.DOWN, The vine grows downwards.

            BlockPredicate.ONLY_IN_AIR_PREDICATE, Only place the vine if the block below is air.

            true If the predicate fails, the entire vine will be removed.

        )

        CAVE_VINE = registerConfiguredFeature("cave_vine", Feature.BLOCK_COLUMN, config)
    }

}

PlacedFeatures.kt

@OptIn(ExperimentalWorldGen::class)
@Init(stage = InitStage.POST_PACK_PRE_WORLD)
object PlacedFeatures: FeatureRegistry by ExampleAddon.registry {

    val CAVE_VINE = placedFeature("cave_vine", ConfiguredFeatures.CAVE_VINE)
        .count(188) 188 tries per chunk.

        .inSquareSpread() Spread the locations in a square.

        .heightRangeUniform(VerticalAnchor.BOTTOM, VerticalAnchor.absolute(256)) Only place the vines in the y-range of bottom to 256.

        .environmentScan( Search for the first block that has a solid face downwards (max 12 blocks away).

            Direction.UP,
            BlockPredicate.hasSturdyFace(Direction.DOWN),
            BlockPredicate.ONLY_IN_AIR_PREDICATE,
            12
        )
        .randomVerticalOffset(-1) Offset the location by  $(0, - 1, 0)$ .

        .biomeFilter() Only place the vines if the current biome has cave vines.

        .register()

}

configured_feature/cave_vine.json

{
  "type": "minecraft:block_column",
  "config": {
    "direction": "down", The vines grow downwards.

    "allowed_placement": {
      "type": "minecraft:matching_blocks",
      "blocks": "minecraft:air" Only place the vines if the block below is air.

    },
    "prioritize_tip": true, Remove all vines if the block below is not air.

    "layers": [
      { Place multiple cave vine plants (glow berries) at the top and always add a single cave vine at the bottom.

        "height": {
          "type": "minecraft:weighted_list",
          "distribution": [
            {
              "data": {
                "type": "minecraft:uniform",
                "value": {
                  "max_inclusive": 19,
                  "min_inclusive": 0
                }
              },
              "weight": 2
            },
            {
              "data": {
                "type": "minecraft:uniform",
                "value": {
                  "max_inclusive": 2,
                  "min_inclusive": 0
                }
              },
              "weight": 3
            },
            {
              "data": {
                "type": "minecraft:uniform",
                "value": {
                  "max_inclusive": 6,
                  "min_inclusive": 0
                }
              },
              "weight": 10
            }
          ]
        },
        "provider": {
          "type": "minecraft:weighted_state_provider",
          "entries": [
            {
              "data": {
                "Name": "minecraft:cave_vines_plant",
                "Properties": {
                  "berries": "false"
                }
              },
              "weight": 4
            },
            {
              "data": {
                "Name": "minecraft:cave_vines_plant",
                "Properties": {
                  "berries": "true"
                }
              },
              "weight": 1
            }
          ]
        }
      },
      {
        "height": 1,
        "provider": {
          "type": "minecraft:randomized_int_state_provider",
          "property": "age",
          "source": {
            "type": "minecraft:weighted_state_provider",
            "entries": [
              {
                "data": {
                  "Name": "minecraft:cave_vines",
                  "Properties": {
                    "age": "0",
                    "berries": "false"
                  }
                },
                "weight": 4
              },
              {
                "data": {
                  "Name": "minecraft:cave_vines",
                  "Properties": {
                    "age": "0",
                    "berries": "true"
                  }
                },
                "weight": 1
              }
            ]
          },
          "values": {
            "type": "minecraft:uniform",
            "value": {
              "max_inclusive": 25,
              "min_inclusive": 23
            }
          }
        }
      }
    ]
  }
}

placed_feature/cave_vines.json

{
  "feature": "minecraft:cave_vine",
  "placement": [
    {
      "type": "minecraft:count",
      "count": 188 188 tries per chunk.

    },
    {
      "type": "minecraft:in_square" Spread the locations in a square.

    },
    {
      "type": "minecraft:height_range", Only place the vines in the y-range of bottom to 256.

      "height": {
        "type": "minecraft:uniform",
        "max_inclusive": {
          "absolute": 256
        },
        "min_inclusive": {
          "above_bottom": 0
        }
      }
    },
    {
      "type": "minecraft:environment_scan", Search for the first block that has a solid face downwards (max 12 blocks away).

      "allowed_search_condition": {
        "type": "minecraft:matching_blocks",
        "blocks": "minecraft:air"
      },
      "direction_of_search": "up",
      "max_steps": 12,
      "target_condition": {
        "type": "minecraft:has_sturdy_face",
        "direction": "down"
      }
    },
    {
      "type": "minecraft:random_offset", Offset the location by  $(0, - 1, 0)$ .

      "xz_spread": 0,
      "y_spread": -1
    },
    {
      "type": "minecraft:biome" Only place the vines if the current biome has cave vines.

    }
  ]
}

Result

AloneNaturally generated

Example