# hbm:procedural

Generates a procedural NTM structure at suitable surface terrain.

Vanilla structure settings follow the [Minecraft data pack format](https://minecraft.wiki/w/Data_pack).

## Fields

| Field | Meaning and default |
| - | - |
| `type` | Selects the structure implementation. |
| `biomes` | Vanilla biome set eligible for placement. |
| `spawn_overrides` | Vanilla mob-spawn overrides inside the structure. |
| `step` | Vanilla generation step for the structure. |
| `terrain_adaptation` | Vanilla terrain adaptation around the structure. |

> **since NTM 1.0.1**
>
> When its generation step runs, the piece moves to the light-blocking surface height and generates only over grass, dirt, coarse dirt, podzol, sand, red sand or `#minecraft:base_stone_overworld`, directly or beneath snow or a plant.

## Example

Source path: `data/hbm/worldgen/structure/antenna.json`

*NTM 1.0.0:*

```json
{
  "type": "hbm:procedural",
  "biomes": [
    "minecraft:badlands",
    "minecraft:beach",
    "minecraft:birch_forest",
    "minecraft:cold_ocean",
    "minecraft:dark_forest",
    "minecraft:deep_cold_ocean",
    "minecraft:deep_dark",
    "minecraft:deep_frozen_ocean",
    "minecraft:deep_lukewarm_ocean",
    "minecraft:deep_ocean",
    "minecraft:desert",
    "minecraft:dripstone_caves",
    "minecraft:eroded_badlands",
    "minecraft:flower_forest",
    "minecraft:forest",
    "minecraft:lukewarm_ocean",
    "minecraft:lush_caves",
    "minecraft:ocean",
    "minecraft:old_growth_birch_forest",
    "minecraft:pale_garden",
    "minecraft:plains",
    "minecraft:river",
    "minecraft:savanna",
    "minecraft:savanna_plateau",
    "minecraft:stony_peaks",
    "minecraft:sulfur_caves",
    "minecraft:sunflower_plains",
    "minecraft:warm_ocean",
    "minecraft:windswept_savanna",
    "minecraft:wooded_badlands"
  ],
  "spawn_overrides": {},
  "step": "strongholds",
  "terrain_adaptation": "beard_thin"
}
```

*NTM 1.0.1–1.0.4:*

```json
{
  "type": "hbm:procedural",
  "biomes": [
    "minecraft:badlands",
    "minecraft:beach",
    "minecraft:birch_forest",
    "minecraft:cold_ocean",
    "minecraft:dark_forest",
    "minecraft:deep_cold_ocean",
    "minecraft:deep_dark",
    "minecraft:deep_frozen_ocean",
    "minecraft:deep_lukewarm_ocean",
    "minecraft:deep_ocean",
    "minecraft:desert",
    "minecraft:dripstone_caves",
    "minecraft:eroded_badlands",
    "minecraft:flower_forest",
    "minecraft:forest",
    "minecraft:lukewarm_ocean",
    "minecraft:lush_caves",
    "minecraft:ocean",
    "minecraft:old_growth_birch_forest",
    "minecraft:pale_garden",
    "minecraft:plains",
    "minecraft:river",
    "minecraft:savanna",
    "minecraft:savanna_plateau",
    "minecraft:stony_peaks",
    "minecraft:sulfur_caves",
    "minecraft:sunflower_plains",
    "minecraft:warm_ocean",
    "minecraft:windswept_savanna",
    "minecraft:wooded_badlands"
  ],
  "spawn_overrides": {},
  "step": "top_layer_modification"
}
```