# hbmspace:cave

Caves with lava below a level.

Vanilla-shaped caves through `replaceable` blocks: air above `lava_level` and `lava` at and below it. An ellipsoid whose shell holds water is skipped. A cut column that passed a `top` block gives the `filler` block it exposes the biome's surface material. On 26.3, a `minecraft:noise` generator whose biomes list a Space carver runs its carving after the surface pass, with vanilla carvers of the same biomes; Space carvers work only in such generators.

## Fields

| Field | Meaning and default | Range |
| - | - | - |
| `probability` | Chance that a source chunk starts the carver. | `[0, 1]` |
| `y` | Vanilla height provider for start heights. | |
| `y_scale` | Vanilla float provider: vertical scale of rooms. | |
| `lava_level` | Vertical anchor at and below which cuts fill with the lava block. | |
| `replaceable` | Block ID, `#tag` or ID list: blocks the carver may cut. | |
| `horizontal_radius_multiplier` | Vanilla float provider. | |
| `vertical_radius_multiplier` | Vanilla float provider. | |
| `floor_level` | Vanilla float provider within `[-1, 1]`. | |
| `lava` | Fill at and below `lava_level`. | |
| `lava.id` | Registered block ID. | |
| `lava.properties` (Optional) | Block-state property names and string values. | |
| `top` | Block ID, `#tag` or ID list: surface blocks. | |
| `filler` | Block ID, `#tag` or ID list: blocks re-topped when exposed. | |

The top-level `type` selects this carver; the remaining fields belong beside it.

## Example

Source path: `data/hbmspace/worldgen/carver/mun/caves.json`

```json
{
  "type": "hbmspace:cave",
  "filler": "hbmspace:moon_rock",
  "floor_level": -0.7,
  "horizontal_radius_multiplier": 1.0,
  "lava": "minecraft:lava",
  "lava_level": {
    "absolute": 1
  },
  "probability": 0.14285715,
  "replaceable": [
    "hbmspace:moon_rock",
    "hbm:moon_turf"
  ],
  "top": "hbm:moon_turf",
  "vertical_radius_multiplier": 1.0,
  "y": {
    "type": "minecraft:biased_to_bottom",
    "inner": 8,
    "max_inclusive": {
      "absolute": 127
    },
    "min_inclusive": {
      "absolute": 0
    }
  },
  "y_scale": 0.5
}
```