# Material distribution

Each active direct item or tag mapping has one material-distribution row.

Material-distribution rows assign NTM material quantities to items or item tags. The Crucible melts a matching item into these quantities[since NTM 1.0.1: ; it does not melt an item with changed components, except foundry scrap]. The ICF Fuel Pellet Maker uses an item as solid fuel when its materials resolve to exactly 72 units of one of `lithium`, `beryllium`, `boron`, `graphite`, `sodium` or `calcium`.

## Fields

| Field | Meaning and default | Range |
| - | - | - |
| `type` | Selects the `hbm:material_distribution` recipe format. | |
| `materials` | Material stacks assigned to the target. | |
| `materials.material` | NTM material name. | |
| `materials.amount` | Quantity in NTM material units. | `i32` |
| `targets` | Item ID, item tag, or nonempty ID list receiving this material mapping. Each item and tag may be targeted by one row; a duplicate fails data loading. | |

An item's materials come from one tag row matching one of its tags, or else from the NTM material shape tag of a melting material, such as `#c:ingots/iron`. A row targeting the item adds its materials to that result. An ingot is 72 material units, a nugget 8, and a storage block 648.

## Example

Source path: `data/hbm/recipe/material_distribution/tag_c_stones.json`

```json
{
  "type": "hbm:material_distribution",
  "materials": [
    {
      "amount": 648,
      "material": "stone"
    }
  ],
  "targets": "#c:stones"
}
```