# Rock Mill

Uses up to three item inputs, three output positions, one input fluid and one output fluid. Further output and fluid entries are ignored; a row with more item inputs than slots never matches. Fluid tanks resize to twice the recipe amount, at least 4,000 mB. When the recipe icon is a block item, the mill's particles and grinding sound use that block. Each item of a `chance` output rolls separately; a weighted choice between items outputs only into an empty slot.

## Fields

| Field | Meaning and default | Range |
| - | - | - |
| `type` | Selects the `hbm:rock_mill` recipe format. | |
| `name` (Optional) | Internal lookup name; defaults to the last segment of the recipe resource path. | |
| `input_items` (Optional) | Ordered counted item inputs; defaults to an empty list. | |
| `input_items.ingredient` | Item ID, item tag, or loader ingredient object. | |
| `input_items.count` (Optional) | Items required from one stack; default 1. The item stack limit bounds a usable count. | `[1, i32::MAX]` |
| `input_items.components` (Optional) | Exact item-component values. | |
| `input_items.predicates` (Optional) | Item-component predicates. | |
| `input_fluids` (Optional) | Ordered fluid inputs with amount and pressure; defaults to an empty list. | |
| `input_fluids.type` | Registered fluid ID. | |
| `input_fluids.amount` | Amount in mB; use $[1, \mathrm{tank\ capacity}]$ for transfers because machine code casts to int. | `i64` |
| `input_fluids.pressure` (Optional) | Pressure level; default 0. | `i32` |
| `output_items` (Optional) | Fixed or weighted item-output positions; defaults to an empty list. | |
| `output_items.item ID` | Fixed output: String form for one item. | |
| `output_items.id` | Item ID in a stack object. | |
| `output_items.count` (Optional) | Stack size; default 1. | `[1, 99]` |
| `output_items.components` (Optional) | Item-component values. | |
| `output_items.chance` (Optional) | Output chance; omit for a guaranteed output. Some machines roll each item of the stack separately. | Rounds to weight `[1, 999]` of 1000 |
| `output_items.data` | Weighted choice: Stack object or an empty object for no output. | |
| `output_items.weight` | Relative selection weight; a positive total selects an output. | `[0, i32::MAX]` each; $\sum_i w_i \le \texttt{i32::MAX}$ |
| `output_fluids` (Optional) | Ordered fluid outputs with amount and pressure; defaults to an empty list. | |
| `output_fluids.type` | Registered fluid ID. | |
| `output_fluids.amount` | Amount in mB; use $[1, \mathrm{tank\ capacity}]$ for transfers because machine code casts to int. | `i64` |
| `output_fluids.pressure` (Optional) | Pressure level; default 0. | `i32` |
| `duration` | Process duration in ticks; defaults to 0. | `i32` |
| `power` | HE demand; defaults to 0. | `i64` |
| `icon` (Optional) | Stack template displayed for the recipe; otherwise derived from the output. | |
| `icon.id` | Item ID. | |
| `icon.count` (Optional) | Stack size; default 1. | `[1, 99]` |
| `icon.components` (Optional) | Item-component values. | |
| `icon_from_input` (Optional) | Derives the display icon from the first item input when true; defaults to false. | |
| `name_wrapper` (Optional) | Translation key applied around the displayed recipe name. | |
| `custom_localization` (Optional) | Resolves the internal name as a translation key when true; defaults to false. | |
| `blueprint_pools` (Optional) | Blueprint pools containing the recipe; a pooled recipe needs a blueprint of one of them in the machine. | |
| `blueprint_pools_528` (Optional) | Replaces blueprint_pools while the enable_528 flag holds. | |
| `auto_switch_group` (Optional) | Translation key grouping recipes; the machine switches to the group member whose first item input matches its first input slot. | |
| `order` (Optional) | Sort position within the recipe table; lower values first, default 2147483647. | `i32` |

## Example

Source path: `data/hbm/recipe/rock_mill/rock.cobble.json`

```json
{
  "type": "hbm:rock_mill",
  "auto_switch_group": "autoswitch.crushing",
  "duration": 100,
  "icon_from_input": true,
  "input_fluids": [
    {
      "type": "minecraft:water",
      "amount": 250
    }
  ],
  "input_items": [
    {
      "ingredient": "#c:cobblestones"
    }
  ],
  "name_wrapper": "rock.crushing",
  "order": 0,
  "output_fluids": [
    {
      "type": "hbm:colloid",
      "amount": 250
    }
  ],
  "output_items": [
    [
      {
        "data": {
          "id": "minecraft:gravel"
        },
        "weight": 95
      },
      {
        "data": {
          "id": "hbm:powder_quartz"
        },
        "weight": 5
      }
    ]
  ],
  "power": 25
}
```