Datapack Guide

Datapack Guide

The rules Material Nexus works from are datapack data, under data/<namespace>/material_nexus/. A pack, a datapack or another mod can add files, or replace a shipped one by using the same id in a pack loaded later. Changes apply on /reload.

Folder	Says
forms/	which tag folders and item names make a form, and how forms convert into each other
recipe_formats/	where a mod's recipes keep their items, so they can be rewritten
process_templates/	how to write a machine's recipe when there is none to copy
presets/	ready-made pack-wide settings
materials/	other names of a material

Editing in game

The Rule files view (under Advanced) lists every one of these files, grouped by kind, with where the version in use comes from. Editing one saves your version in config/materialnexus/policies/data/ (a datapack named materialnexus_user, loaded on top), as a change to apply; Back to original removes your version. Your edits are decoded before being written, and the history keeps them.

Forms

{
  "folders": { "ore_chunks": "ore_chunk" },
  "patterns": { "double_ingot": ["modern_industrialization:{material}_double_ingot"] },
  "relations": [{ "from": "tiny_dust", "to": "dust" }],
  "remove_relations": [{ "from": "dust", "to": "ingot" }],
  "remove_folders": ["sheetmetals"]
}

• folders: a convention tag folder and the form it holds (c:ore_chunks/<material>). Adds to the built-in ones or remaps one.
• remove_folders: folders no longer read, built-in ones included; that form disappears from the pack view.
• patterns: item ids of a form mods leave untagged; {material} stands for a material some tag already knows. A match counts as evidence for that form; nothing is added to the game's tags.
• relations / remove_relations: conversions checked by the Missing tab and the report.

Built-in folders: ores, raw_materials, storage_blocks, ingots, nuggets, gems, dusts, tiny_dusts, dirty_dusts, clumps, shards, crystals, plates, sheetmetals, rods, gears, wires, double_ingots, large_plates, curved_plates, bolts, rings, blades, rotors, drill_heads, fine_wires. Built-in relations: nugget and ingot, ingot and block, raw and raw block, raw to ingot, dust to ingot, gem and block. Shipped pattern files: Modern Industrialization, Oritech, Realistic Minerals.

The Untagged forms tab of Rule files and the end of the report list name shapes worth declaring.

Recipe formats

{ "types": ["othermod:grinder", "othermod:press"], "outputs": ["product", "byproducts"] }

types: the recipe types this format describes. outputs: the top-level keys holding the items a recipe produces. With a format, Material Nexus rewrites those recipes (outputs and inputs) when they involve an alternative; without one, they are listed as "not handled yet" and left untouched.

Process templates

One file per machine:

{
  "machine": "immersiveengineering:metal_press",
  "forms": {
    "rod": { "mold": "immersiveengineering:mold_rod" },
    "plate": { "mold": "immersiveengineering:mold_plate" }
  },
  "recipe": {
    "type": "immersiveengineering:metal_press",
    "energy": 2400,
    "input": { "basePredicate": "${input}", "count": "${in}" },
    "mold": "${mold}",
    "result": { "basePredicate": { "item": "${output_item}" }, "count": "${out}" }
  }
}

Field
machine	the recipe type routes name
prefer	true: use the template before trying to copy a recipe
forms	variables per output form; a template with forms only serves those forms
patterns	shaped crafting patterns by input count: {"3": ["#", "#", "#"]}
recipe	the recipe, with placeholders

Placeholders: ${input} (the input form's tag, else its kept item), ${inputs} (that ingredient repeated in times), ${in}, ${out}, ${pattern}, ${output_item}, ${output_tag}, ${material}, ${form}, and the form's variables. A key "${input}" merges the ingredient into its object: { "amount": "${in}", "${input}": "" } for stacks written that way.

A filled template is kept only if reading it back gives the exact ratio and the game decodes it.

Presets

A partial global.json:

{ "mod_priority": ["mekanism", "minecraft"], "conversion_recipes": ["ingot", "nugget"] }

Its name and description come from the lang keys materialnexus.preset.<id> and materialnexus.preset.<id>.desc. Using a preset sets the fields it defines and keeps the others.

Materials

{ "id": "aluminum", "aliases": ["aluminium"] }

Tags named after an alias (c:ingots/aluminium) are discovered as the declaring material. Aliases are never guessed from names. Shipped: aluminium as aluminum.