Liquid Generator

The Example Biofuel Generator converts each millibucket of example_biofuel into 30 DE. It has one fixed liquid tank, no item inventory, and six independently configured liquid input faces.

This tutorial uses the template's single-block generator and applies the fixed-type pattern also used by its Biofuel Dynamo. Fixing the tank type prevents another valid liquid from occupying the empty fuel tank.

1. Register the resource first

The generator depends on the registrations and assets from Fluids and gases:

utilitycraft:example_biofuel_capsule
utilitycraft:example_empty_fluid_capsule
liquid type example_biofuel
display items and textures utilitycraft:example_biofuel_00 through _48
utilitycraft:fluid_tank_example_biofuel BP and RP entities

Confirm a capsule can fill and empty a UtilityCraft fluid tank before debugging generation.

2. Configure the block

The important part of the template block is:

BP/blocks/examples/example_biofuel_generator.json
{
  "description": {
    "identifier": "utilitycraft:example_biofuel_generator",
    "traits": {
      "minecraft:placement_direction": {
        "enabled_states": ["minecraft:cardinal_direction"],
        "y_rotation_offset": 180
      }
    },
    "states": {
      "utilitycraft:on": [false, true]
    }
  },
  "components": {
    "utilitycraft:fluid_container": {},
    "utilitycraft:example_biofuel_generator": {
      "entity": {
        "name": "example_biofuel_generator",
        "type": "fluid_generator",
        "inventory_size": 9,
        "fixed_fluid_types": true
      },
      "generator": {
        "energy_cap": 128000,
        "rate_speed_base": 80,
        "fluid_cap": 16000,
        "fluid_types": 1
      }
    },
    "minecraft:tick": {
      "interval_range": [4, 4]
    },
    "tag:dorios:generator": {},
    "tag:dorios:io": {},
    "tag:utilitycraft:io.example_biofuel_generator": {},
    "tag:dorios:energy": {},
    "tag:dorios:fluid": {}
  }
}

Add fixed_fluid_types: true to the current template block when following this single-purpose version. The component creates one 16,000 mB tank at liquid index 0 and one 128,000 DE energy buffer.

The complete template file also has six face textures, cardinal rotations, an on-state permutation, collision, mining settings, and the tool tag. Keep them unchanged.

Slot and index layout

Kind	Slot or index	Purpose
Energy display	slot `0`	Internal Dorios Energy.
Label	slot `1`	Live generator status.
Liquid display	slot `2`	Biofuel bar frame.
Liquid storage	index `0`	Actual biofuel amount and type.
Liquid IO buttons	slots `3–8`	Six relative faces.

The liquid display slot and liquid storage index are different concepts. fuel.display(2) reads tank index 0 and writes its frame item into inventory slot 2.

3. Register liquid IO

BP/scripts/examples/generators/biofuelGenerator.js
// @ts-check

import {
  EnergyStorage,
  FluidStorage,
  Generator,
  registerIOInterface,
} from "DoriosCore/index.js";
import * as DoriosLib from "DoriosLib/index.js";

const BLOCK_ID = "utilitycraft:example_biofuel_generator";
const FUEL_TYPE = "example_biofuel";
const ENERGY_PER_MB = 30;
const FLUID_INDEX = 0;
const FLUID_DISPLAY_SLOT = 2;
const LIQUID_IO_BUTTON_SLOTS = [3, 8];

registerIOInterface(BLOCK_ID, {
  liquids: {
    buttonSlots: LIQUID_IO_BUTTON_SLOTS,
    anyInputIndices: [FLUID_INDEX],
    anyOutputIndices: [],
    modes: [
      { id: "disabled" },
      { id: "fuel", inputIndices: [FLUID_INDEX] },
    ],
  },
});

buttonSlots: [3, 8] resolves to exactly six slots. Liquid policies use tank indices, so inputIndices: [0] is correct; using display slot 2 there would route to a nonexistent third tank.

4. Spawn fixed storage

Continue in the same file:

BP/scripts/examples/generators/biofuelGenerator.js
function spawnBiofuelGenerator(event, settings) {
  Generator.spawnEntity(event, settings, (entity) => {
    const fuel = FluidStorage.initializeSingle(entity);
    if (fuel.type === "empty") fuel.setType(FUEL_TYPE);
    fuel.display(FLUID_DISPLAY_SLOT);
  });
}

The constant-type tag comes from fixed_fluid_types. Assigning example_biofuel once means normal IO rejects other liquid types even when the amount reaches zero.

5. Convert only usable fuel

Complete the component:

BP/scripts/examples/generators/biofuelGenerator.js
DoriosLib.registry.blockComponent(BLOCK_ID, {
  beforeOnPlayerPlace(event, { params: settings }) {
    spawnBiofuelGenerator(event, settings);
  },

  onTick({ block }, { params: settings }) {
    const generator = new Generator(block, settings);
    if (!generator.valid) return;

    generator.processIO();
    generator.energy.transferToNetwork(generator.rate * 4);

    const fuel = FluidStorage.initializeSingle(generator.entity);
    fuel.display(FLUID_DISPLAY_SLOT);

    if (fuel.type !== FUEL_TYPE || fuel.get() <= 0) {
      generator.off();
      generator.displayEnergy();
      generator.setLabel("§r§eNeeds Example Biofuel");
      return;
    }

    if (generator.energy.getFreeSpace() <= 0) {
      generator.off();
      generator.displayEnergy();
      generator.setLabel("§r§eEnergy Full");
      return;
    }

    const consumed = Math.min(
      Math.floor(fuel.get()),
      Math.floor(generator.rate / ENERGY_PER_MB),
      Math.floor(generator.energy.getFreeSpace() / ENERGY_PER_MB),
    );

    if (consumed <= 0) {
      generator.off();
      generator.displayEnergy();
      generator.setLabel("§r§eNeeds 30 DE Free Space");
      return;
    }

    const produced = consumed * ENERGY_PER_MB;
    fuel.consume(consumed);
    generator.energy.add(produced);
    const producedPerTick = produced / generator.processingInterval;

    fuel.display(FLUID_DISPLAY_SLOT);
    generator.on();
    generator.displayEnergy();
    generator.setLabel([
      "§r§aBiofuel Generator Running",
      `§r§7Fuel: §f${FluidStorage.formatFluid(fuel.get())}`,
      `§r§7Produced: §f${EnergyStorage.formatEnergyToText(producedPerTick)}/t`,
    ]);
  },

  onPlayerBreak(event) {
    Generator.onDestroy(event);
  },
});

The three limits are whole stored millibuckets, the scheduled energy budget converted to millibuckets, and free capacity converted to millibuckets. If only 1 mB remains, the generator produces 30 DE and consumes exactly that millibucket. If the energy buffer has room for only 15 DE, it pauses until at least 30 DE is free.

FluidStorage uses whole millibucket scoreboard values. Keeping consumption integral prevents a fractional request from rounding into an extra consumed millibucket. Never consume fuel before calculating the complete storable conversion.

6. Display fuel and IO

The template's standard panel uses slot 2 and the liquid fuel outline:

RP/ui/example_machinery.json
{
  "biofuel_generator_top": {
    "type": "collection_panel",
    "size": [162, 72],
    "offset": [-10, -40],
    "collection_name": "container_items",
    "$item_collection_name": "container_items",
    "controls": [
      { "machine_name@uc.machine_name": {} },
      { "machine_screen@uc.machine_small_screen": {} },
      {
        "machine_description@uc.text_label": {
          "collection_index": 1,
          "anchor_from": "top_left",
          "anchor_to": "top_left",
          "size": [48, 48],
          "$text_scale": 0.55,
          "offset": [14, 12]
        }
      },
      { "energy_bar@uc.energy_bar": { "offset": [32, 0], "$has_bg": false } },
      {
        "fuel@uc.liquid_fuel_bar": {
          "$collection_index": 2,
          "$has_bg": false,
          "offset": [54, 0]
        }
      },
      {
        "io@uc.io_tab": {
          "$has_item_io": false,
          "$has_fluid_io": true,
          "$has_gas_io": false,
          "$io_fluids_modes_description": "ui.utilitycraft:io.example_biofuel_generator.liquids",
          "$io_top_texture": "textures/blocks/examples/biofuel_generator_off_up",
          "$io_left_texture": "textures/blocks/examples/biofuel_generator_off_west",
          "$io_front_texture": "textures/blocks/examples/biofuel_generator_off_north",
          "$io_right_texture": "textures/blocks/examples/biofuel_generator_off_east",
          "$io_bottom_texture": "textures/blocks/examples/biofuel_generator_off_down",
          "$io_back_texture": "textures/blocks/examples/biofuel_generator_off_south",
          "$io_fluid_top_index": 3,
          "$io_fluid_left_index": 4,
          "$io_fluid_front_index": 5,
          "$io_fluid_right_index": 6,
          "$io_fluid_bottom_index": 7,
          "$io_fluid_back_index": 8
        }
      },
      {
        "info@uc.info_tab": {
          "$info_description": "ui.utilitycraft:info.example_biofuel_generator"
        }
      }
    ]
  }
}

UI Core retains the older $has_fluid_io, $io_fluids_*, and $io_fluid_* names. The DoriosCore registration uses liquids. This distinction is intentional.

The template already routes entity.utilitycraft:example_biofuel_generator.name to this panel and supplies:

RP/texts/en_US.lang
tile.utilitycraft:example_biofuel_generator.name=Example Biofuel Generator\n§o§9@UC: Addon Template
entity.utilitycraft:example_biofuel_generator.name=Example Biofuel Generator
ui.utilitycraft:info.example_biofuel_generator=Consumes §gExample Biofuel§8 to generate §sDorios Energy§8. Each liquid unit provides 30 DE, and generation pauses when the tank is empty or energy storage is full.
ui.utilitycraft:io.example_biofuel_generator.liquids=§rLiquid I/O Modes:\n§r- §vBiofuel Input

7. Test liquid generation

Fill the generator with an Example Biofuel Capsule.
Confirm other registered liquids are rejected by the fixed tank.
Configure one face as fuel and pull biofuel from an adjacent tank.
Confirm every 1 mB consumed produces 30 DE in total.
Leave less than 30 DE free and verify the generator pauses without consuming a millibucket.
Disable the face and confirm automatic transfer stops.
Break and replace the generator; verify energy and liquid are preserved in resource lore.

Continue with Gas Generator.

1. Register the resource first​

2. Configure the block​

Slot and index layout​

3. Register liquid IO​

4. Spawn fixed storage​

5. Convert only usable fuel​

6. Display fuel and IO​

7. Test liquid generation​