Configure the Six Faces

registerIOInterface() created six button definitions. The standard IO tab renders them in this exact order:

Position	Relative face	Crusher button slot
1	Top	9
2	Left	10
3	Front	11
4	Right	12
5	Bottom	13
6	Back	14

Changing the order in either the script or JSON UI makes the visible face control a different physical side.

Add the item IO tab

Add this control to the Thermal Crusher's crusher_top.controls array created in Machine UI:

RP/ui/first_machine_ui.json

{
  "io@uc.io_tab": {
    "$has_io_config": true,
    "$has_item_io": true,
    "$has_fluid_io": false,
    "$has_gas_io": false,
    "$io_items_modes_description": "ui.utilitycraft:io.example_thermal_crusher.items",
    "$io_top_texture": "textures/blocks/examples/thermal_crusher_off_up",
    "$io_left_texture": "textures/blocks/examples/thermal_crusher_off_west",
    "$io_front_texture": "textures/blocks/examples/thermal_crusher_off_north",
    "$io_right_texture": "textures/blocks/examples/thermal_crusher_off_east",
    "$io_bottom_texture": "textures/blocks/examples/thermal_crusher_off_down",
    "$io_back_texture": "textures/blocks/examples/thermal_crusher_off_south",
    "$io_item_top_index": 9,
    "$io_item_left_index": 10,
    "$io_item_front_index": 11,
    "$io_item_right_index": 12,
    "$io_item_bottom_index": 13,
    "$io_item_back_index": 14
  }
}

The six *_index values are the same six slots registered by items.buttonSlots. They are display-button slots, not recipe slots.

Add the mode legend

RP/texts/en_US.lang

ui.utilitycraft:io.example_thermal_crusher.items=§rI/O Modes:\n§r- §9Input\n§r- §cOutput

Every formatted line begins with §r. The colors match the slot-outline convention: blue for input and red for output.

Use one texture per face

The IO diagram represents the block itself. Supply the crusher texture corresponding to each face:

up, west, north, east, down, south

These are separate per-face textures from the Resource Pack. Do not pass an atlas image that contains all six faces.

The UI face names are relative to the placed machine. DoriosCore reads minecraft:cardinal_direction and resolves the selected Front, Left, Right, and Back to the corresponding world direction.

Use invertFaces: true in registerIOInterface() only if a custom model or legacy facing convention intentionally maps every visual face to its opposite physical direction:

registerIOInterface(BLOCK_ID, {
  invertFaces: true,
  items: itemPolicy,
});

The template's Thermal Crusher does not need this option.

How clicking works

No custom button event is required. DoriosCore's interface system:

1. places one protected button item in every registered button slot;
2. writes the current mode ID into its visible name tag;
3. detects when the player presses the container button;
4. advances that face to the next registered mode;
5. persists the new per-face item configuration;
6. restores the button item with its new outline state.

For this crusher, each face cycles:

disabled -> input_1 -> output_1 -> disabled

Every face stores its choice independently. The top can be an input while the right is an output and the remaining faces stay disabled.

Test the complete routing

1. Place the crusher and give it energy.
2. Place one compatible item container against its left face and another against its right face.
3. Open the IO tab.
4. Set Left to the blue input_1 mode.
5. Set Right to the red output_1 mode.
6. Put Cobblestone in the left container.
7. Confirm the crusher pulls it into slot 3.
8. Wait for processing and confirm Gravel leaves slot 4 through the right face.
9. Set Right to disabled and confirm the next output remains inside the crusher.

Transfers occur on valid machine ticks, so a change may not be visible in the same game tick as the click.

Common configuration errors

Exactly six valid slots

RangeError: items.buttonSlots must resolve to exactly six valid slots

Use either an inclusive six-slot range such as [9, 14] or an explicit six-entry array. [9, 10] is interpreted as the inclusive range 9..10, which produces only two slots and fails.

Overlapping slots

Button slots cannot overlap operational inputs or outputs. Separate UI controls, recipe inventory, displays, and upgrades in the helper-entity layout.

Outline disappears after clicking

The selected id has no matching UI Core state, or the visible UI index points to the wrong helper slot. Use exact IDs such as disabled, input_1, and output_1, then compare all six UI indices with buttonSlots.

Wrong physical side moves items

Check the order top, left, front, right, bottom, back, the block's placement-direction trait, and its rotation permutations. Do not reorder indices to compensate for an incorrect block-facing definition.

See the IO interface API for every validation rule and the UI tabs reference for all accepted outline states.

Continue with Liquid IO.