Use Only Part of the Inventory

Documentation Unreal Engine Player Combat Inventory Quick Bar

Each part of the UPC inventory is something you add, so a game takes only the parts it plays with: a belt alone needs no config and no screen, and bags, combines, chests and saving are each optional.

Set it up

3 minutes
  1. 1

    Leave the inventory with no config

    Clear Config on BP_UPC_Character's InventoryComponent. The inventory becomes one unlimited list: every pickup fits.
  2. 2

    Let the belt take any item

    On BP_UPC_PlayerController's QuickBarComponent, clear the Filter on each of the four Slots. Auto Populate from Inventory is already on, so a new item takes the first free slot.
    QuickBarComponent
    ▾Slots
    Index [ 0 ] > FilterUPC.Slot.Weapon
    Index [ 1 ] > FilterUPC.Slot.Consumable.Potion
    Index [ 2 ] > FilterUPC.Slot.OffHand
    Index [ 3 ] > FilterUPC.Slot.Consumable
  3. 3

    Press Play and pick things up

    Take the swords and the shield off the weapon rack, and press F at the loot chest. Each item takes the next free slot, one copy of each (the demo belt's Default Max Copies Per Definition is 1), and keys 1 to 4 draw, put on or use them. An item no slot takes stays in the inventory, which only the inventory screen (I) shows; Leave out a part removes the screen too.

A belt and nothing else

With no Config, the inventory keeps everything the character picks up in one list; the belt's slots only decide what gets a key. An item no slot takes (belt full, no Filter matches) stays in the list and the pickup still succeeds:
SlotsPlays likeWhat lands where
No Filter on any slotA survival game's hotbarAny item takes the next free slot; a ring's key puts it on.
A Filter per slotThe demo's souls-like diamondOne kind per slot: a weapon, a potion, an off-hand item, another consumable. A second sword takes the off-hand slot; worn gear stays in the inventory.
Quick Bar covers Filter matching.
To carry only what the belt holds and the gear the character wears, use InventoryConfig_UPC_Simple, the demo player's. Its Belt list has the Belt Only rule, which takes an item only while a belt slot takes it, and the belt's Auto Populate puts it there; five Worn slots, whose Item Filter takes only apparel, hold the gear the diamond has no slot for. Anything else, such as a herb, reads Can't Carry, a sixth potion Can't Carry More, and with the slots for its kind held a pickup swaps for the item in the way (Swap When Full, on). It opens no inventory screen.
Demo item kinds
The belt, the inventory's rules and its sort read one hierarchy of kinds:
KindDemo items
UPC.Slot.Weapon (.Sword, .TwoHanded)The swords and the two-handed baton
UPC.Slot.OffHand (.Shield)The shield, and the one-handed sword beside its weapon kind
UPC.Slot.Consumable (.Potion)The potion and the mixed herb
UPC.Slot.ApparelThe helmet, the shoulder cape, the necklace and the ring
UPC.Slot.IngredientThe herb and the poison
UPC.Slot.Ammo (.Arrow)The rounds, the magazine, the arrows and the poison arrows
UPC.Slot.KeyItem, UPC.Slot.UpgradeThe key, and the pouch

Leave out a part

To go withoutLeave out
LimitsConfig; or, with a config, the Carry Rules (limits on everything carried), each container's Rules, and every layout but List (Containers and Rules).
A gridGrid layouts and Grid Footprint fragments.
Turning in a gridAllow Rotation on the grid.
BagsOpens Bags, the container setting that lets a bag placed there open its own container, on every container; or the item's Container fragment (Bags and Banks).
Storage off the characterContainers with Carried off.
CombinesThe config's Combine Sets; a drop then joins stacks or trades places.
ChestsActors with a UPC World Inventory, a chest's own inventory (Loot Chests).
SavingExport Snapshot and Import Snapshot.
A screenThe IA_UPC_Inventory rows in the Input Mapping Context your character adds (IMC_UPC_Default for the demo character), and the OpenInventory options on boxes and chests. Pickups, the belt and the rules work without one.
The beltA player controller of your own that does not inherit UPCPlayerController (which creates the UPC Quick Bar itself), or a config with Has Belt off. With no belt on the controller, the character base's Draw Starting Items draws the starting items; under Has Belt off a belt with Auto Populate from Inventory on draws none (Equipment).
A player carrying only the item in hand: One Item at a Time. For most parts, start from a ready style and remove what you do not use.