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Quick Setup Guide – Inventory System ​

This guide walks you through the minimal steps to get the Inventory System running in your Unreal Engine project.

1. Add the Inventory Component to an Actor ​

  1. Open your actor in the editor.
  2. Add a UInventoryComponentBase component.
  3. Configure the Inventory Size property (number of slots).
cpp
UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Inventory")
UInventoryComponentBase* InventoryComponent;

2. Create Inventory Items ​

You can use either Authored Items (shared assets) or Instanced Items (unique per actor).

  • Authored Items: Create a UInventoryObjectBase asset and assign it directly.
  • Instanced Items: Add an Item Component to the actor and set bUseInstancedItem = true.
cpp
UFUNCTION(BlueprintPure, Category = "Item")
UInventoryObjectBase* GetItem() const { return bUseInstancedItem ? InstancedItem : Item; }

3. Add Items to Inventory ​

Use the AddItem function on your inventory component.

cpp
int32 RemainingAmount;
InventoryComponent->AddItem(MyItemObject, 5, RemainingAmount);

4. Remove or Use Items ​

  • Remove:
cpp
int32 RemainingAmount;
InventoryComponent->RemoveItem(MyItemObject, 2, RemainingAmount);
  • Use:
cpp
InventoryComponent->UseItem(MyItemObject, 1);
  • You can also perform these actions by index:
cpp
InventoryComponent->UseItemAtIndex(0, 1, true); // bUseLocalIndex = true

5. Transfer Items Between Inventories ​

cpp
InventoryComponent->TransferItem(MyItemObject, 1, TargetInventoryComponent);

6. Drop Items ​

cpp
InventoryComponent->DropItem(MyItemObject, 1);
  • Supports dropping by object or by slot index.
  • Triggers the item’s OnDrop function if implemented.

7. Hooks & Delegates ​

  • Blueprint Events:

    • K2_OnItemAdded
    • K2_OnItemRemoved

  • Delegates for UI / Event-Driven Updates:

    • OnItemChanged_Delegate
    • OnItemRemovedFromInventoryDelegate
    • OnItemAddedToInventoryDelegate