Use with LootComponent

The Loot System and Respawn Manager are designed to work together:

Loot System decides what drops
Respawn Manager decides when the source comes back

This page shows how to connect:

LootTable + LootComponent (UMI)
RespawnManagerSubsystem (Respawn Manager)

…to create renewable:

Resource nodes (trees, rocks, ore veins)
Harvestable world objects (plants, mushrooms, bushes)
Chests/containers that refill over time

Enemies are usually single-use loot + separate enemy spawn/respawn logic. We’ll touch on that pattern at the end.

1. High-Level Pattern

For any loot source you want to respawn:

Harvest/Interact
   ↓
Generate loot via LootComponent
   ↓
Give loot to player or spawn WorldItemActor
   ↓
Mark actor as inactive (hide, disable collision, block interaction)
   ↓
Register respawn with Respawn Manager
   ↓
Respawn Manager waits…
   ↓
OnRespawnRequested → Actor resets loot + visuals

So:

LootComponent = “What dropped?”
Respawn Manager = “When does this node come back?”

2. Required Components

On your loot source actor (e.g., BP_Tree, BP_Rock, BP_OreNode, BP_BerryBush):

ULootComponent – which uses a LootTable (e.g. LT_TreeLoot)
(Recommended) implements BPI_Respawnable / IRespawnable
A mesh or visual component you can hide/show
A collision/interaction component to enable/disable
A RespawnTime float

Example:

Components:
- StaticMesh (TreeMesh)
- LootComponent (LootComponent)
Variables:
- RespawnTime = 300.0
- bHasBeenHarvested (bool)

3. Resource Node Pattern (Tree/Rock/Ore)

3.1 Tree Example — Blueprint Flow

On Harvest:

Event OnHarvested
   ↓
Branch: bHasBeenHarvested?
   True → Return
   False →
       Set bHasBeenHarvested = true
       ↓
       LootComponent → Generate Loot
           → Loot Result
       ↓
       Give items to player (Add to Inventory / Spawn WorldItemActor)
       ↓
       Hide Mesh (Set Visibility = false)
       Disable Collision
       Disable Interaction
       ↓
       Get RespawnManagerSubsystem
           → Register Respawn Request
              Target Actor = Self
              Delay        = RespawnTime

On Respawn:

Event OnRespawnRequested  (from BPI_Respawnable)
   ↓
Set bHasBeenHarvested = false
LootComponent → Reset Loot
Show Mesh
Enable Collision
Enable Interaction

That’s literally enough to have infinite renewable trees.

3.2 Rock/Ore Example — C++

Header:

UCLASS()
class YOURGAME_API AOreNode : public AActor, public IRespawnable
{
    GENERATED_BODY()

public:
    void OnHarvested(APlayerController* Harvester);

    virtual void OnRespawnRequested() override;

protected:
    UPROPERTY(VisibleAnywhere)
    UStaticMeshComponent* Mesh;

    UPROPERTY(VisibleAnywhere)
    ULootComponent* LootComponent;

    UPROPERTY(EditAnywhere, Category="Respawn")
    float RespawnTime = 300.0f;

    bool bHasBeenHarvested = false;
};

Source:

void AOreNode::OnHarvested(APlayerController* Harvester)
{
    if (bHasBeenHarvested) return;
    bHasBeenHarvested = true;

    // Generate loot
    FLootResult Loot = LootComponent->GenerateLoot();
    if (AMyCharacter* Character = Cast<AMyCharacter>(Harvester->GetPawn()))
    {
        for (const FLootedItem& Item : Loot.SpawnedItems)
        {
            Character->InventoryComponent->AddItem(Item.ItemData, Item.Quantity);
        }
    }

    // Disable node
    Mesh->SetVisibility(false);
    Mesh->SetCollisionEnabled(ECollisionEnabled::NoCollision);

    // Register respawn
    if (URespawnManagerSubsystem* RM = GetWorld()->GetSubsystem<URespawnManagerSubsystem>())
    {
        RM->RegisterRespawnRequest(this, RespawnTime);
    }
}

void AOreNode::OnRespawnRequested()
{
    bHasBeenHarvested = false;

    // Reset loot
    LootComponent->ResetLoot();

    // Re-enable node
    Mesh->SetVisibility(true);
    Mesh->SetCollisionEnabled(ECollisionEnabled::QueryAndPhysics);
}

4. Chests & Containers

You probably want two behaviors for chests:

Single-use chest (dungeon chest, boss chest):
- Uses LootComponent
- bSingleUse = true
- No respawn → just disabled once looted
Respawnable chest (world chests, camp chests):
- Uses LootComponent
- bSingleUse = false
- Registers with Respawn Manager after being looted

4.1 Blueprint: Single-use Chest (No Respawn)

Event OnOpenChest
   ↓
LootComponent → Generate Loot
   → Loot Result
   ↓
Add items to player inventory
   ↓
LootComponent → MarkAsLooted (internally handled)
   ↓
Disable interaction / Change mesh to "opened"
   ↓
(Optional) Destroy actor later

No respawn request is sent.

4.2 Blueprint: Respawnable Chest

On Chest Looted:

Event OnChestOpened
   ↓
LootComponent → Generate Loot
   → Loot Result
   ↓
Give loot to player
   ↓
Set bIsOpen = true
Change to "opened" mesh or animation
Disable interaction
   ↓
Get RespawnManagerSubsystem
   → Register Respawn Request
      Target Actor = Self
      Delay        = RespawnTime

On Respawn:

Event OnRespawnRequested
   ↓
Set bIsOpen = false
LootComponent → Reset Loot
Change to "closed" mesh
Enable interaction

This gives you camp chests that refill on a timer.

5. Enemy Loot vs Enemy Respawn

Important distinction:

Loot System handles what drops when an enemy dies
Respawn Manager should not respawn the enemy itself directly (usually)

Typical pattern:

Enemy has a LootComponent
On death:
- LootComponent → GenerateLoot
- Spawn WorldItemActors around corpse, or auto-loot to players
Enemy does not register itself with Respawn Manager
A separate spawner or manager uses Respawn Manager to handle enemy respawn

5.1 Enemy Death + LootComponent

Blueprint:

Event OnDeath
   ↓
LootComponent → Generate Loot
   → Loot Result
   ↓
For each item:
    Spawn WorldItemActor at random offset
   ↓
Destroy enemy (or hide corpse)

No respawn scheduling here.

5.2 Enemy Spawner + Respawn Manager

Spawner actor:

void AEnemySpawner::OnEnemyDied()
{
    if (URespawnManagerSubsystem* RM = GetWorld()->GetSubsystem<URespawnManagerSubsystem>())
    {
        RM->RegisterRespawnRequest(this, RespawnDelay);
    }
}

void AEnemySpawner::OnRespawnRequested()
{
    SpawnEnemy();
}

So:

LootComponent = enemy drops
Respawn Manager = when spawner creates a new enemy

Cleaner separation, especially for multiplayer & save/load.

6. WorldItemActor & Decay

You can also mix loot → world items → decay with respawns:

LootComponent generates items
You spawn WorldItemActors using InventoryComponent → SpawnWorldItem()
WorldItemActor runs decay/spoilage logic (UMI)
When items expire, you may (optionally) have the spawn point schedule a respawn via Respawn Manager, if you want periodic “drop piles” in the world

This is more niche, but the pattern is:

LootComponent → WorldItemActor
WorldItemActor decays and destroys itself
Spawner or node schedules next respawn

7. Common Gotchas

❌ Forgetting to call `ResetLoot()` on respawn

Result: chest respawns visually but drops nothing (or keeps old state).
Fix: Always call LootComponent → Reset Loot in OnRespawnRequested.

❌ Using per-actor timers + Respawn Manager together

Result: duplicated logic, inconsistent behavior.
Fix: Pick one pattern. For anything integrated with Respawn Manager, let only the manager handle timing.

❌ Not disabling collision/interaction on harvested nodes

Result: invisible objects blocking the player or still interactable.
Fix: On harvest/loot: hide mesh, disable collision, disable interaction.

❌ Trying to respawn enemies directly with LootComponent

Respawn Manager should be used with spawners or respawn points, not with dead pawns themselves.
Keep loot and respawn responsibility separated.

8. Best Practice Recipes

Renewable Resource Node

Actor: BP_Tree, BP_Rock, BP_OreNode
Components: StaticMesh, LootComponent
Interface: BPI_Respawnable
Flow:
- On harvest: GenerateLoot → give items → hide/disable → register respawn
- On respawn: ResetLoot → show/enable

Renewable Loot Chest

Actor: BP_CampChest
Components: StaticMesh, LootComponent
Variables: RespawnTime, bIsOpen
Flow:
- On open: generate loot, give to player, mark open, disable interaction, register respawn
- On respawn: reset loot, mark closed, enable interaction

Single-Use Boss Chest

Actor: BP_BossChest
LootComponent with Legendary-weighted LootTable
bSingleUse = true
No respawn registration
Optional: destroy chest after opening

9. Summary

LootComponent + LootTable decide what is dropped.
Respawn Manager decides when the loot source comes back.
Resource nodes and chests are the main candidates for Respawn Manager + Loot integration.
Enemies should use LootComponent for drops, and separate spawners for enemy respawn.

Installation & Setup

Core Concepts

Crafting System

Equipment System

Hotbar & Quick Actions

Interaction System

Inventory Component

Loot System

Merchant System

Respawn Manager

Saving & Loading

1. High-Level Pattern

2. Required Components

3. Resource Node Pattern (Tree/Rock/Ore)

3.1 Tree Example — Blueprint Flow

3.2 Rock/Ore Example — C++

4. Chests & Containers

4.1 Blueprint: Single-use Chest (No Respawn)

4.2 Blueprint: Respawnable Chest

5. Enemy Loot vs Enemy Respawn

5.1 Enemy Death + LootComponent

5.2 Enemy Spawner + Respawn Manager

6. WorldItemActor & Decay

7. Common Gotchas

❌ Forgetting to call `ResetLoot()` on respawn

❌ Using per-actor timers + Respawn Manager together

❌ Not disabling collision/interaction on harvested nodes

❌ Trying to respawn enemies directly with LootComponent

8. Best Practice Recipes

Renewable Resource Node

Renewable Loot Chest

Single-Use Boss Chest

9. Summary

​1. High-Level Pattern

​2. Required Components

​3. Resource Node Pattern (Tree/Rock/Ore)

​3.1 Tree Example — Blueprint Flow

​3.2 Rock/Ore Example — C++

​4. Chests & Containers

​4.1 Blueprint: Single-use Chest (No Respawn)

​4.2 Blueprint: Respawnable Chest

​5. Enemy Loot vs Enemy Respawn

​5.1 Enemy Death + LootComponent

​5.2 Enemy Spawner + Respawn Manager

​6. WorldItemActor & Decay

​7. Common Gotchas

​❌ Forgetting to call ResetLoot() on respawn

​❌ Using per-actor timers + Respawn Manager together

​❌ Not disabling collision/interaction on harvested nodes

​❌ Trying to respawn enemies directly with LootComponent

​8. Best Practice Recipes

​Renewable Resource Node

​Renewable Loot Chest

​Single-Use Boss Chest

​9. Summary

1. High-Level Pattern

2. Required Components

3. Resource Node Pattern (Tree/Rock/Ore)

3.1 Tree Example — Blueprint Flow

3.2 Rock/Ore Example — C++

4. Chests & Containers

4.1 Blueprint: Single-use Chest (No Respawn)

4.2 Blueprint: Respawnable Chest

5. Enemy Loot vs Enemy Respawn

5.1 Enemy Death + LootComponent

5.2 Enemy Spawner + Respawn Manager

6. WorldItemActor & Decay

7. Common Gotchas

❌ Forgetting to call `ResetLoot()` on respawn

❌ Using per-actor timers + Respawn Manager together

❌ Not disabling collision/interaction on harvested nodes

❌ Trying to respawn enemies directly with LootComponent

8. Best Practice Recipes

Renewable Resource Node

Renewable Loot Chest

Single-Use Boss Chest

9. Summary