# \[Tutorial\] Basic Inventory/Item System

**URL:** <https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952>\
**Category:** Community & Industry Discussion\
**Tags:** unreal-engine\
**Created:** [April 20, 2014, 8:17pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952 "2014-04-20T20:17:59Z")\
**Posts on this page:** 10\
**Page:** 1

<div class="post-metadata">

**Author:** ![alvarofer0020](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@alvarofer0020](https://forums.unrealengine.com/u/alvarofer0020)\
**Post date:** [April 20, 2014, 8:17pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/1 "2014-04-20T20:17:59Z")

</div>

After finally getting my own inventory system working id figure it would be a good idea to lend back the hand to the community so, Lets begin!

First we need an actor that will serve as our item

**Item Header**

```auto

UCLASS()
class AProojectItem : public AActor
{
	GENERATED_UCLASS_BODY()

public:
	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Item)
	FString ItemName;

	UPROPERTY(EditAnywhere, BlueprintReadOnly, Category = Item)
	int32 Value;

	UFUNCTION(BlueprintImplementableEvent, meta = (FriendlyName = "Item: Used"))
		virtual void Used();

	UFUNCTION(BlueprintImplementableEvent, meta = (FriendlyName = "Item: Dropped"))
		virtual void Dropped();

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Item)
		TSubobjectPtr<class UStaticMeshComponent> Mesh;

	virtual void BeginPlay() OVERRIDE;
	void PickedUp();	
};

```

I used BlueprintImplementableEvent in the Used & Dropped functions so i could override these from a blueprint, since my items are blueprints i dont need to create a function in c++ for each one i just declare it on its blueprint

**Item.cpp**

```auto

AProojectItem::AProojectItem(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{
	Mesh = PCIP.CreateDefaultSubobject<UStaticMeshComponent>(this, TEXT("Mesh"));
	RootComponent = Mesh;
}

void AProojectItem::BeginPlay()
{
	Super::BeginPlay();
	Mesh->SetSimulatePhysics(true);
	Mesh->WakeRigidBody();

}

void AProojectItem::PickedUp()
{
	if (Mesh)
	{
		Mesh->DestroyComponent(); // physical item has been picked up, destroy its visible component
	}
}

```

Now that we have our item actor we need an array to store these into

**Character Header**

```auto

UCLASS(config=Game)
class AProojectCharacter : public ACharacter
{
UPROPERTY(EditAnywhere, Category = Inventory)
		TArray<class AProojectItem*> ItemInventory; // Our Inventory

	virtual void Tick(float DeltaSeconds) OVERRIDE;
        void PickUpItem(AProojectItem* Item);
};

```

Now that we have the array the only thing we need to do is a get a pointer to the spawned item and add it to the array , for this i just do a trace each tick and check if its an Item class

```auto

#include "ProojectItem.h"

void AProojectCharacter::Tick(float DeltaSeconds)
{
	Super::Tick(DeltaSeconds);

	FVector CamLoc;
	FRotator CamRot;

	Controller->GetPlayerViewPoint(CamLoc, CamRot); // Get the camera position and rotation
	const FVector StartTrace = CamLoc; // trace start is the camera location
	const FVector Direction = CamRot.Vector();
	const FVector EndTrace = StartTrace + Direction * 200; 

	// Perform trace to retrieve hit info
	FCollisionQueryParams TraceParams(FName(TEXT("WeaponTrace")), true, this);
	TraceParams.bTraceAsyncScene = true;
	TraceParams.bReturnPhysicalMaterial = true;

	FHitResult Hit(ForceInit);
	if (GetWorld()->LineTraceSingle(Hit, StartTrace, EndTrace, ECC_WorldStatic, TraceParams))
	{
		AProojectItem* NewItem = Cast<AProojectItem>(Hit.GetActor()); // typecast to the item class to the hit actor
		if (bDrawDebugViewTrace)
		{
	      DrawDebugLine(
			GetWorld(),
			StartTrace,
			EndTrace,
			FColor(255, 0, 0),
			false,
			3,
			0,
			1
			);
		}
	

		if (NewItem) // if we hit an item with the trace
		{
			this->PickUpItem(NewItem); // pick it up
		}
	}
	
}

void AProojectCharacter::PickUpItem(AProojectItem* Item)
{
	if (Item)
	{
		ItemInventory.Add(Item); // add it to the array
		Item->PickedUp(); // hide mesh 
	}
}

```

By the end you should have someting like this

[![](https://d3kjluh73b9h9o.cloudfront.net/original/3X/2/f/2f0984456f8dd47c5beb0a68b72c3d6cf62ef2aa.jpeg) ](http://tinypic.com/images/goodbye.jpg)

Remember to call the Used & Dropped events somewhere in c++ so they can be used in the blueprint!

Hope someone finds this useful 🙂

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_665c87da](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_665c87da](https://forums.unrealengine.com/u/anonymous_user_665c87da)\
**Post date:** [April 21, 2014, 4:22am UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/2 "2014-04-21T04:22:18Z")

</div>

WOW! Thanks we could use this and make some needed modification for our game. Very much appreciated.

---

<div class="post-metadata">

**Author:** ![Nocte30](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@Nocte30](https://forums.unrealengine.com/u/Nocte30)\
**Post date:** [April 21, 2014, 6:41am UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/3 "2014-04-21T06:41:07Z")

</div>

thank u very much **alvarofer0020** this is a great improvement :eek:

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_c28f5816](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_c28f5816](https://forums.unrealengine.com/u/anonymous_user_c28f5816)\
**Post date:** [April 22, 2014, 2:21am UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/4 "2014-04-22T02:21:33Z")

</div>

I’ve made a wiki tutorial of this page, which has a couple of changes in it including a node setup that lets you print the players inv so you can test if the items are being picked up:

> **[A new, community-hosted Unreal Engine Wiki](https://forums.unrealengine.com/t/a-new-community-hosted-unreal-engine-wiki/141494)**
>
> After over a year in maintenance mode, the official Unreal Engine Wiki is now permanently offline. These resources now live on a new community-run Unreal Engine Community Wiki — https://unrealcommunity.wiki/! You will be able to find content from...

---

<div class="post-metadata">

**Author:** ![alvarofer0020](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@alvarofer0020](https://forums.unrealengine.com/u/alvarofer0020)\
**Post date:** [May 3, 2014, 9:43pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/5 "2014-05-03T21:43:07Z")

</div>

I finally got working a easier way to give items to the player now you only need to get a reference to your player and give him the item with its name i.e GiveItem(“SodaCan”)

so First we need a database to keep a track of all the items the player can acquire im using a struct with a FString to identify the item and a subclass of our item  
so it can be spawned & added to the inventory

**Database Header**

```auto

USTRUCT()
struct FItemData
{
	GENERATED_USTRUCT_BODY()

	UPROPERTY(EditDefaultsOnly, Category = Item)
	FString ItemName;

	UPROPERTY(EditDefaultsOnly, Category = Item)
		TSubclassOf<class AProojectItem> Item;
};
/**
 * 
 */
UCLASS()
class ADatabase : public AActor
{
	GENERATED_UCLASS_BODY()

	UPROPERTY(EditDefaultsOnly, Category = Database)
	TArray<FItemData> ItemClasses;

	TSubclassOf<class AProojectItem> GetItem(FString ItemName);
	
	
};

```

**Database .cpp**

```auto

#include "Prooject.h"
#include "Database.h"

ADatabase::ADatabase(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{

}

TSubclassOf<class AProojectItem> ADatabase::GetItem(FString ItemName)
{
	for (int i = 0; i <= ItemClasses.Num(); i++) // loop trough the whole DB
	{
	
		if (ItemName == ItemClasses*.ItemName) // if the item exists in our DB, return it
		{
			return ItemClasses*.Item;
			break;

		}
	}

	return NULL; // else dont return anything

}

```

Now that we have our Database FIRST we need to create a Blueprint of our new database class so we can load it from our gamemode , so later we can access it trough our player character

**Gamemode Header**

```auto

#include "Database.h"
#include "ProojectGameMode.generated.h"

UCLASS(minimalapi)
class AProojectGameMode : public AGameMode
{
	GENERATED_UCLASS_BODY()
	TSubclassOf<class ADatabase> GameDBClass; // our DB

	class ADatabase* GameDB;

};

```

**Gamemode CPP**

```auto

#include "Prooject.h"
#include "Database.h"
#include "ProojectGameMode.h"

AProojectGameMode::AProojectGameMode(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{
	static ConstructorHelpers::FObjectFinder<UClass> GameDBBPClass(TEXT("Class'/Game/Blueprints/Items/BP_DB.BP_DB_C'")); // change this to YOUR BP Path
	if (GameDBBPClass.Object != NULL)
	{
         GameDBClass = GameDBBPClass.Object; // assign our class
	 GameDB = GameDBClass->GetDefaultObject<ADatabase>(); // create it
	}

}

```

Now that the DB is properly intialized we can cast to our gamemode and then our DB to get the item

**Character header**

```auto

UFUNCTION()
void GiveItem(FString ItemName);

```

**Character CPP**

```auto

void AProojectCharacter::GiveItem(FString ItemName)
{
		AProojectGameMode* MyGamemode = Cast<AProojectGameMode>(GetWorld()->GetAuthGameMode()); // get our gamemode
		TSubclassOf<class AProojectItem> ItemToGive = MyGamemode->GameDB->GetItem(ItemName); // Call the DB GetItem function
		if (ItemToGive) // if we got a item / its not NULL
		{
			FActorSpawnParameters SpawnInfo;
			SpawnInfo.bNoCollisionFail = true;
			AProojectItem* NewItem = GetWorld()->SpawnActor<AProojectItem>(ItemToGive, SpawnInfo); // spawn it in the world so we can pick it
			ItemInventory.Add(NewItem);
			NewItem->PickedUp(); // Its been added to our inventory, we can hide its physical side now
		}
	    
}

```

Before using GiveItem remember to add all your items to your Database Blueprint so the array is valid

By the end of the tutorial you should have someting similar to this

[![](http://tinypic.com/images/goodbye.jpg) ](http://tinypic.com/images/goodbye.jpg)

---

<div class="post-metadata">

**Author:** ![anonymous\_user\_a2b6dbaa](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@anonymous\_user\_a2b6dbaa](https://forums.unrealengine.com/u/anonymous_user_a2b6dbaa)\
**Post date:** [May 21, 2014, 2:57pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/6 "2014-05-21T14:57:31Z")

</div>

Thank you very much it’s really helpful ! I have been working on my own Inventory and I was stuck on the 3DMesh part.

When it all works well I will share, it might interest some people.

---

<div class="post-metadata">

**Author:** ![pc-jose](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pc-jose](https://forums.unrealengine.com/u/pc-jose)\
**Post date:** [May 29, 2014, 6:52pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/7 "2014-05-29T18:52:37Z")

</div>

#include “Prooject.h”  
#include “Database.h”  
#include “ProojectGameMode.h”

Prooject.h, what is this, please?  
Thank you

---

<div class="post-metadata">

**Author:** ![alvarofer0020](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@alvarofer0020](https://forums.unrealengine.com/u/alvarofer0020)\
**Post date:** [May 29, 2014, 7:55pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/8 "2014-05-29T19:55:02Z")

</div>

These should be changed to your gamemode and UProject i.e MyProject, MyProjectGamemode

Im actually going to give the whole thing a big overhaul as well with the use of DataTables

---

<div class="post-metadata">

**Author:** ![pc-jose](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pc-jose](https://forums.unrealengine.com/u/pc-jose)\
**Post date:** [May 29, 2014, 8:38pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/9 "2014-05-29T20:38:13Z")

</div>

Thank you very much…really hepful.

---

<div class="post-metadata">

**Author:** ![pc-jose](https://d3kjluh73b9h9o.cloudfront.net/original/4X/2/8/5/28502927f1d97ba1051b3b47ccfe17233bf41ef0.png) [@pc-jose](https://forums.unrealengine.com/u/pc-jose)\
**Post date:** [May 29, 2014, 9:05pm UTC](https://forums.unrealengine.com/t/tutorial-basic-inventory-item-system/2952/10 "2014-05-29T21:05:37Z")

</div>

Excuse me again 🙂 I have seen you have got three Blueprints: BP\_DB, BP\_Item, and TestItemStructure, could you be so kind to explain relations beetween those BPs and your diferent class? Database class is the parent class for BP\_DB? How to pass de BP\_Item to BP\_DB? Thank you for your consideration.  
Other Question about this thread: [A new, community-hosted Unreal Engine Wiki - Announcements and Releases - Unreal Engine Forums](https://wiki.unrealengine.com/Basic_Inventory_/_Item_system)

TArray\<class ABasicItem\*\> AProojectCharacter::GetCurrentInventory()  
{  
return ItemInventory;  
}

TArray\<class ABasicItem\*\> ?? You definition is TArray\<class AProojectItem\*\> GetCurrentInventory();

Then, i have to change for this code??

TArray\<class AProojectItem\*\> AProojectCharacter::GetCurrentInventory()  
{  
return ItemInventory;  
}