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Posted by on Jun 17, 2014

Spawn Different Pawns Depending on Player Selection

Spawn Different Pawns Depending on Player Selection

Two tutorials in a week! I’ve had a backlog list of tutorials I’d like to write so I’m trying to catch back up before I start into the next milestone for our first UE4 game. This time I’m covering how to spawn different pawns for each player connected to the game. Not every player is likely going to use DefaultPawnClass as their Pawn and my quick search through the UE4 community didn’t result in any information. The Shooter example touches on this but only handles the difference between AI and Player, and not what to do if you have multiple Pawns that a player can select.

The first question I had when starting into this was where to store the information that tells the server what player is using what Pawn. I think the reason I struggled with this for so long was simply because the class that really holds information about a player is named APlayerController and that led me to believe that I really should only be using it for input from the player. So very very wrong. The APlayerController class is perfectly suited for this usage.

So the first thing I did was create a new struct to hold information about the players chosen Pawn. In the example below I only have one int32 as a property, but in our actual code we’re storing much more about the Pawn that is required at spawn such as items the player may have equipped. For the purposes of this tutorial though the below is enough.

struct PlayerPawnData
{
	int32 Type;
};

Then inside your custom APlayerController declaration you’d want to define a public property that uses this struct as it’s type.

PlayerPawnData CurrentPawnData;

With this data now available in your APlayerController declaration lets move to the custom AGameMode you’ve defined for your UE4 game.

There are a few functions inside AGameMode that are important to respawning a player. The first is RestartPlayer and the name of this function should make it’s use pretty self-explanatory. This function is called when a player spawns, whether it’s when they’ve first joined or just died. The functions that are called inside RestartPlayer is what we’re going to focus on, primarily GetDefaultPawnClassForController.

The basic functionality of GetDefaultPawnClassForController simply returns the member variable DefaultPawnClass but for this game that isn’t going to work since each player could have a different Pawn class. That means we’re going to have to override this function entirely. Lets start with the declaration inside your custom AGameMode class.

virtual UClass* GetDefaultPawnClassForController(AController* InController) OVERRIDE;

We’ll also need some sort of storage so we can reference the Pawn class using the type provided inside the PlayerPawnData variable on the APlayerController.

TMapBase<int32, UClass*, false> PawnTypes;

So we’ve marked GetDefaultPawnClassForController as an override and we have a place to store our pawn types now lets create the functionality. Same as the examples above I’ve simplified the code for this tutorial. We’ve got a little more going on inside our GetDefaultPawnClassForController.

UClass* AMyGameMode::GetDefaultPawnClassForController(AController* InController)
{
	AMyPlayerController* PlayerController = Cast<AMyPlayerController>(InController);

	UClass* PawnClass = PawnTypes.Find(PlayerController->CurrentPawnData.Type);

	return PawnClass;
}

So what’s happening above? We’re casting the incoming AController into our custom APlayerController and then referencing the CurrentPawnData’s property Type to find the correct Pawn to spawn. With just this overridden the UE4 base AGameMode class will start spawning the correct Pawn when the player joins or dies.

I’m sure there’s a different way to go about doing this but this felt right to me. Storing the actual UClass would be an option but because in our specific use case we’re storing more than just the UClass to spawn but also base stats pertaining to that Pawn type I went with just storing the type.