How to spawn a decal in C++?

Development Rendering
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1

How do I spawn a decal in C++?
There is a blueprint function called “SpawnDecalAtLocation” but there is no such function in C++.

2

I think you must use UDecalComponent

MyActor.cpp

#include "Components/DecalComponent.h"

AMyActor::AMyActor()
{
   Decal = CreateDefaultSubobject<UDecalComponent>(L"Decal");
   Decal->SetupAttachment(RootComponent);
}

MyActor.h

class MYPROJECT_API AMyActor : public AActor
{
	GENERATED_BODY()
	
private:

	class UDecalComponent * Decal;
};
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3

UDecalComponent is a component, which you can’t (just?) spawn in the world.
Also, calling CreateDefaultSubobject will create a subobject for the class you are calling the function in, so in my case the player controller.

4

I figured it out:

ADecalActor* decal = GetWorld()->SpawnActor<ADecalActor>(hitResult.Location, FRotator());
if (decal)
{
	decal->SetDecalMaterial(ActionDecalToSpawn);
	decal->SetLifeSpan(2.0f);
	decal->GetDecal()->DecalSize = FVector(32.0f, 64.0f, 64.0f);
	m_previousActionDecal = decal;
}
else
{
	UE_LOG(LogTemp, Warning, TEXT("No decal spawned"));
}

Note that ActionDecalToSpawn is a UMaterialInterface* (=Material).
You need to include

#include "Engine/DecalActor.h"
#include "Components/DecalComponent.h"

in the cpp file where you are spawning the decal actor.

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