Spawning an explosion effect without using a blueprint?

Development Programming & Scripting C++
1

I’m having trouble finding examples of how to spawn an explosion effect using pure c++ without the aid of a blueprint. I want to play the P_Explosion effect at an impact point. I have the coordinates, but I can’t figure out how to play the particle effect there.

2 

FHitResult Hit;
FVector SpawnLocation = Hit.ImpactPoint;
FRotator SpawnRotation = Hit.ImpactNormal.Rotation();
UParticleSystem* EmitterTemplate = your ref to P_Explosion
UGameplayStatics::SpawnEmitterAtLocation(WorldContextObject, EmitterTemplate, SpawnLocation, SpawnRotation);
1 Like
3

I tried that. However, there’s the issue of getting a reference to the template. It seems that you need a blueprint in order to get the template.

4

You should use static ConstructorHelpers::FObjectFinder to find the reference to the asset if you don’t want to expose the system and set it in blueprint.

5

and how do you get a callback to destroy the actor after the explosion is finished? you don’t want to leave this garbage there do you?

6

Yeah, you still need to tell it what template to use. You either hardcode it using FObjectFinder or StaticLoadObject (and thus have a C++ class for every different explosion you want to make) - or you use a Blueprinted version of your explosion class and set the defaults there.
@nullbot - You can tell Emitters to auto-destroy themselves when they finish.

7

make sure it loops once and destroy on finish are on :smiley:

8

C++ class for every different explosion?
I did it this way;

in .h



USTRUCT(BlueprintType)
struct WHATEVS_API FParticleEffects {
	GENERATED_USTRUCT_BODY()
public:
	FParticleEffects {}

	TArray<UParticleSystem*> aExplosions;

};
extern FParticleEffects ParticleEffects;

in .cpp



FParticleEffects ParticleEffects;

AMyClass::AMyClass(const FObjectInitializer& ObjectInitializer) {
ConstructorHelpers::FObjectFinder<UParticleSystem> PEffectQuery = TEXT("ParticleSystem'/Game/Art/ParticleEffects/SomeExplosion1'");
	ParticleEffects.aExplosions.Add(PEffectQuery.Object);
	
PEffectQuery = (TEXT("ParticleSystem'/Game/Art/ParticleEffects/SomeExplosion2'"));
	ParticleEffects.aExplosions.Add(PEffectQuery.Object);

PEffectQuery = (TEXT("ParticleSystem'/Game/Art/ParticleEffects/SomeExplosion3'"));
	ParticleEffects.aExplosions.Add(PEffectQuery.Object);

.
.
.

PEffectQuery = (TEXT("ParticleSystem'/Game/Art/ParticleEffects/SomeExplosionN'"));
	ParticleEffects.aExplosions.Add(PEffectQuery.Object);

}

This way your struct which holds all your particle effects is available to all classes which include your .h-file via the extern keyword.

UStructs can also hold functions if you’d like to for example get a random explosion emitter.

9

Interesting, different strokes I guess. I personally prefer to just abstract the class with a Blueprint and set the defaults.