How to get collision primitive name involved in collision?

3dRaven · May 28, 2025, 1:13pm

CoreBlueprintFunctionLibrary.h

#pragma once

#include "CoreMinimal.h"
#include "Kismet/BlueprintFunctionLibrary.h"
#include "CoreBlueprintFunctionLibrary.generated.h"

UCLASS()
class YOURGAME_API UCoreBlueprintFunctionLibrary : public UBlueprintFunctionLibrary
{
	GENERATED_BODY()
	
	UFUNCTION(BlueprintCallable)
	static FString GetCollisionName(UPrimitiveComponent* OtherComp, FHitResult HitResult);
};

CoreBlueprintFunctionLibrary.cpp

#include "CoreBlueprintFunctionLibrary.h"
#include "Engine/HitResult.h"
#include "PhysicsEngine/BodySetup.h"

FString UCoreBlueprintFunctionLibrary::GetCollisionName(UPrimitiveComponent* OtherComp, FHitResult HitResult)
{
	if (HitResult.ElementIndex == -1) HitResult.ElementIndex = 0;

	FString foundName = "";
	if (OtherComp != nullptr && HitResult.ElementIndex > -1)
	{

		if (UStaticMeshComponent* mesh = Cast<UStaticMeshComponent>(OtherComp))
		{
			FKShapeElem* el = mesh->GetStaticMesh()->GetBodySetup()->AggGeom.GetElement(HitResult.ElementIndex);
			GEngine->AddOnScreenDebugMessage(-1, 1, FColor::Cyan, *el->GetName().ToString());
			foundName = el->GetName().ToString();
		}

		else if (UStaticMesh* mesh2 = Cast<UStaticMesh>(OtherComp))
		{
			FKShapeElem* el = mesh2->GetBodySetup()->AggGeom.GetElement(HitResult.ElementIndex);
			GEngine->AddOnScreenDebugMessage(-1, 1, FColor::Cyan, *el->GetName().ToString());
			foundName = el->GetName().ToString();
		}
	}

	return foundName;
}