[Suggestion] Access Violation

[majule]

This might be a good place in the course to talk about the dreaded access violation error / crash. In this case, I messed up the if statement and so when I got to the HitActor->GetActorNameOrLabel() part, it tried to access the name from a null reference (when HasHit is false, HitActor = null). Since this is a fairly regular occurrence, if one isn’t careful, and causes a scary crash, it might be worth a short lesson here.

[DanM]

Thanks for the suggestion. I’ve forwarded it to Sam.

[Iketh]

I’m getting this access violation every time the sweep hits.

	FCollisionShape sphere = FCollisionShape::MakeSphere(grabRadius);
	//FCollisionShape line=FCollisionShape::LineShape;
	FHitResult hitResult;
	if (GetWorld()->SweepSingleByChannel(hitResult, start, end, FQuat::Identity, ECC_GameTraceChannel2, sphere)) {
		AActor* hitActor = hitResult.GetActor();
		if (&hitActor != NULL) { UE_LOG(LogTemp, Display, TEXT("Object Hit: %s"), *hitActor->GetActorNameOrLabel()); }
	} else {
		UE_LOG(LogTemp, Display, TEXT("Object Hit: none"));
	}

[DanM]

if (&hitActor != NULL) 
{ 
    UE_LOG(LogTemp, Display, TEXT("Object Hit: %s"), *hitActor->GetActorNameOrLabel()); 
}

This is always true as you’re checking the address of the variable that’s on the stack and not what the address that’s stored in the pointer. (remove the &)

[Iketh]

whoops thanks that worked

when it’s not printing anything, it’s difficult to figure out what it’s hitting… im not using the crypt raider pack, im using megascans and geometry