SetVectorParameterValue crashing the editor during compilation

Development Programming & Scripting
1

Hello,

I’m trying to spawn decals under my characters as team markers. The decals are correctly spawned with C++ using default values, however the compilation instantly crashes the editor when I attempt to modify the VectorParameterValue (same with scalar parameters.)

191647-teammarker.png
191647-teammarker.png748×485 78.3 KB

As for my code :
.h

public:
	ACharacterUnit();

	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = CharacterTeamMarker)
		bool bCharacterTeam1;

private:
	UPROPERTY()
	class UMaterialInstanceDynamic* TeamMarkerDynamic;

	UPROPERTY()
	FLinearColor TeamMarkerColor;

.cpp

ACharacterUnit::ACharacterUnit() {
	static ConstructorHelpers::FObjectFinder<UMaterial> TeamMarkerMaterial(TEXT("Material'/Game/CharacterUnit/TeamMarker/MAT_TeamMarker.MAT_TeamMarker'"));
	if (TeamMarkerMaterial.Object)
	{
		TeamMarkerDynamic = (UMaterialInstanceDynamic*) (TeamMarkerMaterial.Object);
		/*Crashes here*/TeamMarkerDynamic->SetVectorParameterValue(FName("TeamMarkerColor"), FLinearColor(100.f, 0.f, 0.f));

	}
}

void ACharacterUnit::BeginPlay() {
	Super::BeginPlay();
	UGameplayStatics::SpawnDecalAttached(TeamMarkerDynamic, FVector(100.0f, 100.0f, 100.0f), GetRootComponent(),FName(""), GetActorLocation(), FRotator(-90.f, -90.f, 0.f), EAttachLocation::Type(1));
}
2

Thank you (a LOT,) that’s the correct approach and I got it working.

I just want to add that according to this post, NULL should be used instead of this. (“this” causes a compilation crash when the function is called in recent engine versions.)

3

I think you forgot to create your MID first with create like this:

MaterialInstance = UMaterialInstanceDynamic::Create(Material, NULL);

so in your case it should be:

TeamMarkerDynamic = UMaterialInstanceDynamic::Create(TeamMarkerMaterial.Object, NULL);

TeamMarkerDynamic->SetVectorParameterValue(FName("TeamMarkerColor"), FLinearColor(100.f, 0.f, 0.f));

I’m 90% sure you can’t use a cast like you are trying now. Would be great to hear if it’s working with my solution. <3

4

You are right, I made an edit! <3