Unable to assign material to InstancedStaticMeshComponent

Development Rendering
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1

I have been unable to get a material on an InstancedStaticMeshComponent, and unable to find any code examples on the forums or AnswerHub showing how it might be done. I have tested my code by putting in both a StaticMeshComponent and an InstancedStaticMeshComponent. The material applies to the SMC, but not the ISMC. I’m sure there’s something obvious I’m missing. Please advise.

Block.cpp

AArchBlock::AArchBlock(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
{
	PrimaryActorTick.bCanEverTick = true;

	// capsule component for root
	CapsuleComponent = PCIP.CreateDefaultSubobject<UCapsuleComponent>(this, "MyCapsuleComponent");
	CapsuleComponent->InitCapsuleSize(100.0f, 200.0f);
	CapsuleComponent->BodyInstance.bEnableCollision_DEPRECATED = true;
	static FName CollisionProfileName(TEXT("Pawn"));
	CapsuleComponent->SetCollisionProfileName(CollisionProfileName);
	
	RootComponent = CapsuleComponent;

	//-----------------------------------------------------------------------

	// staticmeshcomponent, called blockstaticmeshcomponent here
	static ConstructorHelpers::FObjectFinder<UStaticMesh> StaticMeshFinder(TEXT("StaticMesh'/Game/Shapes/Shape_Cube.Shape_Cube'"));	
	AssetSM_BlockStaticMesh = StaticMeshFinder.Object;

	BlockStaticMeshComponent = PCIP.CreateDefaultSubobject < UStaticMeshComponent >(this, TEXT("BlockStaticMeshComponent"));
	BlockStaticMeshComponent->SetStaticMesh(AssetSM_BlockStaticMesh);

	SetupSMComponentsWithCollision(BlockStaticMeshComponent);
	BlockStaticMeshComponent->AttachParent = CapsuleComponent;

	BlockStaticMeshComponent->SetMobility(EComponentMobility::Movable);

	BlockStaticMeshComponent->BodyInstance.SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	BlockStaticMeshComponent->BodyInstance.SetObjectType(ECC_WorldDynamic);
	BlockStaticMeshComponent->BodyInstance.SetResponseToAllChannels(ECR_Ignore);
	BlockStaticMeshComponent->BodyInstance.SetResponseToChannel(ECC_WorldStatic, ECR_Block);
	BlockStaticMeshComponent->BodyInstance.SetResponseToChannel(ECC_WorldDynamic, ECR_Block);

	//-----------------------------------------------------------------------

	// instancedstaticmeshcomponent
	static ConstructorHelpers::FObjectFinder<UStaticMesh> StaticMeshOb(TEXT("StaticMesh'/Game/Shapes/Shape_Cube.Shape_Cube'"));
	SMAsset_Cube = StaticMeshOb.Object;

	InstancedStaticMeshComponent = PCIP.CreateDefaultSubobject<UInstancedStaticMeshComponent>(this, TEXT("InstancedStaticMeshComponentCOMP"));
	InstancedStaticMeshComponent->AttachParent = RootComponent;

	InstancedStaticMeshComponent->SetStaticMesh(SMAsset_Cube);

	InstancedStaticMeshComponent->bOwnerNoSee = false;
	InstancedStaticMeshComponent->bCastDynamicShadow = false;
	InstancedStaticMeshComponent->CastShadow = false;
	InstancedStaticMeshComponent->BodyInstance.SetObjectType(ECC_WorldDynamic);

	InstancedStaticMeshComponent->SetHiddenInGame(false);

	InstancedStaticMeshComponent->SetMobility(EComponentMobility::Movable);

	InstancedStaticMeshComponent->BodyInstance.SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	InstancedStaticMeshComponent->BodyInstance.SetObjectType(ECC_WorldDynamic);
	InstancedStaticMeshComponent->BodyInstance.SetResponseToAllChannels(ECR_Ignore);
	InstancedStaticMeshComponent->BodyInstance.SetResponseToChannel(ECC_WorldStatic, ECR_Block);
	InstancedStaticMeshComponent->BodyInstance.SetResponseToChannel(ECC_WorldDynamic, ECR_Block);

	//-----------------------------------------------------------------------

	// find and apply materials
	static ConstructorHelpers::FObjectFinder <UMaterial>MaterialFinder(TEXT("Material'/Game/Materials/M_Brick_Clay_Beveled.M_Brick_Clay_Beveled'")); 
	if (MaterialFinder.Object != NULL)
	{
		MyMaterial = (UMaterial*)MaterialFinder.Object;
	}
	MyMaterialDynamic = UMaterialInstanceDynamic::Create(MyMaterial, this);
	InstancedStaticMeshComponent->SetMaterial(0, MyMaterialDynamic);
	BlockStaticMeshComponent->SetMaterial(0, MyMaterialDynamic);
}

And Block.h

UCLASS()
class ARCH_API AArchBlock : public AActor
{
	GENERATED_UCLASS_BODY()

	UPROPERTY()
	TSubobjectPtr<UInstancedStaticMeshComponent> InstancedStaticMeshComponent;

	UPROPERTY()
		UStaticMesh* SMAsset_Cube;

	TSubobjectPtr<UStaticMeshComponent> BlockStaticMeshComponent;
	UStaticMesh * AssetSM_BlockStaticMesh;

	TSubobjectPtr<UCapsuleComponent> CapsuleComponent;

	UMaterial* MyMaterial;
	UMaterialInstanceDynamic* MyMaterialDynamic;
}

And the code from which it the spawning is called

	FActorSpawnParameters MySpawnParams;
	MySpawnParams.bNoCollisionFail = true;

	AArchBlock* NewBlock = GetWorld()->SpawnActor<AArchBlock>(AArchBlock::StaticClass(), FVector(0, 0, 0), FRotator(0, 0, 0), MySpawnParams);

	FTransform newT = NewBlock->GetTransform();
	newT.SetLocation(FVector(-300, -300, -300));
	NewBlock->InstancedStaticMeshComponent->AddInstance(newT);

	newT.SetLocation(FVector(300, 300, 300));
	NewBlock->InstancedStaticMeshComponent->AddInstance(newT);
2

Aha!

Materials have an attribute:
bUsedWithInstancedStaticMeshes

Toggle that to TRUE and it works.

3

The same thing applies to many other types of meshes. We had the same issue with SplineMeshComponent not being able to recieve materials in runtime; turns out it’s a bool you need to enable in the material. Thank you :slight_smile: