Instanced Compoenent with instances only visible in scene if VisibleAnywhere used

Development Programming & Scripting
1

I have a InstancedStaticMesh component that is populated during PostInitializedComponenets()… I also check for a couple of changed properties via the PostEditPropertyChanged().

My issue is, the instances show up in the right details panel, and it bogs down the system for a little bit when selecting the actor in the outliner. I tried removing VisibleAnywhere from the InstancedStaticMesh component (it is a UPROPERTY in the class) and then the instances not only disappear in the details panel, but also in the editor scene view.

Is this expected behavior? (btw i know that the addinstance code is still being called because of prints)

code follows:

UCLASS()
class BOTBATTLE_API AHexGrid : public AActor
    {
    GENERATED_UCLASS_BODY()

	private:
		void PositionTiles();

    public:
        static FVector GetHexPosition(int32 x, int32 y, float cornerRadius);
		static EFacing::Type GetReverseFacing(EFacing::Type facing);
		static EFacing::Type GetLeftFacing(EFacing::Type facing);
		static EFacing::Type GetRightFacing(EFacing::Type facing);
		
		void PostInitializeComponents() override;
		void PostEditChangeProperty(FPropertyChangedEvent & PropertyChangedEvent) override;

		UFUNCTION(BlueprintCallable, BlueprintPure, Category = Function)
		static FRotator RotationFromFacing(EFacing::Type facing);

		UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Object)
		int32 maxQ;

		UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Object)
		int32 maxR;

		UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Object)
		EGridShape gridShape;

		UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = Object)
		TArray<ULevelFilter*> levelFilters;

		TMap<FHex, EHexType> HexGrid;

		UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Hex Tile Instanced Mesh")
		UInstancedStaticMeshComponent* InstancedFloorTile;
		UPROPERTY(BlueprintReadWrite, Category = "Hex Tile Instanced Mesh")
		UStaticMesh* SMAsset_Floor;

		UPROPERTY(BlueprintReadWrite, VisibleAnywhere, Category = "Hex Tile Instanced Mesh")
		UInstancedStaticMeshComponent* InstancedWallTile;
		UPROPERTY(BlueprintReadWrite, Category = "Hex Tile Instanced Mesh")
		UStaticMesh* SMAsset_Wall;

		virtual void BeginPlay() override; 
		bool GetColumnAndRow(AHexTile *hex, int32 *column, int32 *row);
        AHexTile *GetAdjacentHex(AHexTile *hex, EFacing::Type facing);
		
		virtual void OnConstruction(const FTransform& Transform) override;


    };

AHexGrid::AHexGrid(const class FPostConstructInitializeProperties& PCIP)
	: Super(PCIP)
	{
	//Mesh
	static ConstructorHelpers::FObjectFinder<UStaticMesh> floorTileMesh((TEXT("StaticMesh'/Game/Meshes/hextile.HexTile'")));
	SMAsset_Floor = floorTileMesh.Object;

	//create new object
	InstancedFloorTile = PCIP.CreateDefaultSubobject<UInstancedStaticMeshComponent>(this, TEXT("InstancedFloorTile"));
	
	//Not Made some reason?
	if (!InstancedFloorTile) return;
	
	InstancedFloorTile->AttachTo(RootComponent);

	//Set to Asset
	InstancedFloorTile->SetStaticMesh(SMAsset_Floor);

	InstancedFloorTile->bOwnerNoSee = false;
	InstancedFloorTile->bCastDynamicShadow = false;
	InstancedFloorTile->CastShadow = false;
	
	//Visibility
	InstancedFloorTile->SetHiddenInGame(false);

	////Mobility
	InstancedFloorTile->SetMobility(EComponentMobility::Static);

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

	////~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

	//Mesh
	static ConstructorHelpers::FObjectFinder<UStaticMesh> wallTileMesh((TEXT("StaticMesh'/Game/Meshes/hex_wall.hex_wall'")));
	SMAsset_Wall = wallTileMesh.Object;

	//create new object
	InstancedWallTile = PCIP.CreateDefaultSubobject<UInstancedStaticMeshComponent>(this, TEXT("InstancedWallTile"));

	//Not Made some reason?
	if (!InstancedWallTile) return;

	InstancedWallTile->AttachTo(RootComponent);

	//Set to Asset
	InstancedWallTile->SetStaticMesh(SMAsset_Floor);

	InstancedWallTile->bOwnerNoSee = false;
	InstancedWallTile->bCastDynamicShadow = false;
	InstancedWallTile->CastShadow = false;

	//Visibility
	InstancedWallTile->SetHiddenInGame(false);

	////Mobility
	InstancedWallTile->SetMobility(EComponentMobility::Static);

	//Collision
	InstancedWallTile->BodyInstance.SetCollisionEnabled(ECollisionEnabled::QueryOnly);
	InstancedWallTile->BodyInstance.SetObjectType(ECC_WorldStatic);
	InstancedWallTile->BodyInstance.SetResponseToAllChannels(ECR_Ignore);
	InstancedWallTile->BodyInstance.SetResponseToChannel(ECC_WorldStatic, ECR_Block);
	InstancedWallTile->BodyInstance.SetResponseToChannel(ECC_WorldDynamic, ECR_Block);
	}

void AHexGrid::OnConstruction(const FTransform& Transform) {
	
}

void AHexGrid::PostInitializeComponents() 
	{
	Super::PostInitializeComponents();
	HexGrid.Reset();
	InstancedFloorTile->ClearInstances();
	this->PositionTiles();
	}

#if WITH_EDITOR  
void AHexGrid::PostEditChangeProperty(FPropertyChangedEvent & PropertyChangedEvent)
	{
	//Get the name of the property that was changed  
	FName PropertyName = (PropertyChangedEvent.Property != nullptr) ? PropertyChangedEvent.Property->GetFName() : NAME_None;

	// We test using GET_MEMBER_NAME_CHECKED so that if someone changes the property name  
	// in the future this will fail to compile and we can update it.  
	if (PropertyName == GET_MEMBER_NAME_CHECKED(AHexGrid, gridShape) ||
		PropertyName == GET_MEMBER_NAME_CHECKED(AHexGrid, maxQ) ||
		PropertyName == GET_MEMBER_NAME_CHECKED(AHexGrid, maxR))
		{
		HexGrid.Reset();
		InstancedFloorTile->ClearInstances();
		this->PositionTiles();
		}

	// Call the base class version  
	Super::PostEditChangeProperty(PropertyChangedEvent);
	}
#endif
2

Hey joessu-

Are you creating the InstancedStaticMesh as a component to an actor or are you referring to a new class based on the InstancedStaticMesh Component class? Can you post the code relating to the InstancedStaticMesh Component and how it is being implemented?

Cheers

3

The InstancedStaticMesh component is the child of an actor. I can post the code as soon as I get a chance.

4

updated question with code

5

Hey joessu-

I tried a simple setup to match what you have with an instanced static mesh component and a static mesh as follows:

static ConstructorHelpers::FObjectFinderTestMesh(TEXT("StaticMesh'/Game/StarterContent/Shapes/Shape_Cube.Shape_Cube'"));
    	MyStaticMesh = TestMesh.Object;
    
    	InstancedMesh = CreateDefaultSubobject<UInstancedStaticMeshComponent>(TEXT("something"));
    	InstancedMesh->AttachTo(RootComponent);
    
    	InstancedMesh->SetStaticMesh(MyStaticMesh);

With both the UStaticMesh and UInstancedStaticMeshComponent set to VisibleAnywhere I did not actually see the actor that I added to the level. If I changed the UInstancedStaticMeshComponent to a UStaticMeshComponent (removed Instanced) then it became visible in the level. Can you confirm them in a new project or provide additional steps if I’m missing something in my setup?

6

Hey ,

Thanks for looking into this. Are you adding instances to the instanced static mesh? i didnt post the PositionTiles function but it calls InstancedFloorTile->AddInstance(FTransform(pos));

7

I have a blueprint based on the class above. Perhaps that is my issue?

8

Adding the AddInstance(FTransform()) call allowed the static mesh to show in the editor. When I then removed the VisibleAnywhere specifier the mesh was still visible in the viewport. When I closed and reopened the project the mesh was missing from the blueprint I created based on the class however it appeared again if I added an instance to the level or opened the blueprint for editing. Are you using instances of the class itself or do you have a blueprint based on the class that you’re using?

9

Hey joessu-

I tried to reproduce this again by copying the code that you posted. I copied lines 35 - 39 of your header to add to my own as well as 58 - 87 (inside your constructor). After creating a blueprint based on my class and adding an instance of the blueprint to the scene I added 2 elements to the Instance array in the details panel. In the code I then removed the VisiableAnywhere specifier and compiled. After the hot reload the mesh was still visible in my level. If possible please test this in a new project and let me know if you have the same result. If you do have a different outcome please list the steps you took that caused the mesh to disappear.

10

Hey joessu-

I will be marking this post as resolved for tracking purposes. If you are still having issues with instanced components not being visible feel free to add a comment to reopen the post and we will continue investigating.

Cheers

11

I stopped using visiableanywhere with them and after figuring out how AddInstance and RemoveInstance works, we have no issues anymore. (granted we are avoiding VisibleAnywhere)