LOD

Source/MasterTestProject/Tileset.cpp

@@ -8,23 +8,144 @@
 #include "Tileset.h"
 
 
+ATilesetActor::ATilesetActor(const FObjectInitializer& ObjectInitializer) {
+
+	PrimaryActorTick.bCanEverTick = true;
+	PrimaryActorTick.bStartWithTickEnabled = true;
+	PrimaryActorTick.bAllowTickOnDedicatedServer = true;
+
+}
+
 void ATilesetActor::BeginPlay()
 {
 	Super::BeginPlay();
 
+	//RootComponent = CreateDefaultSubobject<UStaticMeshComponent>("TESTMesh");
+
 	rootTileset = new FTileContent();
 	rootTileset->url = relativeURL;
 
 	UTileDownloader *downloader = NewObject<UTileDownloader>(UTileDownloader::StaticClass());
 	downloader->GetTileContent(this, rootTileset, host);
+
 }
 
 void ATilesetActor::Tick(float DeltaSeconds)
 {
+	Super::Tick(DeltaSeconds);
+
+	UWorld* const World = GetWorld();
+	if (World && GEngine && GEngine->GameViewport //game init
+		&& rootTileset && rootTileset->tileset) // tilset loaded
+	{
+		// viewport Cam pos and FOV
+		APlayerController* Controller = World->GetFirstPlayerController();
+		FVector CamLocation = Controller->PlayerCameraManager->GetCameraLocation();
+		float FOV = Controller->PlayerCameraManager->GetFOVAngle();
+		FVector2D ViewportSize = FVector2D(1, 1);
+		GEngine->GameViewport->GetViewportSize(ViewportSize);
+
+		double lambda = ViewportSize.X / FOV;
+
+		
+		FTile *tile = &rootTileset->tileset->root;
+
+		//FVector ActorPos = FTransform(*tile->getAbsoluteTransform()).GetTranslation();
+		//double dist = (CamLocation - ActorPos).Size();
+		//
+		////SSE http://folk.uio.no/inftt/Div/visualization2.pdf
+		//double ScreenSpaceError1 = lambda * tile->geometricError / dist;
+
+		updateScreenSpaceError(tile, 0, lambda, CamLocation);
+
+
+
+		//SSE2 https://wiki.delphigl.com/index.php/Screenspace_Error
+		double maxPixelError = 30.0f;
+		double T = maxPixelError / ViewportSize.X;
+		double C = FOV / T;
+		double SSE2 = tile->geometricError * C;
+
+
+		//UE_LOG(TILES, Error, TEXT("SSError= %f,SSE2= %f, GeoError = %f, Dist %f"), ScreenSpaceError1, SSE2, tile.geometricError, dist);
+
+	}
+
+}
+
+double FTile::getScreenSpaceError(double lambda, FVector CamLocation)
+{
+	FVector ActorPos = FTransform(*this->getAbsoluteTransform()).GetTranslation();
+	double dist = (CamLocation - ActorPos).Size();
+
+	//SSE http://folk.uio.no/inftt/Div/visualization2.pdf
+	return lambda * this->geometricError / dist;
+}
+
+void FTile::setVisible(bool visible)
+{
+	if (content.tiles.Num() == 0 && !content.tileset) {
+		if (visible) {
+			//load
+		}
+
+		//maybe set parent visible untill loaded?
+	}
+	else if(content.tiles.Num() > 0) {
+		for (AProceduralEntity* object : content.tiles) {
+			object->setActorDisabled(!visible);
+		}
+	}
+}
+
+
+void ATilesetActor::updateScreenSpaceError(FTile* current, double currentSSE, double constant, FVector CamLocation)
+{
+
+	double ScreenSpaceError1 = current->getScreenSpaceError(constant, CamLocation);
+
+
+	if (ScreenSpaceError1 > LODtreshold && current->children.Num() > 0) {
+		for (FTile* child : current->children)
+		{
+			updateScreenSpaceError(child, 0, constant, CamLocation);
+		}
+
+		current->setVisible(false);
+	}
+	else {
+		current->setVisible(true);
+
+		for (FTile* child : current->children)
+		{
+			child->setVisible(false);
+		}
+
+		UE_LOG(TILES, Error, TEXT("Set Visible %s SSError= %f"), *current->content.url, ScreenSpaceError1);
+	}
+
+
+	
+
+
+	if (current->children.Num() == 0) {
+		// set visible keine 
+	}
+	else {
+		double SSEchildren = 0.0;
+		for (FTile* child : current->children)
+		{
+			SSEchildren += child->getScreenSpaceError(constant, CamLocation);
+		}
+
+		//UE_LOG(TILES, Error, TEXT("SSError= %f,SSE2 Childs= %f"), ScreenSpaceError1, SSEchildren );
+	}
 	
 
 }
 
+
+
 FTileset* ATilesetActor::parseTileset(FString JsonString, FString BaseURL)
 {
 	//TODO error Handling
@@ -96,6 +217,7 @@ void ATilesetActor::parseBatched3DTile(const TArray<uint8> data, FTile * tile)
 
 		gltf->loadModel(&data.GetData()[GLTFstart], (data.Num() - GLTFstart));
 		tile->content.tiles.Add(gltf);
+		tile->setVisible(false);
 	}
 }
 
@@ -169,6 +291,7 @@ void ATilesetActor::parseInstanced3DTile(const TArray<uint8> data, FTile * tile)
 
 		}
 	}
+	tile->setVisible(false);
 }
 
 void ATilesetActor::parse3DTile(const TArray<uint8> data, FTile *tile)
@@ -188,7 +311,6 @@ void ATilesetActor::parse3DTile(const TArray<uint8> data, FTile *tile)
 
 
 
-
 FMatrix * FTile::getMatrix()
 {
 	if (realtiveTransform == nullptr) {
@@ -215,6 +337,7 @@ FMatrix * FTile::getMatrix()
 
 FMatrix * FTile::getAbsoluteTransform()
 {
+	if (!absoluteTransform) {
 		FMatrix(absoluteTrans);
 		absoluteTrans.SetIdentity();
 		for (FTile *current = this; current != nullptr; current = current->parent) {
@@ -225,5 +348,9 @@ FMatrix * FTile::getAbsoluteTransform()
 			absoluteTrans = *this->parentTilset->parent->getAbsoluteTransform() * absoluteTrans;
 		}
 
-	return new FMatrix(absoluteTrans);
+		absoluteTransform = new FMatrix(absoluteTrans);
+	}
+
+	return absoluteTransform;
 }
+

Source/MasterTestProject/Tileset.h

@@ -90,6 +90,7 @@ struct FTileContent
 	UPROPERTY()
 		FString url;
 
+	//bool loadingStarted;
 	TArray<uint8> content;
 	struct FTileset *tileset;
 	TArray<class AProceduralEntity*> tiles;
@@ -132,18 +133,26 @@ struct FTile
 	struct FTileset *parentTilset;
 	struct FTile *parent;
 	FMatrix *realtiveTransform;
+	FMatrix *absoluteTransform;
 
 	FMatrix *getMatrix();
 	FMatrix *getAbsoluteTransform();
 
+	double getScreenSpaceError(double lambda, FVector CamLocation);
+	void setVisible(bool visible);
+
+
 	FTile() {
 		float transformDefault[] = { 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0, 0.0, 0.0, 0.0, 0.0, 1.0 };
 		transform.Empty();
 		parentTilset = nullptr;
 		parent = nullptr;
 		realtiveTransform = nullptr;
+		absoluteTransform = nullptr;
 		//transform.Append(transformDefault, 16);
 	}
+
+
 };
 
 USTRUCT()
@@ -282,12 +291,18 @@ class MASTERTESTPROJECT_API ATilesetActor : public AActor
 	GENERATED_BODY()
 
 public:
+
+	ATilesetActor(const FObjectInitializer& ObjectInitializer);
+
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Generation")
 	FString host;
 
 	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "Generation")
 	FString relativeURL;
 
+	UPROPERTY(EditAnywhere, BlueprintReadWrite, Category = "LOD")
+	float LODtreshold = 0.1;
+
 	// Called when the game starts or when spawned
 	virtual void BeginPlay() override;
 
@@ -297,6 +312,10 @@ public:
 	FTileset* parseTileset(FString JsonString, FString BaseURL);
 	void parse3DTile(const TArray<uint8> data, FTile *tile);
 
+	//virtual bool ShouldTickIfViewportsOnly() override { return true; }
+
+	void updateScreenSpaceError(FTile* current, double currentSSE, double constant, FVector CamLocation);
+
 private:
 	FTileContent *rootTileset;
 

Source/MasterTestProject/ue4-assimp/ProceduralEntity.cpp

@@ -305,6 +305,13 @@ AProceduralEntity* AProceduralEntity::clone(const FVector position)
 
 }
 
+void AProceduralEntity::setActorDisabled(bool disabled)
+{
+	this->SetActorHiddenInGame(disabled);
+	this->SetActorEnableCollision(!disabled);
+	this->SetActorTickEnabled(!disabled);
+}
+
 UMaterialInterface  *AProceduralEntity::GetMaterialForIndex(unsigned int index, const aiScene* scene){
 	if (MaterialMap.Contains(index)) {
 		return *MaterialMap.Find(index);

Source/MasterTestProject/ue4-assimp/ProceduralEntity.h

@@ -58,6 +58,8 @@ public:
 
 	AProceduralEntity* clone(FVector position);
 
+	void setActorDisabled(bool disabled);
+
 
 
 private: