FadeObjects — Скрываем объекты между камерой и персонажем

USTRUCT()
struct FFadeObjStruct
{
	GENERATED_USTRUCT_BODY()
 
	UPROPERTY()
	UPrimitiveComponent* primitiveComp;
 
	UPROPERTY()
	TArray<UMaterialInterface*> baseMatInterface;
 
	UPROPERTY()
	TArray<UMaterialInstanceDynamic*> fadeMID;
 
	UPROPERTY()
	float fadeCurrent;
 
	UPROPERTY()
	bool bToHide;
 
	void NewElement(UPrimitiveComponent* newComponent, TArray<UMaterialInterface*> newBaseMat, <UMaterialInstanceDynamic*> newMID, float currentFade, bool bHide)
	{
    	primitiveComp = newComponent;
    	baseMatInterface = newBaseMat;
    	fadeMID = newMID;
    	fadeCurrent = currentFade;
    	bToHide = bHide;
	}
 
	void SetHideOnly(bool hide)
	{
    	bToHide = hide;
	}
 
	void SetFadeAndHide(float newFade, bool newHide)
	{
    	fadeCurrent = newFade;
    	bToHide = newHide;
	}
 
	//For Destroy
	void Destroy()
	{
    	primitiveComp = nullptr;
	}
 
	//Constructor
	FFadeObjStruct()
	{
    	primitiveComp = nullptr;
    	fadeCurrent = 0;
    	bToHide = true;
	}
};

void USFadeObjectsComponent::AddObjectsToHide()
{
	UGameplayStatics::GetAllActorsOfClass(this, playerClass, characterArray);

	for (AActor* currentActor : characterArray)
	{
		const FVector traceStart = GEngine->GetFirstLocalPlayerController(GetWorld())->PlayerCameraManager->GetCameraLocation();
		const FVector traceEnd = currentActor->GetActorLocation();
		const FRotator traceRot = currentActor->GetActorRotation();
		FVector traceLentgh = traceStart - traceEnd;
		const FQuat acQuat = currentActor->GetActorQuat();

		if (traceLentgh.Size() < workDistance)
		{
			FCollisionQueryParams traceParams(TEXT("FadeObjectsTrace"), true, GetOwner());

			traceParams.AddIgnoredActors(actorsIgnore);
			traceParams.bTraceAsyncScene = true;
			traceParams.bReturnPhysicalMaterial = false;
			// Not tracing complex uses the rough collision instead making tiny objects easier to select.
			traceParams.bTraceComplex = false;

			TArray<FHitResult> hitArray;
			TArray<TEnumAsByte<EObjectTypeQuery>> traceObjectTypes;

			// Convert ECollisionChannel to ObjectType
			for (int i = 0; i < objectTypes.Num(); ++i)
			{
				traceObjectTypes.Add(UEngineTypes::ConvertToObjectType(objectTypes[i].GetValue()));
			}

			// Check distance between camera and player for new object to fade, and add this in array
			GetWorld()->SweepMultiByObjectType(hitArray, traceStart, traceEnd, acQuat, traceObjectTypes,
				FCollisionShape::MakeCapsule(capsuleRadius, capsuleHalfHeight), traceParams);

			for (int hA = 0; hA < hitArray.Num(); ++hA)
			{
				if (hitArray[hA].bBlockingHit && IsValid(hitArray[hA].GetComponent()) && !fadeObjectsHit.Contains(hitArray[hA].GetComponent()))
				{
					fadeObjectsHit.AddUnique(hitArray[hA].GetComponent());
				}
			}
		}
	}

	// Make fade array after complete GetAllActorsOfClass loop
	for (int fO = 0; fO < fadeObjectsHit.Num(); ++fO)
	{
		// If not contains this component in fadeObjectsTemp
		if (!fadeObjectsTemp.Contains(fadeObjectsHit[fO]))
		{
			TArray<UMaterialInterface*> lBaseMaterials;
			TArray<UMaterialInstanceDynamic*> lMidMaterials;

			lBaseMaterials.Empty();
			lMidMaterials.Empty();

			fadeObjectsTemp.AddUnique(fadeObjectsHit[fO]);

			// For loop all materials ID in object
			for (int nM = 0; nM < fadeObjectsHit[fO]->GetNumMaterials(); ++nM)
			{
				lMidMaterials.Add(UMaterialInstanceDynamic::Create(fadeMaterial, fadeObjectsHit[fO]));
				lBaseMaterials.Add(fadeObjectsHit[fO]->GetMaterial(nM));

				// Set new material on object
				fadeObjectsHit[fO]->SetMaterial(nM, lMidMaterials.Last());
			}
			// Create new fade object in array of objects to fade
			FFadeObjStruct newObject;
			newObject.NewElement(fadeObjectsHit[fO], lBaseMaterials, lMidMaterials, immediatelyFade, true);
			// Add object to array
			fadeObjects.Add(newObject);

			// Set collision on Primitive Component
			fadeObjectsHit[fO]->SetCollisionResponseToChannel(ECC_Camera, ECR_Ignore);
		}
	}

	// Set hide to visible true if contains
	for (int fOT = 0; fOT < fadeObjectsTemp.Num(); ++fOT)
	{
		if (!fadeObjectsHit.Contains(fadeObjectsTemp[fOT]))
		{
			fadeObjects[fOT].SetHideOnly(false);
		}
	}

	// Clear array
	fadeObjectsHit.Empty();
}

void USFadeObjectsComponent::FadeObjWorker()
{
	if (fadeObjects.Num() > 0)
	{
    	// For loop all fade objects
    	for (int i = 0; i < fadeObjects.Num(); ++i)
    	{
        	// Index of iteration
        	int fnID = i;
 
        	float adaptiveFade;
 
        	if (fnID == fadeObjects.Num())
        	{
            	adaptiveFade = nearObjectFade;
        	}
        	else
        	{
            	adaptiveFade = farObjectFade;
        	}
 
        	// For loop fadeMID array
        	for (int t = 0; t < fadeObjects[i].fadeMID.Num(); ++t)
        	{
            	float targetF;
 
            	const float currentF = fadeObjects[i].fadeCurrent;
 
            	if (fadeObjects[i].bToHide)
            	{
                	targetF = adaptiveFade;
            	}
            	else
            	{
                	targetF = 1.0f;
            	}
 
            	const float newFade = FMath::FInterpConstantTo(currentF, targetF, GetWorld()->GetDeltaSeconds(), fadeRate);
 
            	fadeObjects[i].fadeMID[t]->SetScalarParameterValue("Fade", newFade);
 
            	currentFade = newFade;
 
            	fadeObjects[i].SetFadeAndHide(newFade, fadeObjects[i].bToHide);
        	}
        	// remove index in array
        	if (currentFade == 1.0f)
        	{
            	for (int bmi = 0; bmi < fadeObjects[fnID].baseMatInterface.Num(); ++bmi)
            	{
                	fadeObjects[fnID].primitiveComp->SetMaterial(bmi, fadeObjects[fnID].baseMatInterface[bmi]);
            	}
 
            	fadeObjects[fnID].primitiveComp->SetCollisionResponseToChannel(ECC_Camera, ECR_Block);
            	fadeObjects.RemoveAt(fnID);
            	fadeObjectsTemp.RemoveAt(fnID);
        	}
    	}
	}
}