ALODActor* FHierarchicalLODUtilities::CreateNewClusterFromActors(UWorld* InWorld, AWorldSettings* WorldSettings, const TArray<AActor*>& InActors, const int32 InLODLevel /*= 0*/)
{
checkf(InWorld != nullptr, TEXT("Invalid world"));
checkf(InActors.Num() > 0, TEXT("Zero number of sub actors"));
checkf(WorldSettings != nullptr, TEXT("Invalid world settings"));
checkf(WorldSettings->bEnableHierarchicalLODSystem, TEXT("Hierarchical LOD system is disabled"));
const FScopedTransaction Transaction(LOCTEXT("UndoAction_CreateNewCluster", "Create new Cluster"));
InWorld->Modify();
// Create the cluster
ALODActor* NewCluster = FHierarchicalLODUtilities::CreateNewClusterActor(InWorld, InLODLevel, WorldSettings);
checkf(NewCluster != nullptr, TEXT("Failed to create a new cluster"));
// Add InActors to new cluster
for (AActor* Actor : InActors)
{
checkf(Actor != nullptr, TEXT("Invalid actor in InActors"));
// Check if Actor is currently part of a different cluster
ALODActor* ParentActor = FHierarchicalLODUtilities::GetParentLODActor(Actor);
if (ParentActor != nullptr)
{
// If so remove it first
ParentActor->Modify();
ParentActor->RemoveSubActor(Actor);
// If the parent cluster is now empty (invalid) destroy it
if (!ParentActor->HasValidSubActors())
{
FHierarchicalLODUtilities::DestroyCluster(ParentActor);
}
}
// Add actor to new cluster
NewCluster->AddSubActor(Actor);
}
// Update sub actor LOD parents to populate
NewCluster->UpdateSubActorLODParents();
return NewCluster;
}
void FLODCluster::BuildActor(ULevel* InLevel, const int32 LODIdx, const bool bCreateMeshes)
{
FColor Colours[8] = { FColor::Cyan, FColor::Red, FColor::Green, FColor::Blue, FColor::Yellow, FColor::Magenta, FColor::White, FColor::Black };
// do big size
if (InLevel && InLevel->GetWorld())
{
// create asset using Actors
const FHierarchicalSimplification& LODSetup = InLevel->GetWorld()->GetWorldSettings()->HierarchicalLODSetup[LODIdx];
// Retrieve draw distance for current and next LOD level
const float DrawDistance = LODSetup.DrawDistance;
const int32 LODCount = InLevel->GetWorld()->GetWorldSettings()->HierarchicalLODSetup.Num();
const float NextDrawDistance = (LODIdx < (LODCount - 1)) ? InLevel->GetWorld()->GetWorldSettings()->HierarchicalLODSetup[LODIdx + 1].DrawDistance : 0.0f;
// Where generated assets will be stored
UPackage* AssetsOuter = InLevel->GetOutermost(); // this asset is going to save with map, this means, I'll have to delete with it
if (AssetsOuter)
{
TArray<UStaticMeshComponent*> AllComponents;
for (auto& Actor: Actors)
{
TArray<UStaticMeshComponent*> Components;
if (Actor->IsA<ALODActor>())
{
HierarchicalLODUtils::ExtractStaticMeshComponentsFromLODActor(Actor, Components);
}
else
{
Actor->GetComponents<UStaticMeshComponent>(Components);
}
// TODO: support instanced static meshes
Components.RemoveAll([](UStaticMeshComponent* Val){ return Val->IsA(UInstancedStaticMeshComponent::StaticClass()); });
AllComponents.Append(Components);
}
// it shouldn't even have come here if it didn't have any staticmesh
if (ensure(AllComponents.Num() > 0))
{
// In case we don't have outer generated assets should have same path as LOD level
const FString AssetsPath = AssetsOuter->GetName() + TEXT("/");
AActor* FirstActor = Actors[0];
TArray<UObject*> OutAssets;
FVector OutProxyLocation = FVector::ZeroVector;
UStaticMesh* MainMesh = nullptr;
if (bCreateMeshes)
{
// Generate proxy mesh and proxy material assets
IMeshUtilities& MeshUtilities = FModuleManager::Get().LoadModuleChecked<IMeshUtilities>("MeshUtilities");
// should give unique name, so use level + actor name
const FString PackageName = FString::Printf(TEXT("LOD_%s"), *FirstActor->GetName());
if (MeshUtilities.GetMeshMergingInterface() && LODSetup.bSimplifyMesh)
{
MeshUtilities.CreateProxyMesh(Actors, LODSetup.ProxySetting, AssetsOuter, PackageName, OutAssets, OutProxyLocation);
}
else
{
MeshUtilities.MergeStaticMeshComponents(AllComponents, FirstActor->GetWorld(), LODSetup.MergeSetting, AssetsOuter, PackageName, LODIdx, OutAssets, OutProxyLocation, LODSetup.DrawDistance, true);
}
// we make it private, so it can't be used by outside of map since it's useless, and then remove standalone
for (auto& AssetIter : OutAssets)
{
AssetIter->ClearFlags(RF_Public | RF_Standalone);
}
// set staticmesh
for (auto& Asset : OutAssets)
{
UStaticMesh* StaticMesh = Cast<UStaticMesh>(Asset);
if (StaticMesh)
{
MainMesh = StaticMesh;
}
}
}
if (MainMesh || !bCreateMeshes)
{
UWorld* LevelWorld = Cast<UWorld>(InLevel->GetOuter());
check (LevelWorld);
FTransform Transform;
Transform.SetLocation(OutProxyLocation);
// create LODActors using the current Actors
ALODActor* NewActor = nullptr;
NewActor = LevelWorld->SpawnActor<ALODActor>(ALODActor::StaticClass(), Transform);
NewActor->SubObjects = OutAssets;
NewActor->LODLevel = LODIdx+1;
NewActor->LODDrawDistance = DrawDistance;
NewActor->SetStaticMesh( MainMesh );
// now set as parent
for(auto& Actor : Actors)
{
NewActor->AddSubActor(Actor);
}
// Mark dirty according to whether or not this is a preview build
NewActor->SetIsDirty(!bCreateMeshes);
}
}
}
}
}