Additions to RuntimeMesh (RMCv4) functionality that provide somewhat more consistent simultaneous setting of multiple meshes' visibility and shadow-casting

RuntimeMesh.cpp

void URuntimeMesh::SetSectionVisibility(int32 LODIndex, int32 SectionId, bool bIsVisible)
{
	RMC_LOG_VERBOSE("SetSectionVisibility called: LOD:%d Section:%d IsVisible:%d", LODIndex, SectionId, bIsVisible);

	check(LODs.IsValidIndex(LODIndex));
	check(LODs[LODIndex].Sections.Contains(SectionId));

	FScopeLock Lock(&SyncRoot);

	FRuntimeMeshSectionProperties* Section = LODs[LODIndex].Sections.Find(SectionId);
	if (Section && Section->bIsVisible != bIsVisible)
	{
		Section->bIsVisible = bIsVisible;
		ESectionUpdateType& UpdateType = SectionsToUpdate.FindOrAdd(LODIndex).FindOrAdd(SectionId);
		UpdateType |= ESectionUpdateType::Properties;
		UpdateType = (UpdateType & ~ESectionUpdateType::ClearOrRemove);
		QueueForMeshUpdate();
	}
}

void URuntimeMesh::SetSectionCastsShadow(int32 LODIndex, int32 SectionId, bool bCastsShadow)
{
	RMC_LOG_VERBOSE("SetSectionCastsShadow called: LOD:%d Section:%d CastsShadow:%d", LODIndex, SectionId, bCastsShadow);

	check(LODs.IsValidIndex(LODIndex));
	check(LODs[LODIndex].Sections.Contains(SectionId));

	FScopeLock Lock(&SyncRoot);

	FRuntimeMeshSectionProperties* Section = LODs[LODIndex].Sections.Find(SectionId);
	if (Section && Section->bCastsShadow != bCastsShadow)
	{
		Section->bCastsShadow = bCastsShadow;
		ESectionUpdateType& UpdateType = SectionsToUpdate.FindOrAdd(LODIndex).FindOrAdd(SectionId);
		UpdateType |= ESectionUpdateType::Properties;
		UpdateType = (UpdateType & ~ESectionUpdateType::ClearOrRemove);
		QueueForMeshUpdate();
	}
}

//This is a Connor addition
void URuntimeMesh::ForceSetSectionVisibleAndCastsShadow(int32 LODIndex, int32 SectionId, bool bIsVisible, bool bCastsShadow)
{
	RMC_LOG_VERBOSE("ForceSetSectionVisibleAndCastsShadow called: LOD:%d Section:%d IsVisible:%d CastsShadow:%d", LODIndex, SectionId, bIsVisible, bCastsShadow);

	check(LODs.IsValidIndex(LODIndex));
	check(LODs[LODIndex].Sections.Contains(SectionId));

	FScopeLock Lock(&SyncRoot);

	FRuntimeMeshSectionProperties* Section = LODs[LODIndex].Sections.Find(SectionId);
	if (Section /*&& Section->bCastsShadow != bCastsShadow*/)
	{
		Section->bIsVisible = bIsVisible;
		Section->bCastsShadow = bCastsShadow;
		ESectionUpdateType& UpdateType = SectionsToUpdate.FindOrAdd(LODIndex).FindOrAdd(SectionId);
		UpdateType |= ESectionUpdateType::Properties;
		UpdateType = (UpdateType & ~ESectionUpdateType::ClearOrRemove);
		QueueForMeshUpdate();
	}
}

//This is a Connor addition
void URuntimeMesh::IMMEDIATE_ForceSetSectionVisibleAndCastsShadow(int32 LODIndex, int32 SectionId, bool bIsVisible, bool bCastsShadow)
{
	RMC_LOG_VERBOSE("IMMEDIATE_ForceSetSectionVisibleAndCastsShadow called: LOD:%d Section:%d IsVisible:%d CastsShadow:%d", LODIndex, SectionId, bIsVisible, bCastsShadow);

	check(LODs.IsValidIndex(LODIndex));
	check(LODs[LODIndex].Sections.Contains(SectionId));

	FScopeLock Lock(&SyncRoot);

	//FRuntimeMeshSectionProperties* Section = LODs[LODIndex].Sections.Find(SectionId);
	auto& Section = LODs[LODIndex].Sections[SectionId];
	//if (Section /*&& Section->bCastsShadow != bCastsShadow*/)
	if (true)
	{
		Section.bIsVisible = bIsVisible;
		Section.bCastsShadow = bCastsShadow;


		// NOTE: the below was copied from HandleUpdate.
		
		// TODO: this really shouldn't be necessary
		// but editor can sometimes force a delete
		FRuntimeMeshProxyPtr RenderProxyRef = RenderProxy;

		if (!RenderProxyRef.IsValid())
		{
			return;
		}

		FReadScopeLock ProviderLock(MeshProviderLock);
		if (MeshProviderPtr)
		{
			RenderProxyRef->CreateOrUpdateSection_GameThread(LODIndex, SectionId, Section, false);
		}
	}

}

//This is a Connor addition
void URuntimeMesh::MULTI_IMMEDIATE_ForceSetSectionVisibleAndCastsShadow(TArray<URuntimeMesh*> meshes, int32 LODIndex, TArray<int32> SectionIds, TArray<bool> bIsVisibles, TArray<bool> bCastsShadows)
{
	TRACE_CPUPROFILER_EVENT_SCOPE(MULTI_IMMEDIATE_ForceSetSectionVisibleAndCastsShadow);
	//RMC_LOG_VERBOSE("MULTI_IMMEDIATE_ForceSetSectionVisibleAndCastsShadow called: LOD:%d Section:%d IsVisible:%d CastsShadow:%d", LODIndex, SectionId, bIsVisible, bCastsShadow);

	//check(LODs.IsValidIndex(LODIndex));
	//check(LODs[LODIndex].Sections.Contains(SectionId));

	//FScopeLock Lock(&SyncRoot); //TODO

	TArray<TWeakPtr<FRuntimeMeshProxy, ESPMode::ThreadSafe>> ThisWeakRefs;

	for (int itr = 0; itr < meshes.Num(); itr++)
	{
		auto* mesh = meshes[itr];
		auto SectionId = SectionIds[itr];
		auto bIsVisible = bIsVisibles[itr];
		auto bCastsShadow = bCastsShadows[itr];

		auto& Section = mesh->LODs[LODIndex].Sections[SectionId];
		Section.bIsVisible = bIsVisible;
		Section.bCastsShadow = bCastsShadow;

		// TODO: this really shouldn't be necessary
		// but editor can sometimes force a delete
		FRuntimeMeshProxyPtr RenderProxyRef = mesh->RenderProxy;

		if (!RenderProxyRef.IsValid())
		{
			return;
		}

		FReadScopeLock ProviderLock(mesh->MeshProviderLock);
		if (mesh->MeshProviderPtr)
		{
			//RenderProxyRef->CreateOrUpdateSection_GameThread(LODIndex, SectionId, Section, false);
			RenderProxyRef->Deferred_CreateOrUpdateSection_GameThread(LODIndex, SectionId, Section, false);
			// This differs from CreateOrUpdateSection_GameThread by not running QueueForUpdate().
			// This means that we can do all the FlushPendingUpdates() in one ENQUEUE_RENDER_COMMAND.

			ThisWeakRefs.Add(RenderProxyRef);
		}
	}

	// QueueForUpdate() copy paste //
	// TODO: Is this really necessary. Enqueueing render commands fails sometimes when not called from game thread
	// We need to correctly support asynchronus submission 

	//if (!RenderProxyRef->IsQueuedForUpdate.AtomicSet(true)/* && GRenderingThread && !GIsRenderingThreadSuspended.Load(EMemoryOrder::Relaxed)*/)
	//{
	//	
	//}
	
	ENQUEUE_RENDER_COMMAND(FRuntimeMeshProxy_MultiUpdate)([ThisWeakRefs](FRHICommandListImmediate& RHICmdList)
		{
			for (auto ThisWeakRef : ThisWeakRefs)
			{
				auto Pinned = ThisWeakRef.Pin();
				if (Pinned)
				{
					Pinned->FlushPendingUpdates();
				}
			}
		});
}