void PxSerialization::createSerialObjectIds(PxCollection& collection, const PxSerialObjectId base)
{
	PxSerialObjectId localBase = base;
	PxU32 nbObjects = collection.getNbObjects();

	for (PxU32 i = 0; i < nbObjects; ++i)
	{
		while(collection.find(localBase))
		{
			localBase++;
		}

		PxBase& s = collection.getObject(i);		
		if(PX_SERIAL_OBJECT_ID_INVALID == collection.getId(s))
		{
			collection.addId(s, localBase);
			localBase++;
		}
	}
}
bool PxSerialization::isSerializable(PxCollection& collection, PxSerializationRegistry& sr, const PxCollection* externalReferences) 
{		
	PxCollection* subordinateCollection = PxCreateCollection();
	PX_ASSERT(subordinateCollection);

	for(PxU32 i = 0; i < collection.getNbObjects(); ++i)
	{
		PxBase& s = collection.getObject(i);
		const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
		PX_ASSERT(serializer);
		if(serializer->isSubordinate())
			subordinateCollection->add(s);

		if(externalReferences)
		{
			PxSerialObjectId id = collection.getId(s);
			if(id != PX_SERIAL_OBJECT_ID_INVALID)
			{
				PxBase* object = externalReferences->find(id);
				if(object && (object != &s))
				{					
					subordinateCollection->release();					
					Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
						"PxSerialization::isSerializable: Reference id %llu used both in current collection and in externalReferences. "
						"Please use unique identifiers.", id);	
					return false;
				}
			}
		}		
	}

	PxCollection* requiresCollection = PxCreateCollection();
	PX_ASSERT(requiresCollection);
		
	RequiresCallback requiresCallback0(*requiresCollection);

	for (PxU32 i = 0; i < collection.getNbObjects(); ++i)
	{
		PxBase& s = collection.getObject(i);
		const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
		PX_ASSERT(serializer);
		serializer->requires(s, requiresCallback0);

		Cm::Collection* cmRequiresCollection = static_cast<Cm::Collection*>(requiresCollection);

		for(PxU32 j = 0; j < cmRequiresCollection->getNbObjects(); ++j)
		{
			PxBase& s0 = cmRequiresCollection->getObject(j);

			if(subordinateCollection->contains(s0))
			{
				subordinateCollection->remove(s0);
				continue;
			}

			bool requiredIsInCollection = collection.contains(s0);
			if(!requiredIsInCollection)
			{
				if(externalReferences)
				{
					if(!externalReferences->contains(s0))
					{						
						Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
							"PxSerialization::isSerializable: Object of type %s references a missing object of type %s. "
							"The missing object needs to be added to either the current collection or the externalReferences collection.",
							s.getConcreteTypeName(), s0.getConcreteTypeName());						
					}
					else if(externalReferences->getId(s0) == PX_SERIAL_OBJECT_ID_INVALID)
					{						
						Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
							"PxSerialization::isSerializable: Object of type %s in externalReferences collection requires an id.", 
							s0.getConcreteTypeName());
					}
					else
						continue;
				}
				else
				{				
					Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
						"PxSerialization::isSerializable: Object of type %s references a missing serial object of type %s. "
						"Please completed the collection or specify an externalReferences collection containing the object.",
						s.getConcreteTypeName(), s0.getConcreteTypeName());					
				}
				subordinateCollection->release();
				requiresCollection->release();
				return false;	
			}		
		}
		cmRequiresCollection->mObjects.clear();
	}
	requiresCollection->release();
	
	PxU32 numOrphans = subordinateCollection->getNbObjects();
	
	for(PxU32 j = 0; j < numOrphans; ++j)
	{
		PxBase& subordinate = subordinateCollection->getObject(j);

		Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
			"PxSerialization::isSerializable: An object of type %s is subordinate but not required "
			"by other objects in the collection (orphan). Please remove the object from the collection or add its owner.", 
			subordinate.getConcreteTypeName());
	}
	
	subordinateCollection->release();

	if(numOrphans>0)
		return false;

	if(externalReferences)
	{
		PxCollection* oppositeRequiresCollection = PxCreateCollection();
		PX_ASSERT(oppositeRequiresCollection);

		RequiresCallback requiresCallback(*oppositeRequiresCollection);

		for (PxU32 i = 0; i < externalReferences->getNbObjects(); ++i)
		{
			PxBase& s = externalReferences->getObject(i);			
			const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
			PX_ASSERT(serializer);
			serializer->requires(s, requiresCallback);
		
			Cm::Collection* cmCollection = static_cast<Cm::Collection*>(oppositeRequiresCollection);

			for(PxU32 j = 0; j < cmCollection->getNbObjects(); ++j)
			{
				PxBase& s0 = cmCollection->getObject(j);

				if(collection.contains(s0))
				{
					oppositeRequiresCollection->release();
					Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
						"PxSerialization::isSerializable: Object of type %s in externalReferences references an object "
						"of type %s in collection (circular dependency).",
						s.getConcreteTypeName(), s0.getConcreteTypeName());
					return false;
				}
			}
			cmCollection->mObjects.clear();
		}
		oppositeRequiresCollection->release();
	}

	return true;
}
bool PxSerialization::isSerializable(PxCollection& collection, PxSerializationRegistry& sr, const PxCollection* externalReferences) 
{		
	bool bRet = true;	

	PxCollection* subordinateCollection = PxCreateCollection();
	PX_ASSERT(subordinateCollection);

	for(PxU32 i = 0; i < collection.getNbObjects(); ++i)
	{
		PxBase& s = collection.getObject(i);
		const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
		PX_ASSERT(serializer);
		if(serializer->isSubordinate())
			subordinateCollection->add(s);

		if(externalReferences)
		{
			PxSerialObjectId id = collection.getId(s);
			if(id != PX_SERIAL_OBJECT_ID_INVALID)
			{
				PxBase* object = externalReferences->find(id);
				if(object && (object != &s))
				{					
					subordinateCollection->release();
					Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
						"NpCollection::isSerializable: object shares reference name with other object in externalReferences (reference clash).");
					return false;
				}
			}
		}		
	}

	PxCollection* requiresCollection = PxCreateCollection();
	PX_ASSERT(requiresCollection);

	RequiresCallback requiresCallback0(*requiresCollection);

	for (PxU32 i = 0; i < collection.getNbObjects(); ++i)
	{
		PxBase& s = collection.getObject(i);
		const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
		PX_ASSERT(serializer);
		serializer->requires(s, requiresCallback0);
	}
	
	for(PxU32 j = 0; j < subordinateCollection->getNbObjects(); ++j)
	{
		PxBase& subordinate = subordinateCollection->getObject(j);
		bRet = requiresCollection->contains(subordinate);
		if(!bRet)
		{
			requiresCollection->release();
			subordinateCollection->release();
			Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
				"NpCollection::isSerializable: object is a subordinate and not required by other objects in the collection (orphan).");
			return false;		
		}
	}
	subordinateCollection->release();

	for(PxU32 j = 0; j < requiresCollection->getNbObjects(); ++j)
	{
		PxBase& s0 = requiresCollection->getObject(j);
		bRet = collection.contains(s0);
		if(!bRet && externalReferences)
		{
			bRet = externalReferences->contains(s0) &&  externalReferences->getId(s0) != PX_SERIAL_OBJECT_ID_INVALID;
		}
		if(!bRet)
		{
			requiresCollection->release();
			Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
				"NpCollection::isSerializable: cannot find a required serial object (collection is not complete).");
			return false;
		}
	}
	requiresCollection->release();

	if(externalReferences)
	{
		PxCollection* oppsiteRequiresCollection = PxCreateCollection();
		PX_ASSERT(oppsiteRequiresCollection);

		RequiresCallback requiresCallback(*oppsiteRequiresCollection);

		for (PxU32 i = 0; i < externalReferences->getNbObjects(); ++i)
		{
			PxBase& s = externalReferences->getObject(i);			
			const PxSerializer* serializer = sr.getSerializer(s.getConcreteType());
			PX_ASSERT(serializer);
			serializer->requires(s, requiresCallback);
		}

		for(PxU32 j = 0; j < oppsiteRequiresCollection->getNbObjects(); ++j)
		{
			PxBase& s0 = oppsiteRequiresCollection->getObject(j);

			if(collection.contains(s0))
			{
				oppsiteRequiresCollection->release();
				Ps::getFoundation().error(physx::PxErrorCode::eINVALID_PARAMETER, __FILE__, __LINE__, 
					"NpCollection::isSerializable: object in externalReferences requires an object in collection (circular dependency).");
				return false;
			}
		}
		oppsiteRequiresCollection->release();
	}

	return true;
}
	virtual bool SerializeActors(FName Format, const TArray<FBodyInstance*>& Bodies, const TArray<UBodySetup*>& BodySetups, const TArray<UPhysicalMaterial*>& PhysicalMaterials, TArray<uint8>& OutBuffer) const override
	{
#if WITH_PHYSX
		PxSerializationRegistry* PRegistry = PxSerialization::createSerializationRegistry(*GPhysXSDK);
		PxCollection* PCollection = PxCreateCollection();

		PxBase* PLastObject = nullptr;

		for(FBodyInstance* BodyInstance : Bodies)
		{
			if(BodyInstance->RigidActorSync)
			{
				PCollection->add(*BodyInstance->RigidActorSync, BodyInstance->RigidActorSyncId);
				PLastObject = BodyInstance->RigidActorSync;
			}

			if(BodyInstance->RigidActorAsync)
			{
				PCollection->add(*BodyInstance->RigidActorAsync,  BodyInstance->RigidActorAsyncId);
				PLastObject = BodyInstance->RigidActorAsync;
			}
		}

		PxSerialization::createSerialObjectIds(*PCollection, PxSerialObjectId(1));	//we get physx to assign an id for each actor

		//Note that rigid bodies may have assigned ids. It's important to let them go first because we rely on that id for deserialization.
		//One this is done we must find out the next available ID, and use that for naming the shared resources. We have to save this for deserialization
		uint64 BaseId = PLastObject ? (PCollection->getId(*PLastObject) + 1) : 1;

		PxCollection* PExceptFor = MakePhysXCollection(PhysicalMaterials, BodySetups, BaseId);
		
		for (FBodyInstance* BodyInstance : Bodies)	//and then we mark that id back into the bodyinstance so we can pair the two later
		{
			if (BodyInstance->RigidActorSync)
			{
				BodyInstance->RigidActorSyncId = PCollection->getId(*BodyInstance->RigidActorSync);
			}

			if (BodyInstance->RigidActorAsync)
			{
				BodyInstance->RigidActorAsyncId = PCollection->getId(*BodyInstance->RigidActorAsync);
			}
		}

		//We must store the BaseId for shared resources.
		FMemoryWriter Ar(OutBuffer);
		uint8 bIsLittleEndian = PLATFORM_LITTLE_ENDIAN; //TODO: We should pass the target platform into this function and write it. Then swap the endian on the writer so the reader doesn't have to do it at runtime
		Ar << bIsLittleEndian;
		Ar << BaseId;
		//Note that PhysX expects the binary data to be 128-byte aligned. Because of this we must pad
		int32 BytesToPad = PHYSX_SERIALIZATION_ALIGNMENT - (Ar.Tell() % PHYSX_SERIALIZATION_ALIGNMENT);
		OutBuffer.AddZeroed(BytesToPad);

		FPhysXOutputStream Buffer(&OutBuffer);
		PxSerialization::complete(*PCollection, *PRegistry, PExceptFor);
		PxSerialization::serializeCollectionToBinary(Buffer, *PCollection, *PRegistry, PExceptFor);

#if PHYSX_MEMORY_VALIDATION
		GPhysXAllocator->ValidateHeaders();
#endif
		PCollection->release();
		PExceptFor->release();
		PRegistry->release();

#if PHYSX_MEMORY_VALIDATION
		GPhysXAllocator->ValidateHeaders();
#endif
		return true;
#endif
		return false;
	}