diff --git a/LibCmo/CK2/CKContext.cpp b/LibCmo/CK2/CKContext.cpp
index 4088707..71120cc 100644
--- a/LibCmo/CK2/CKContext.cpp
+++ b/LibCmo/CK2/CKContext.cpp
@@ -14,7 +14,7 @@ namespace LibCmo::CK2 {
 #pragma region Ctor Dtor
 
 	CKContext::CKContext() :
-		m_ObjectsList(), m_ReturnedObjectIds(),
+		m_ObjectsList(), m_ReturnedObjectOffsets(),
 		m_GroupGlobalIndex(), m_SceneGlobalIndex(),
 		m_CompressionLevel(5), m_FileWriteMode(CK_FILE_WRITEMODE::CKFILE_UNCOMPRESSED),
 		m_NameEncoding(), m_TempFolder(),
@@ -29,147 +29,28 @@ namespace LibCmo::CK2 {
 	}
 
 	CKContext::~CKContext() {
-		DestroyAllCKObjects();
+		ClearAll();
 	}
 
 #pragma endregion
 
 #pragma region Objects Management
 
-	ObjImpls::CKObject* CKContext::CreateObject(CK_CLASSID cls, CKSTRING name,
-		CK_OBJECTCREATION_OPTIONS options, CK_CREATIONMODE* res) {
-		// todo: Process paramter options and res
+	void CKContext::ClearAll() {
 
-		// get description first
-		const CKClassDesc* desc = CKGetClassDesc(cls);
-		if (desc == nullptr) return nullptr;
-
-		// allocate a CK_ID first
-		CK_ID decided_id;
-		if (this->m_ReturnedObjectIds.empty()) {
-			// create new CK_ID.
-			decided_id = static_cast<CK_ID>(m_ObjectsList.size());
-			m_ObjectsList.resize(decided_id + 1);
-		} else {
-			// use returned CK_ID.
-			decided_id = m_ReturnedObjectIds.back();
-			m_ReturnedObjectIds.pop_back();
-		}
-
-		// create one
-		ObjImpls::CKObject* obj = desc->CreationFct(this, decided_id + c_ObjectIdOffset, name);
-
-		// put into slot
-		m_ObjectsList[decided_id] = obj;
-		
-		// set out variable
-		return obj;
-	}
-
-	ObjImpls::CKObject* CKContext::GetObject(CK_ID id) {
-		id -= c_ObjectIdOffset;
-		if (id >= m_ObjectsList.size()) return nullptr;
-		return m_ObjectsList[id];
-	}
-
-	/**
-	 * @brief The real CKObject destroy worker shared by CKContext::DestroyObject and CKContext::~CKContext
-	 * @param[in] ctx The CKContext
-	 * @param[in] obj The CKObject need to be free.
-	*/
-	static void InternalDestroy(CKContext* ctx, ObjImpls::CKObject* obj) {
-		// find desc by classid
-		// if really we can not find it, we only can delete it directly.
-		const CKClassDesc* desc = CKGetClassDesc(obj->GetClassID());
-		if (desc == nullptr) {
-			delete obj;
-			return;
-		}
-
-		// free it and return its value
-		desc->ReleaseFct(ctx, obj);
-	}
-	void CKContext::DestroyObject(CK_ID id) {
-		id -= c_ObjectIdOffset;
-		if (id >= m_ObjectsList.size()) return;
-
-		// get object and free it
-		ObjImpls::CKObject* obj = m_ObjectsList[id];
-		if (obj == nullptr) return;
-		InternalDestroy(this, obj);
-		
-		// return its allocated id.
-		m_ObjectsList[id] = nullptr;
-		m_ReturnedObjectIds.emplace_back(id);
-
-	}
-
-	CKDWORD CKContext::AllocateGroupGlobalIndex() {
-		// try find first non-true position
-		CKDWORD index;
-		if (!XContainer::XBitArrayPatch::GetSetBitPosition(m_GroupGlobalIndex, 0, index)) {
-			// failed. distribute new one
-			index = static_cast<CKDWORD>(m_GroupGlobalIndex.size());
-			m_GroupGlobalIndex.resize(m_GroupGlobalIndex.size() + 1);
-		}
-		
-		// set to occupy
-		m_GroupGlobalIndex[index] = true;
-		return index;
-	}
-
-	CKDWORD CKContext::AllocateSceneGlobalIndex() {
-		// same as group
-		CKDWORD index;
-		if (!XContainer::XBitArrayPatch::GetSetBitPosition(m_SceneGlobalIndex, 0, index)) {
-			index = static_cast<CKDWORD>(m_SceneGlobalIndex.size());
-			m_SceneGlobalIndex.resize(m_SceneGlobalIndex.size() + 1);
-		}
-		
-		m_SceneGlobalIndex[index] = true;
-		return index;
-	}
-
-	void CKContext::FreeGroupGlobalIndex(CKDWORD id) {
-		// check position
-		if (id >= m_GroupGlobalIndex.size()) return;
-		// set value
-		m_GroupGlobalIndex[id] = false;
-	}
-
-	void CKContext::FreeSceneGlobalIndex(CKDWORD id) {
-		// same as group
-		if (id >= m_SceneGlobalIndex.size()) return;
-		m_SceneGlobalIndex[id] = false;
-	}
-	
-	void CKContext::DestroyAllCKObjects() {
-		// free all created objects
-		for (auto& ptr : m_ObjectsList) {
-			if (ptr != nullptr) {
-				InternalDestroy(this, ptr);
-			}
-		}
-		// restore returned object list
-		m_ReturnedObjectIds.clear();
-		// empty object list
-		m_ObjectsList.clear();
-
-		// clear group and scene global index at the same time
-		m_SceneGlobalIndex.clear();
-		m_GroupGlobalIndex.clear();
 	}
 
 #pragma endregion
 
 #pragma region Common Manager Functions
 	
-	CKINT CKContext::GetManagerCount() {
-		return 0;
+	CKDWORD CKContext::GetManagerCount() {
+		return m_ManagerList.size();
 	}
 
-	MgrImpls::CKBaseManager* CKContext::GetManager(CKINT index) {
-		return nullptr;
+	MgrImpls::CKBaseManager* CKContext::GetManager(CKDWORD index) {
+		if (index >= m_ManagerList.size()) return nullptr;
+		return m_ManagerList[index];
 	}
 
 #pragma endregion
diff --git a/LibCmo/CK2/CKContext.hpp b/LibCmo/CK2/CKContext.hpp
index f754d88..6111ab0 100644
--- a/LibCmo/CK2/CKContext.hpp
+++ b/LibCmo/CK2/CKContext.hpp
@@ -21,61 +21,44 @@ namespace LibCmo::CK2 {
 	class CKContext {
 	public:
 		CKContext();
-		CKContext(const CKContext&) = delete;
-		CKContext& operator=(const CKContext&) = delete;
 		~CKContext();
-
-		// ========== Objects Management ==========
+		LIBCMO_DISABLE_COPY_MOVE(CKContext);
 
 		/**
-		 * @brief Creates a CKObject or derived class instance.
-		 * @param[in] cls Class Identifier (CK_CLASSID) of the object to create.
-		 * @param[in] name The name of this object.
-		 * @param[in] options Tell CKContext how to create this object when conflict happended.
-		 * @param[out] res The value indicate the real method how this object created.
-		 * @return A pointer to the newly created object.
-		 * @remark CKObjects must be destroy with the DestroyObject method.
-		 * @see CKObject, DestroyObject
+		 * @brief Simply clear all CKContext to restore its status.
 		*/
-		ObjImpls::CKObject* CreateObject(CK_CLASSID cls, CKSTRING name,
-			CK_OBJECTCREATION_OPTIONS options = CK_OBJECTCREATION_OPTIONS::CK_OBJECTCREATION_NONAMECHECK, 
-			CK_CREATIONMODE* res = nullptr);
-		ObjImpls::CKObject* GetObject(CK_ID id);
-		void DestroyObject(CK_ID id);
+		void ClearAll();
 
-		CKDWORD AllocateGroupGlobalIndex();
-		CKDWORD AllocateSceneGlobalIndex();
-		void FreeGroupGlobalIndex(CKDWORD id);
-		void FreeSceneGlobalIndex(CKDWORD id);
+		// ========== Common Managers ==========
 
-		void DestroyAllCKObjects();
+		MgrImpls::CKObjectManager* GetObjectManager();
+		MgrImpls::CKPathManager* GetPathManager();
 
-		// ========== Object Access ==========
+		CKDWORD GetManagerCount();
+		MgrImpls::CKBaseManager* GetManager(CKDWORD index);
 
-		//CKManagerImplements::CKBaseManager* CreateCKManager(CKGUID guid);
-		//CKManagerImplements::CKBaseManager* GetCKManager(CK_ID guid);
-		//void DestroyCKManager(CKManagerImplements::CKBaseManager* mgr);
-
-		//CKObject* GetObjectByName(CKSTRING name, CKObject* previous = NULL);
-		//CKObject* GetObjectByNameAndClass(CKSTRING name, CK_CLASSID cid, CKObject* previous = NULL);
-		//CKObject* GetObjectByNameAndParentClass(CKSTRING name, CK_CLASSID pcid, CKObject* previous);
-		//const XContainer::XObjectPointerArray GetObjectListByType(CK_CLASSID cid, CKBOOL derived);
-		//CKINT GetObjectsCountByClassID(CK_CLASSID cid);
-		//CK_ID* GetObjectsListByClassID(CK_CLASSID cid);
-
-		// ========== Common Managers Functions ==========
-
-		CKINT GetManagerCount();
-		MgrImpls::CKBaseManager* GetManager(CKINT index);
+		void ExecuteManagersOnPreClearAll();
+		void ExecuteManagersOnPostClearAll();
+		void ExecuteManagersSequenceToBeDeleted();
+		void ExecuteManagersSequenceDeleted();
 
 		// ========== File Save/Load Options ==========
-		
+
 		void SetCompressionLevel(CKINT level);
 		CKINT GetCompressionLevel();
 
 		void SetFileWriteMode(CK_FILE_WRITEMODE mode);
 		CK_FILE_WRITEMODE GetFileWriteMode();
 
+		CK_TEXTURE_SAVEOPTIONS GetGlobalImagesSaveOptions();
+		void SetGlobalImagesSaveOptions(CK_TEXTURE_SAVEOPTIONS Options);
+
+		CKBitmapProperties* GetGlobalImagesSaveFormat();
+		void SetGlobalImagesSaveFormat(CKBitmapProperties* Format);
+
+		CK_SOUND_SAVEOPTIONS GetGlobalSoundsSaveOptions();
+		void SetGlobalSoundsSaveOptions(CK_SOUND_SAVEOPTIONS Options);
+
 		// ========== Encoding utilities ==========
 
 		void GetUtf8String(const std::string& native_name, std::string& u8_name);
@@ -95,24 +78,16 @@ namespace LibCmo::CK2 {
 		void SetOutputCallback(OutputCallback cb);
 
 	protected:
-		// ========== Objects Management ==========
-
-		/**
-		 * The global offset of created CK_ID.
-		 * The value close to zero may cause some issue.
-		 * So we add a static offset to every created CK_ID.
-		*/
-		const CK_ID c_ObjectIdOffset = 61u;
-
-		XContainer::XArray<ObjImpls::CKObject*> m_ObjectsList;
-		std::deque<CK_ID> m_ReturnedObjectIds;
-
-		XContainer::XBitArray m_GroupGlobalIndex;
-		XContainer::XBitArray m_SceneGlobalIndex;
+		// ========== Common Managers ==========
+		void ExecuteManagersGeneral(std::function<void(MgrImpls::CKBaseManager*)> fct);
+		XContainer::XArray<MgrImpls::CKBaseManager*> m_ManagerList;
 
 		// ========== File Save/Load Options ==========
 		CKINT m_CompressionLevel;
 		CK_FILE_WRITEMODE m_FileWriteMode;
+		CK_TEXTURE_SAVEOPTIONS m_GlobalImagesSaveOptions;
+		CK_SOUND_SAVEOPTIONS m_GlobalSoundsSaveOptions;
+		CKBitmapProperties* m_GlobalImagesSaveFormat;
 
 		// ========== Encoding utilities ==========
 
diff --git a/LibCmo/CK2/CKFileReader.cpp b/LibCmo/CK2/CKFileReader.cpp
index 71ac9b0..c1c6aef 100644
--- a/LibCmo/CK2/CKFileReader.cpp
+++ b/LibCmo/CK2/CKFileReader.cpp
@@ -348,7 +348,7 @@ namespace LibCmo::CK2 {
 			if (obj.Data == nullptr) continue;
 
 			// create object and assign created obj ckid
-			obj.ObjPtr = m_Ctx->CreateObject(obj.ObjectCid, obj.Name.c_str());
+			obj.ObjPtr = m_Ctx->CreateObject(obj.ObjectCid, obj.Name.toCKSTRING());
 			if (obj.ObjPtr == nullptr) {
 				obj.CreatedObjectId = 0u;
 			} else {
diff --git a/LibCmo/CK2/CKFileWriter.cpp b/LibCmo/CK2/CKFileWriter.cpp
index 0057bb5..2c751ba 100644
--- a/LibCmo/CK2/CKFileWriter.cpp
+++ b/LibCmo/CK2/CKFileWriter.cpp
@@ -89,9 +89,9 @@ namespace LibCmo::CK2 {
 		for (auto& obj : m_FileObjects) {
 			// += 4DWORD(ObjId, ObjCid, FileIndex, NameLen)
 			sumHdrObjSize += 4 * CKSizeof(CKDWORD);
-			if (obj.Name.c_str() != nullptr) {
+			if (obj.Name.toCKSTRING() != nullptr) {
 				// += Name size
-				m_Ctx->GetNativeString(obj.Name.string(), name_conv);
+				m_Ctx->GetNativeString(obj.Name.toString(), name_conv);
 				sumHdrObjSize += static_cast<CKDWORD>(name_conv.size());
 			}
 
@@ -176,8 +176,8 @@ namespace LibCmo::CK2 {
 			hdrparser->Write(&obj.ObjectCid, sizeof(CK_CLASSID));
 			hdrparser->Write(&obj.FileIndex, sizeof(CKDWORD));
 
-			if (obj.Name.c_str() != nullptr) {
-				m_Ctx->GetNativeString(obj.Name.string(), name_conv);
+			if (obj.Name.toCKSTRING() != nullptr) {
+				m_Ctx->GetNativeString(obj.Name.toString(), name_conv);
 				CKDWORD namelen = static_cast<CKDWORD>(name_conv.size());
 				hdrparser->Write(&namelen, sizeof(CKDWORD));
 				hdrparser->Write(name_conv.data(), namelen);
diff --git a/LibCmo/CK2/CKGlobals.cpp b/LibCmo/CK2/CKGlobals.cpp
index 82755bc..23eb8e0 100644
--- a/LibCmo/CK2/CKGlobals.cpp
+++ b/LibCmo/CK2/CKGlobals.cpp
@@ -64,6 +64,22 @@ namespace LibCmo::CK2 {
 
 #pragma endregion
 
+#pragma region String Utilities 
+
+	bool CKStrEqual(CKSTRING str1, CKSTRING str2) {
+		if (str1 == nullptr) {
+			if (str2 == nullptr) return true;
+			else return false;
+		} else {
+			if (str2 == nullptr) return false;
+			else {
+				return std::strcmp(str1, str2) == 0;
+			}
+		}
+	}
+
+#pragma endregion
+
 #pragma region CKClass Registration
 
 	static XContainer::XArray<CKClassDesc> g_CKClassInfo;
diff --git a/LibCmo/CK2/CKGlobals.hpp b/LibCmo/CK2/CKGlobals.hpp
index cac3f72..a03a22d 100644
--- a/LibCmo/CK2/CKGlobals.hpp
+++ b/LibCmo/CK2/CKGlobals.hpp
@@ -45,6 +45,10 @@ namespace LibCmo::CK2 {
 	*/
 	CKDWORD CKComputeDataCRC(const void* data, CKDWORD size, CKDWORD PreviousCRC = 0);
 
+	// ========== String Utilities ==========
+
+	bool CKStrEqual(CKSTRING str1, CKSTRING str2);
+
 	// ========== Numberic Utilities ==========
 
 	/*
diff --git a/LibCmo/CK2/CKTypes.hpp b/LibCmo/CK2/CKTypes.hpp
index 9c0af23..8cb99cc 100644
--- a/LibCmo/CK2/CKTypes.hpp
+++ b/LibCmo/CK2/CKTypes.hpp
@@ -272,6 +272,7 @@ namespace LibCmo::CK2 {
 	//--- Managers
 	namespace MgrImpls {
 		class CKBaseManager;
+		class CKObjectManager;
 		class CKSoundManager;
 		class CKTimeManager;
 		class CKRenderManager;
diff --git a/LibCmo/CK2/MgrImpls/CKBaseManager.hpp b/LibCmo/CK2/MgrImpls/CKBaseManager.hpp
index 46fe30a..f0f5cfe 100644
--- a/LibCmo/CK2/MgrImpls/CKBaseManager.hpp
+++ b/LibCmo/CK2/MgrImpls/CKBaseManager.hpp
@@ -2,6 +2,28 @@
 
 #include "../../VTAll.hpp"
 
+/**
+CKBaseManager virtual functions implementations help
+All virtual functions is not supported except we implemented.
+
+Read/Write functions:
+- SaveData()
+- LoadData()
+
+Clear functions:
+- PreClearAll()
+- PostClearAll()
+
+Delete functions:
+- SequenceToBeDeleted()
+- SequenceDeleted()
+
+Moved functions
+- OnCKInit(): Implement in ctor
+- OnCKEnd(): Implement in dtor
+
+*/
+
 namespace LibCmo::CK2::MgrImpls {
 
 	/**
@@ -16,8 +38,7 @@ namespace LibCmo::CK2::MgrImpls {
 		CKBaseManager(CKContext* ctx, CKGUID guid, CKSTRING name) :
 			m_ManagerGuid(guid),
 			m_ManagerName(name),
-			m_Context(ctx)
-		{}
+			m_Context(ctx) {}
 		virtual ~CKBaseManager() {}
 		LIBCMO_DISABLE_COPY_MOVE(CKBaseManager);
 
@@ -37,8 +58,8 @@ namespace LibCmo::CK2::MgrImpls {
 			```
 		@see CKContext::RegisterNewManager, GetName
 		*/
-		CKGUID GetGuid() { 
-			return m_ManagerGuid; 
+		CKGUID GetGuid() {
+			return m_ManagerGuid;
 		}
 		/**
 		@brief Acces to Manager name
@@ -55,14 +76,14 @@ namespace LibCmo::CK2::MgrImpls {
 			}
 			```
 		*/
-		CKSTRING GetName() { 
-			return m_ManagerName.c_str();
+		CKSTRING GetName() {
+			return m_ManagerName.toCKSTRING();
 		}
 
 		/**
 		@brief Called to save manager data.
 		@param SavedFile A pointer to the CKFile being saved.
-		@return This function should return a valid CKStateChunk that contain data to save or NULL if there is nothing to save.
+		@return This function should return true or false if there is nothing to save.
 		@remark
 			+ During a save operation, each manager is given the opportunity to save its data in the file.
 			+ The file being saved is given for information only and must not be modified. It can be used to decide whether it is worth saving
@@ -70,21 +91,68 @@ namespace LibCmo::CK2::MgrImpls {
 		@see CKStateChunk, LoadData
 		*/
 		virtual bool SaveData(CKStateChunk* chunk, CKFileVisitor* SavedFile) {
-			return true;
+			return false;	// default value is false to indicate this manager do not need save any data.
 		}
 		/**
 		@brief Called to load manager data.
 		@param chunk A pointer to a CKStateChunk that was saved in the file.
 		@param LoadedFile A pointer to the CKFile being loaded.
-		@return CK_OK if successful or an error code otherwise.
+		@return CKERR_OK if successful or an error code otherwise.
 		@remark
 			+ During a load operation, each manager is automatically called if there was a chunk saved in the file with SaveData.
 		@see CKStateChunk, SaveData
 		*/
 		virtual CKERROR LoadData(CKStateChunk* chunk, CKFileVisitor* LoadedFile) {
-			return CKERROR::CKERR_OK; 
+			return CKERROR::CKERR_OK;
 		}
 
+		/**
+		@brief Called at the beginning of a CKContext::ClearAll operation.
+		@return CK_OK if successful or an error code otherwise.
+		@remark
+			+ You can override this function to add specific processing at the beginning of a CKContext::ClearAll operation.
+			+ You must override GetValidFunctionsMask and return a value including
+			CKMANAGER_FUNC_PreClearAll for this function to get called.
+		@see Main Virtools Events, PostClearAll, CKContext::ClearAll
+		*/
+		virtual CKERROR PreClearAll() { return CKERROR::CKERR_OK; }
+		/**
+		@brief Called at the end of a CKContext::ClearAll operation.
+		@return CKERR_OK if successful or an error code otherwise.
+		@remark
+			+ You can override this function to add specific processing at the end of a CKContext::ClearAll operation.
+			+ You must override GetValidFunctionsMask and return a value including
+			CKMANAGER_FUNC_PostClearAll for this function to get called.
+		@see Main Virtools Events, PreClearAll, CKContext::ClearAll
+		*/
+		virtual CKERROR PostClearAll() { return CKERROR::CKERR_OK; }
+
+		/**
+		@brief Called just before objects are deleted.
+		@return CK_OK if successful or an error code otherwise.
+		@param objids[in] A pointer to a list of CK_ID of the objects being deleted.
+		@param count[in] number of objects in objids list.
+		@remark
+			+ You can override this function if you need to add specific processing before objects are deleted.
+			+ You must override GetValidFunctionsMask and return a value including
+			CKMANAGER_FUNC_OnSequenceToBeDeleted for this function to get called.
+		@see Main Virtools Events, CKContext::DestroyObjects, SequenceDeleted
+		*/
+		virtual CKERROR SequenceToBeDeleted(const CK_ID* objids, CKDWORD count) { return CKERROR::CKERR_OK; }
+		/**
+		@brief Called after objects have been deleted.
+		@return CK_OK if successful or an error code otherwise.
+		@param objids[in] A pointer to a list of CK_ID of the objects being deleted.
+		@param count[in] number of objects in objids list.
+		@remark
+			+ You can override this function if you need to add specific processing after objects have been deleted.
+			+ You must override GetValidFunctionsMask and return a value including
+			CKMANAGER_FUNC_OnSequenceDeleted for this function to get called.
+		@see Main Virtools Events, CKContext::DestroyObjects, SequenceToBeDeleted
+		*/
+		virtual CKERROR SequenceDeleted(const CK_ID* objids, CKDWORD count) { return CKERROR::CKERR_OK; }
+
+
 	protected:
 		CKGUID m_ManagerGuid; ///> Manager GUID
 		TypeHelper::MKString m_ManagerName; ///> Manager Name
diff --git a/LibCmo/CK2/MgrImpls/CKObjectManager.cpp b/LibCmo/CK2/MgrImpls/CKObjectManager.cpp
new file mode 100644
index 0000000..2336420
--- /dev/null
+++ b/LibCmo/CK2/MgrImpls/CKObjectManager.cpp
@@ -0,0 +1,196 @@
+#include "CKObjectManager.hpp"
+#include "../ObjImpls/CKObject.hpp"
+
+namespace LibCmo::CK2::MgrImpls {
+
+	CKObjectManager::CKObjectManager(CKContext* ctx) :
+		CKBaseManager(ctx, OBJECT_MANAGER_GUID, "Object Manager"),
+		m_ObjectsList(), m_ReturnedObjectOffsets(), m_ObjectCount(0),
+		m_GroupGlobalIndex(), m_SceneGlobalIndex(),
+		m_ObjectsListByClass(CKGetClassCount()) {}
+
+	CKObjectManager::~CKObjectManager() {
+		DestroyAllObjects();
+	}
+
+	ObjImpls::CKObject* CKObjectManager::CreateObject(CK_CLASSID cls, CKSTRING name,
+		CK_OBJECTCREATION_OPTIONS options, CK_CREATIONMODE* res) {
+		// todo: Process paramter options and res
+
+		// get description first
+		const CKClassDesc* desc = CKGetClassDesc(cls);
+		if (desc == nullptr) return nullptr;
+
+		// allocate a CK_ID first
+		CKDWORD decided_off;
+		if (this->m_ReturnedObjectOffsets.empty()) {
+			// create new CK_ID.
+			decided_off = static_cast<CKDWORD>(m_ObjectsList.size());
+			m_ObjectsList.resize(decided_off + 1);
+		} else {
+			// use returned CK_ID.
+			decided_off = m_ReturnedObjectOffsets.back();
+			m_ReturnedObjectOffsets.pop_back();
+		}
+
+		// create one
+		ObjImpls::CKObject* obj = desc->CreationFct(m_Context, Offset2Id(decided_off), name);
+
+		// put into slot and inc count
+		m_ObjectsList[decided_off] = obj;
+		++m_ObjectCount;
+
+		// set out variable
+		return obj;
+	}
+
+	ObjImpls::CKObject* CKObjectManager::GetObject(CK_ID id) {
+		CKDWORD off = Id2Offset(id);
+		if (off >= m_ObjectsList.size()) return nullptr;
+		return m_ObjectsList[off];
+	}
+
+	CKDWORD CKObjectManager::GetObjectCount() {
+		return m_ObjectCount;
+	}
+
+	void CKObjectManager::InternalDestroy(ObjImpls::CKObject* obj) {
+		// find desc by classid
+		// if really we can not find it, we only can delete it directly.
+		const CKClassDesc* desc = CKGetClassDesc(obj->GetClassID());
+		if (desc == nullptr) {
+			delete obj;
+			return;
+		}
+
+		// free it
+		desc->ReleaseFct(m_Context, obj);
+	}
+
+	void CKObjectManager::DestroyObject(CK_ID id) {
+		CKDWORD off = Id2Offset(id);
+		if (off >= m_ObjectsList.size()) return;
+
+		// get object and free it
+		ObjImpls::CKObject* obj = m_ObjectsList[off];
+		if (obj == nullptr) return;
+		InternalDestroy(obj);
+
+		// return its allocated id.
+		// and dec count
+		m_ObjectsList[off] = nullptr;
+		m_ReturnedObjectOffsets.emplace_back(off);
+		--m_ObjectCount;
+
+	}
+
+	void CKObjectManager::DestroyAllObjects() {
+		// free all created objects
+		for (auto& ptr : m_ObjectsList) {
+			if (ptr != nullptr) {
+				InternalDestroy(ptr);
+			}
+		}
+		// restore returned object list
+		m_ReturnedObjectOffsets.clear();
+		// empty object list
+		m_ObjectsList.clear();
+		// reset count
+		m_ObjectCount = 0;
+
+		// clear obj by class list
+		for (auto& ls : m_ObjectsListByClass) {
+			ls.clear();
+		}
+
+		// clear group and scene global index at the same time
+		m_SceneGlobalIndex.clear();
+		m_GroupGlobalIndex.clear();
+	}
+
+	XContainer::XObjectPointerArray CKObjectManager::GetObjectByNameAndClass(CKSTRING name, CK_CLASSID cid, bool derived) {
+		XContainer::XObjectPointerArray result;
+		
+		for (size_t i = 0; i < m_ObjectsListByClass.size(); ++i) {
+			// check class id first
+			if (derived) {
+				if (!CKIsChildClassOf(static_cast<CK_CLASSID>(i), cid)) continue;
+			} else {
+				if (static_cast<CK_CLASSID>(i) != cid) continue;
+			}
+			
+			// iterate all sub object and check name
+			for (const auto& objoff : m_ObjectsListByClass[i]) {
+				ObjImpls::CKObject* obj = m_ObjectsList[objoff];
+
+				if (name == nullptr) {
+					// directly add
+					result.emplace_back(obj);
+				} else {
+					// check name
+					if (CKStrEqual(name, obj->GetName())) {
+						result.emplace_back(obj);
+					}
+				}
+			}
+		}
+	}
+
+	CKDWORD CKObjectManager::AllocateGroupGlobalIndex(ObjImpls::CKObject* group) {
+		// try find first nullptr position
+		CKDWORD index = 0;
+		for (const auto& ptr : m_GroupGlobalIndex) {
+			if (ptr == nullptr) break;
+			++index;
+		}
+		// resize array for new position
+		if (index == m_GroupGlobalIndex.size()) {
+			m_GroupGlobalIndex.resize(m_GroupGlobalIndex.size() + 1);
+		}
+
+		// set to occupy
+		m_GroupGlobalIndex[index] = group;
+		return index;
+	}
+
+	CKDWORD CKObjectManager::AllocateSceneGlobalIndex(ObjImpls::CKObject* scene) {
+		// same as group
+		CKDWORD index = 0;
+		for (const auto& ptr : m_SceneGlobalIndex) {
+			if (ptr == nullptr) break;
+			++index;
+		}
+		// resize array for new position
+		if (index == m_SceneGlobalIndex.size()) {
+			m_SceneGlobalIndex.resize(m_SceneGlobalIndex.size() + 1);
+		}
+
+		// set to occupy
+		m_SceneGlobalIndex[index] = scene;
+		return index;
+	}
+
+	ObjImpls::CKObject* CKObjectManager::GetGroupByGlobalIndex(CKDWORD index) {
+		if (index >= m_GroupGlobalIndex.size()) return nullptr;
+		else return m_GroupGlobalIndex[index];
+	}
+
+	ObjImpls::CKObject* CKObjectManager::GetSceneByGlobalIndex(CKDWORD index) {
+		if (index >= m_SceneGlobalIndex.size()) return nullptr;
+		else return m_SceneGlobalIndex[index];
+	}
+
+	void CKObjectManager::FreeGroupGlobalIndex(CKDWORD id) {
+		// check position
+		if (id >= m_GroupGlobalIndex.size()) return;
+		// set value
+		m_GroupGlobalIndex[id] = nullptr;
+	}
+
+	void CKObjectManager::FreeSceneGlobalIndex(CKDWORD id) {
+		// same as group
+		if (id >= m_SceneGlobalIndex.size()) return;
+		m_SceneGlobalIndex[id] = nullptr;
+	}
+
+}
diff --git a/LibCmo/CK2/MgrImpls/CKObjectManager.hpp b/LibCmo/CK2/MgrImpls/CKObjectManager.hpp
new file mode 100644
index 0000000..ce6d88c
--- /dev/null
+++ b/LibCmo/CK2/MgrImpls/CKObjectManager.hpp
@@ -0,0 +1,81 @@
+#pragma once
+
+#include "../../VTAll.hpp"
+#include "CKBaseManager.hpp"
+#include <deque>
+
+namespace LibCmo::CK2::MgrImpls {
+
+	class CKObjectManager : public CKBaseManager {
+	public:
+		CKObjectManager(CKContext* ctx);
+		virtual ~CKObjectManager();
+		LIBCMO_DISABLE_COPY_MOVE(CKObjectManager);
+
+		// ========== Objects Management ==========
+
+		/**
+		 * @brief Creates a CKObject or derived class instance.
+		 * @param[in] cls Class Identifier (CK_CLASSID) of the object to create.
+		 * @param[in] name The name of this object.
+		 * @param[in] options Tell CKContext how to create this object when conflict happended.
+		 * @param[out] res The value indicate the real method how this object created.
+		 * @return A pointer to the newly created object.
+		 * @remark CKObjects must be destroy with the DestroyObject method.
+		 * @see CKObject, DestroyObject
+		*/
+		ObjImpls::CKObject* CreateObject(CK_CLASSID cls, CKSTRING name,
+			CK_OBJECTCREATION_OPTIONS options = CK_OBJECTCREATION_OPTIONS::CK_OBJECTCREATION_NONAMECHECK,
+			CK_CREATIONMODE* res = nullptr);
+		// todo: implement CopyObject by CKClassDesc
+		//ObjImpls::CKObject* CopyObject(ObjImpls::CKObject *src,
+		//	CKDependencies* Dependencies = nullptr,
+		//	CKSTRING AppendName = nullptr,
+		//	CK_OBJECTCREATION_OPTIONS Options = CK_OBJECTCREATION_OPTIONS::CK_OBJECTCREATION_NONAMECHECK);
+
+		ObjImpls::CKObject* GetObject(CK_ID id);
+		CKDWORD GetObjectCount();
+		void DestroyObject(CK_ID id);
+		void DestroyAllObjects();
+
+		// ========== Objects Access ==========
+
+		XContainer::XObjectPointerArray GetObjectByNameAndClass(
+			CKSTRING name, CK_CLASSID cid, bool derived);
+
+		// ========== Special Functions ==========
+
+		CKDWORD AllocateGroupGlobalIndex(ObjImpls::CKObject* group);
+		CKDWORD AllocateSceneGlobalIndex(ObjImpls::CKObject* scene);
+		ObjImpls::CKObject* GetGroupByGlobalIndex(CKDWORD index);
+		ObjImpls::CKObject* GetSceneByGlobalIndex(CKDWORD index);
+		void FreeGroupGlobalIndex(CKDWORD id);
+		void FreeSceneGlobalIndex(CKDWORD id);
+
+	protected:
+		/**
+		 * The global offset of created CK_ID.
+		 * The value close to zero may cause some issue.
+		 * So we add a static offset to every created CK_ID.
+		*/
+		const CK_ID c_ObjectIdOffset = 61u;
+		CKDWORD Id2Offset(CK_ID id) { return static_cast<CKDWORD>(id - c_ObjectIdOffset); }
+		CK_ID Offset2Id(CKDWORD off) { return static_cast<CK_ID>(off + c_ObjectIdOffset); }
+
+		/**
+		 * @brief The real CKObject destroy worker shared by CKObjectManager::DestroyObject and CKObjectManager::~CKObjectManager
+		 * @param[in] obj The CKObject need to be free.
+		*/
+		void InternalDestroy(ObjImpls::CKObject* obj);
+
+		CKDWORD m_ObjectCount;
+		XContainer::XObjectPointerArray m_ObjectsList;
+		XContainer::XArray<XContainer::XArray<CKDWORD>> m_ObjectsListByClass;
+		std::deque<CKDWORD> m_ReturnedObjectOffsets;
+
+		XContainer::XObjectPointerArray m_GroupGlobalIndex;
+		XContainer::XObjectPointerArray m_SceneGlobalIndex;
+
+	};
+
+}
diff --git a/LibCmo/CK2/MgrImpls/CKPathManager.cpp b/LibCmo/CK2/MgrImpls/CKPathManager.cpp
new file mode 100644
index 0000000..9525ae7
--- /dev/null
+++ b/LibCmo/CK2/MgrImpls/CKPathManager.cpp
@@ -0,0 +1,6 @@
+#include "CKPathManager.hpp"
+
+namespace LibCmo::CK2::MgrImpls {
+
+}
+
diff --git a/LibCmo/CK2/MgrImpls/CKPathManager.hpp b/LibCmo/CK2/MgrImpls/CKPathManager.hpp
new file mode 100644
index 0000000..675e7d8
--- /dev/null
+++ b/LibCmo/CK2/MgrImpls/CKPathManager.hpp
@@ -0,0 +1,19 @@
+#pragma once
+
+#include "../../VTAll.hpp"
+#include "CKBaseManager.hpp"
+
+namespace LibCmo::CK2::MgrImpls {
+
+	class CKPathManager : public CKBaseManager {
+	public:
+		CKPathManager(CKContext* ctx) :
+			CKBaseManager(ctx, PATH_MANAGER_GUID, "Path Manager") {}
+		virtual ~CKPathManager() {}
+		LIBCMO_DISABLE_COPY_MOVE(CKPathManager);
+
+	protected:
+
+	};
+
+}
diff --git a/LibCmo/CK2/ObjImpls/CKObject.hpp b/LibCmo/CK2/ObjImpls/CKObject.hpp
index ca486d6..fbeb230 100644
--- a/LibCmo/CK2/ObjImpls/CKObject.hpp
+++ b/LibCmo/CK2/ObjImpls/CKObject.hpp
@@ -2,6 +2,37 @@
 
 #include "../../VTAll.hpp"
 
+/**
+CKObject virtual functions implementations help
+
+Implement as original meaning:
+- PreSave()
+- Save()
+- Load()
+- PostLoad()
+
+- GetClassID()
+
+- Show()
+- IsHiddenByParent()
+- CanBeHide()
+- IsVisible()
+
+No implement because don't care:
+- GetMemoryOccupation()
+- IsObjectUsed()
+- PrepareDependencies()
+- RemapDependencies()
+
+- CheckPreDeletion()
+- CheckPostDeletion()
+
+Implement moved into other location:
+- Copy(): Use CKObject::CKObject(CK_ID newid, const CKObject* obj) ctor and CKClassDesc to implement.
+- PreDelete(): Write in dtor.
+
+*/
+
 namespace LibCmo::CK2::ObjImpls {
 
 	class CKObject {
@@ -19,7 +50,7 @@ namespace LibCmo::CK2::ObjImpls {
 			return m_ID;
 		}
 		CKSTRING GetName(void) {
-			return m_Name.c_str();
+			return m_Name.toCKSTRING();
 		}
 		void SetName(CKSTRING u8_name) {
 			m_Name = u8_name;
diff --git a/LibCmo/LibCmo.vcxproj b/LibCmo/LibCmo.vcxproj
index 4668ae9..68ec90b 100644
--- a/LibCmo/LibCmo.vcxproj
+++ b/LibCmo/LibCmo.vcxproj
@@ -180,6 +180,8 @@
     <ClCompile Include="CK2\CKGlobals.cpp" />
     <ClCompile Include="CK2\MgrImpls\CKBaseManager.cpp" />
     <ClCompile Include="CK2\CKContext.cpp" />
+    <ClCompile Include="CK2\MgrImpls\CKObjectManager.cpp" />
+    <ClCompile Include="CK2\MgrImpls\CKPathManager.cpp" />
     <ClCompile Include="CK2\ObjImpls\CK3dEntity.cpp" />
     <ClCompile Include="CK2\ObjImpls\CKBeObject.cpp" />
     <ClCompile Include="CK2\ObjImpls\CKGroup.cpp" />
@@ -203,6 +205,8 @@
     <ClInclude Include="CK2\CKContext.hpp" />
     <ClInclude Include="CK2\CKStateChunk.hpp" />
     <ClInclude Include="CK2\CKTypes.hpp" />
+    <ClInclude Include="CK2\MgrImpls\CKObjectManager.hpp" />
+    <ClInclude Include="CK2\MgrImpls\CKPathManager.hpp" />
     <ClInclude Include="CK2\ObjImpls\CK3dEntity.hpp" />
     <ClInclude Include="CK2\ObjImpls\CK3dObject.hpp" />
     <ClInclude Include="CK2\ObjImpls\CKBeObject.hpp" />
diff --git a/LibCmo/LibCmo.vcxproj.filters b/LibCmo/LibCmo.vcxproj.filters
index 9cbc81c..983e87d 100644
--- a/LibCmo/LibCmo.vcxproj.filters
+++ b/LibCmo/LibCmo.vcxproj.filters
@@ -96,6 +96,12 @@
     <ClCompile Include="CK2\ObjImpls\CK3dEntity.cpp">
       <Filter>Sources\CK2\ObjImpls</Filter>
     </ClCompile>
+    <ClCompile Include="CK2\MgrImpls\CKObjectManager.cpp">
+      <Filter>Sources\CK2\MgrImpls</Filter>
+    </ClCompile>
+    <ClCompile Include="CK2\MgrImpls\CKPathManager.cpp">
+      <Filter>Sources\CK2\MgrImpls</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ClInclude Include="VTUtils.hpp">
@@ -167,5 +173,11 @@
     <ClInclude Include="CK2\ObjImpls\CK3dObject.hpp">
       <Filter>Headers\CK2\ObjImpls</Filter>
     </ClInclude>
+    <ClInclude Include="CK2\MgrImpls\CKObjectManager.hpp">
+      <Filter>Headers\CK2\MgrImpls</Filter>
+    </ClInclude>
+    <ClInclude Include="CK2\MgrImpls\CKPathManager.hpp">
+      <Filter>Headers\CK2\MgrImpls</Filter>
+    </ClInclude>
   </ItemGroup>
 </Project>
\ No newline at end of file
diff --git a/LibCmo/VTUtils.hpp b/LibCmo/VTUtils.hpp
index a26e2c2..def6e87 100644
--- a/LibCmo/VTUtils.hpp
+++ b/LibCmo/VTUtils.hpp
@@ -94,12 +94,26 @@ namespace LibCmo {
 				m_Str = m_HasStr ? cstr : "";
 				return *this;
 			}
+			bool operator==(const char* rhs) const {
+				if (m_HasStr) {
+					return m_Str == rhs;
+				} else {
+					return rhs == nullptr;
+				}
+			}
 			MKString(const std::string& cstr) : m_HasStr(true), m_Str(cstr) {}
 			MKString& operator=(const std::string& cstr) {
 				m_HasStr = true;
 				m_Str = cstr;
 				return *this;
 			}
+			bool operator==(const std::string& rhs) const {
+				if (m_HasStr) {
+					return m_Str == rhs;
+				} else {
+					return false;
+				}
+			}
 
 			MKString(const MKString& rhs) : m_HasStr(rhs.m_HasStr), m_Str(rhs.m_Str) {}
 			MKString(MKString&& rhs) noexcept : m_HasStr(rhs.m_HasStr), m_Str(std::move(rhs.m_Str)) {
@@ -116,13 +130,26 @@ namespace LibCmo {
 				rhs.m_HasStr = false;
 				return *this;
 			}
+			bool operator==(const MKString& rhs) const {
+				return (m_HasStr == rhs.m_HasStr && m_Str == rhs.m_Str);
+			}
 
-			const char* c_str() const {
+			const char* toCKSTRING() const {
 				return m_HasStr ? m_Str.c_str() : nullptr;
 			}
-			const std::string& string() const {
+			/**
+			 * @brief Return the std::string format of this string.
+			 * @remark nullptr string will return blank string.
+			 * @return The std::string format of this string.
+			*/
+			const std::string& toString() const {
 				return m_Str;
 			}
+			/**
+			 * @brief The size of this string.
+			 * @remark Both empty string and nullptr will return 0
+			 * @return The size of this string
+			*/
 			const size_t size() const {
 				return m_HasStr ? m_Str.size() : 0u;
 			}