diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/landscape_editor/builder_zone.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/landscape_editor/builder_zone.cpp
index f9aec3e3b..8e3adf415 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/landscape_editor/builder_zone.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/landscape_editor/builder_zone.cpp
@@ -399,7 +399,7 @@ QString ZoneBuilder::dataPath() const
 bool ZoneBuilder::getZoneMask(sint32 x, sint32 y)
 {
 	if ((x < m_minX) || (x > m_maxX) ||
-		(y < m_minY) || (y > m_maxY))
+			(y < m_minY) || (y > m_maxY))
 		return true;
 	else
 		return m_zoneMask[(x - m_minX) + (y - m_minY) * (1 + m_maxX - m_minX)];
@@ -504,7 +504,7 @@ void ZoneBuilder::checkEndMacro()
 		// Sets list positions in which need apply changes
 		m_undoScanRegionCommand->setScanList(m_zonePositionList);
 		redoScanRegionCommand->setScanList(m_zonePositionList);
-		
+
 		// Adds command in the stack
 		m_undoStack->push(redoScanRegionCommand);
 		m_undoStack->endMacro();
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.cpp
index 05b200960..658231b2c 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.cpp
@@ -178,7 +178,9 @@ Node::NodeType WorldEditNode::type() const
 	return WorldEditNodeType;
 }
 
-LandscapeNode::LandscapeNode(const QString &name)
+LandscapeNode::LandscapeNode(const QString &name, int id)
+	: m_id(id),
+	  m_fileName(name)
 {
 	setData(Qt::DisplayRole, name);
 	setData(Qt::DecorationRole, QIcon(LandscapeEditor::Constants::ICON_ZONE_ITEM));
@@ -188,6 +190,16 @@ LandscapeNode::~LandscapeNode()
 {
 }
 
+QString LandscapeNode::fileName() const
+{
+	return m_fileName;
+}
+
+int LandscapeNode::id() const
+{
+	return m_id;
+}
+
 Node::NodeType LandscapeNode::type() const
 {
 	return LandscapeNodeType;
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.h
index 164ee035f..f95eff0c0 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitive_item.h
@@ -128,12 +128,18 @@ private:
 class LandscapeNode: public Node
 {
 public:
-	LandscapeNode(const QString &name);
+	LandscapeNode(const QString &name, int id);
 	virtual ~LandscapeNode();
 
+	int id() const;
+	QString fileName() const;
+
 	virtual NodeType type() const;
 
 private:
+
+	QString m_fileName;
+	int m_id;
 };
 
 /*
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.cpp
index d40453dee..46436b699 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.cpp
@@ -200,17 +200,29 @@ void PrimitivesTreeModel::deleteWorldEditNode()
 	endResetModel();
 }
 
-Path PrimitivesTreeModel::createLandscapeNode(const QString &fileName)
+bool PrimitivesTreeModel::isWorldEditNodeLoaded() const
+{
+	if (m_worldEditNode == 0)
+		return false;
+	else
+		return true;
+}
+
+Path PrimitivesTreeModel::createLandscapeNode(const QString &fileName, int id, int pos)
 {
 	if (m_worldEditNode == 0)
 		createWorldEditNode("NewWorldEdit");
 
 	QModelIndex parentIndex = index(0, 0, QModelIndex());
-	beginInsertRows(parentIndex, 0, 0);
-	LandscapeNode *newNode = new LandscapeNode(fileName);
-	m_worldEditNode->prependChildNode(newNode);
+	int insPos = pos;
+	if (pos == -1)
+		insPos = 0;
+
+	beginInsertRows(parentIndex, insPos, insPos);
+	LandscapeNode *newNode = new LandscapeNode(fileName, id);
+	m_worldEditNode->insertChildNode(insPos, newNode);
 	endInsertRows();
-	return pathFromIndex(index(0, 0, index(0, 0, QModelIndex())));
+	return pathFromIndex(index(0, 0, index(insPos, 0, QModelIndex())));
 }
 
 
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.h
index c9d59e848..d1a883106 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_model.h
@@ -69,18 +69,17 @@ public:
 	/// Convert QModelIndex to the persistent index - @Path.
 	/// @Path is a list of [row,column] pairs showing us the way through the model.
 	Path pathFromIndex(const QModelIndex &index);
-
-	Path pathFromNode(Node *node);
-
 	QModelIndex pathToIndex(const Path &path);
 
+	Path pathFromNode(Node *node);
 	Node *pathToNode(const Path &path);
 
 	void createWorldEditNode(const QString &fileName);
 	void deleteWorldEditNode();
+	bool isWorldEditNodeLoaded() const;
 
 	/// Add new landscape node in tree model.
-	Path createLandscapeNode(const QString &fileName);
+	Path createLandscapeNode(const QString &fileName, int id, int pos = AtTheEnd);
 
 	/// Add new root primitive node and all sub-primitives in the tree model.
 	Path createRootPrimitiveNode(const QString &fileName, NLLIGO::CPrimitives *primitives, int pos = AtTheEnd);
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.cpp
index b1f5ffda9..6395720c5 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.cpp
@@ -33,6 +33,7 @@
 // Qt includes
 #include <QContextMenuEvent>
 #include <QMessageBox>
+#include <QApplication>
 #include <QtGui/QMenu>
 #include <QtGui/QFileDialog>
 
@@ -49,7 +50,6 @@ PrimitivesView::PrimitivesView(QWidget *parent)
 	setContextMenuPolicy(Qt::DefaultContextMenu);
 
 	m_unloadAction = new QAction("Unload", this);
-	m_unloadAction->setEnabled(false);
 
 	m_saveAction = new QAction("Save", this);
 	m_saveAction->setIcon(QIcon(Core::Constants::ICON_SAVE));
@@ -66,7 +66,6 @@ PrimitivesView::PrimitivesView(QWidget *parent)
 	m_newPrimitiveAction = new QAction("New primitive", this);
 
 	m_deleteAction = new QAction("Delete", this);
-	//m_deleteAction->setEnabled(false);
 
 	m_selectChildrenAction = new QAction("Select children", this);
 
@@ -86,6 +85,9 @@ PrimitivesView::PrimitivesView(QWidget *parent)
 	connect(m_deleteAction, SIGNAL(triggered()), this, SLOT(deletePrimitives()));
 	connect(m_saveAction, SIGNAL(triggered()), this, SLOT(save()));
 	connect(m_saveAsAction, SIGNAL(triggered()), this, SLOT(saveAs()));
+	connect(m_unloadAction, SIGNAL(triggered()), this, SLOT(unload()));
+	connect(m_showAction, SIGNAL(triggered()), this, SLOT(showPrimitive()));
+	connect(m_hideAction, SIGNAL(triggered()), this, SLOT(hidePrimitive()));
 
 #ifdef Q_OS_DARWIN
 	setVerticalScrollMode(QAbstractItemView::ScrollPerPixel);
@@ -186,7 +188,10 @@ void PrimitivesView::selectChildren()
 	QModelIndex parentIndex = indexList.first();
 
 	selectionModel()->clearSelection();
-	selectChildren(parentIndex);
+
+	QItemSelection itemSelection;
+	selectChildren(parentIndex, itemSelection);
+	selectionModel()->select(itemSelection, QItemSelectionModel::Select);
 }
 
 void PrimitivesView::save()
@@ -253,6 +258,41 @@ void PrimitivesView::deletePrimitives()
 
 }
 
+void PrimitivesView::unload()
+{
+	nlassert(m_undoStack);
+	nlassert(m_primitivesTreeModel);
+
+	QModelIndexList indexList = selectionModel()->selectedRows();
+	QModelIndex index = indexList.first();
+	Node *node = static_cast<Node *>(index.internalPointer());
+	switch (node->type())
+	{
+	case Node::WorldEditNodeType:
+	{
+		break;
+	}
+	case Node::LandscapeNodeType:
+	{
+		m_undoStack->push(new UnloadLandscapeCommand(index, m_primitivesTreeModel, m_zoneBuilder));
+		break;
+	}
+	case Node::RootPrimitiveNodeType:
+	{
+		m_undoStack->push(new UnloadRootPrimitiveCommand(index, m_worldEditorScene, m_primitivesTreeModel, this));
+		break;
+	}
+	}
+}
+
+void PrimitivesView::showPrimitive()
+{
+}
+
+void PrimitivesView::hidePrimitive()
+{
+}
+
 void PrimitivesView::addNewPrimitiveByClass(int value)
 {
 	nlassert(m_undoStack);
@@ -311,21 +351,24 @@ void PrimitivesView::contextMenuEvent(QContextMenuEvent *event)
 	event->accept();
 }
 
-void PrimitivesView::selectChildren(const QModelIndex &parent)
+void PrimitivesView::selectChildren(const QModelIndex &parent, QItemSelection &itemSelection)
 {
 	const int rowCount = model()->rowCount(parent);
 
+	QItemSelection mergeItemSelection(parent.child(0, 0), parent.child(rowCount - 1, 0));
+	itemSelection.merge(mergeItemSelection, QItemSelectionModel::Select);
+
 	for (int i = 0; i < rowCount; ++i)
 	{
 		QModelIndex childIndex = parent.child(i, 0);
-		selectionModel()->select(childIndex, QItemSelectionModel::Select);
-		selectChildren(childIndex);
+		if (model()->rowCount(childIndex) != 0)
+			selectChildren(childIndex, itemSelection);
 	}
 }
 
 void PrimitivesView::fillMenu_WorldEdit(QMenu *menu)
 {
-	menu->addAction(m_unloadAction);
+	//menu->addAction(m_unloadAction);
 	//menu->addAction(m_saveAction);
 	//menu->addAction(m_saveAsAction);
 	menu->addSeparator();
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.h
index 3fce65ae7..2b16bc714 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/primitives_view.h
@@ -70,6 +70,9 @@ private Q_SLOTS:
 	void save();
 	void saveAs();
 	void deletePrimitives();
+	void unload();
+	void showPrimitive();
+	void hidePrimitive();
 	void addNewPrimitiveByClass(int value);
 	void generatePrimitives(int value);
 	void openItem(int value);
@@ -78,7 +81,7 @@ protected:
 	void contextMenuEvent(QContextMenuEvent *event);
 
 private:
-	void selectChildren(const QModelIndex &parent);
+	void selectChildren(const QModelIndex &parent, QItemSelection &itemSelection);
 	void fillMenu_WorldEdit(QMenu *menu);
 	void fillMenu_Landscape(QMenu *menu);
 	void fillMenu_RootPrimitive(QMenu *menu, const QModelIndex &index);
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/project_settings_dialog.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/project_settings_dialog.cpp
index 28654864c..42e921106 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/project_settings_dialog.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/project_settings_dialog.cpp
@@ -16,12 +16,14 @@
 
 // Project includes
 #include "project_settings_dialog.h"
+#include "world_editor_misc.h"
 
 #include "../core/icore.h"
 #include "../core/core_constants.h"
 
 // NeL includes
 #include <nel/misc/debug.h>
+#include <nel/ligo/ligo_config.h>
 
 // Qt includes
 #include <QtCore/QSettings>
@@ -36,6 +38,13 @@ ProjectSettingsDialog::ProjectSettingsDialog(const QString &dataPath, QWidget *p
 {
 	m_ui.setupUi(this);
 	m_ui.pathLineEdit->setText(dataPath);
+	m_ui.contextComboBox->addItem("empty");
+
+	// Init the combo box
+	const std::vector<std::string> &contexts = Utils::ligoConfig()->getContextString();
+	for (uint i = 0; i < contexts.size(); i++)
+		m_ui.contextComboBox->addItem(QString(contexts[i].c_str()));
+
 	setFixedHeight(sizeHint().height());
 	connect(m_ui.selectPathButton, SIGNAL(clicked()), this, SLOT(selectPath()));
 }
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.cpp
index 635c7342b..1e27c9f12 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.cpp
@@ -218,7 +218,7 @@ CreateWorldCommand::CreateWorldCommand(const QString &fileName, PrimitivesTreeMo
 	  m_fileName(fileName),
 	  m_model(model)
 {
-	setText("Create new world");
+	setText(QObject::tr("Create new world"));
 }
 
 CreateWorldCommand::~CreateWorldCommand()
@@ -243,7 +243,7 @@ LoadLandscapeCommand::LoadLandscapeCommand(const QString &fileName, PrimitivesTr
 	  m_model(model),
 	  m_zoneBuilder(zoneBuilder)
 {
-	setText("Load land file");
+	setText(QObject::tr("Load land file"));
 }
 
 LoadLandscapeCommand::~LoadLandscapeCommand()
@@ -263,7 +263,41 @@ void LoadLandscapeCommand::redo()
 	else
 		m_zoneBuilder->loadZoneRegion(m_fileName, m_id);
 
-	landIndex = m_model->createLandscapeNode(m_fileName);
+	landIndex = m_model->createLandscapeNode(m_fileName, m_id);
+}
+
+
+UnloadLandscapeCommand::UnloadLandscapeCommand(const QModelIndex &index, PrimitivesTreeModel *model,
+		LandscapeEditor::ZoneBuilderBase *zoneBuilder, QUndoCommand *parent)
+	: QUndoCommand(parent),
+	  m_model(model),
+	  m_zoneBuilder(zoneBuilder)
+{
+	setText(QObject::tr("Unload land file"));
+	m_path = m_model->pathFromIndex(index);
+}
+
+UnloadLandscapeCommand::~UnloadLandscapeCommand()
+{
+}
+
+void UnloadLandscapeCommand::undo()
+{
+	m_zoneBuilder->loadZoneRegion(m_fileName, m_id);
+
+	m_model->createLandscapeNode(m_fileName, m_id, m_path.back().first);
+}
+
+void UnloadLandscapeCommand::redo()
+{
+	QModelIndex index = m_model->pathToIndex(m_path);
+	LandscapeNode *node = static_cast<LandscapeNode *>(index.internalPointer());
+
+	m_id = node->id();
+	m_fileName = node->fileName();
+
+	m_zoneBuilder->deleteZoneRegion(m_id);
+	m_model->deleteNode(m_path);
 }
 
 CreateRootPrimitiveCommand::CreateRootPrimitiveCommand(const QString &fileName, PrimitivesTreeModel *model, QUndoCommand *parent)
@@ -271,7 +305,7 @@ CreateRootPrimitiveCommand::CreateRootPrimitiveCommand(const QString &fileName,
 	  m_fileName(fileName),
 	  m_model(model)
 {
-	setText("Create new primitive");
+	setText(QObject::tr("Create new primitive"));
 }
 
 CreateRootPrimitiveCommand::~CreateRootPrimitiveCommand()
@@ -304,7 +338,7 @@ LoadRootPrimitiveCommand::LoadRootPrimitiveCommand(const QString &fileName, Worl
 	  m_model(model),
 	  m_view(view)
 {
-	setText("Load primitive file");
+	setText(QObject::tr("Load primitive file"));
 }
 
 LoadRootPrimitiveCommand::~LoadRootPrimitiveCommand()
@@ -358,6 +392,47 @@ void LoadRootPrimitiveCommand::redo()
 	addNewGraphicsItems(m_model->pathToIndex(m_rootPrimIndex), m_model, m_scene);
 }
 
+
+UnloadRootPrimitiveCommand::UnloadRootPrimitiveCommand(const QModelIndex &index, WorldEditorScene *scene,
+		PrimitivesTreeModel *model, QTreeView *view, QUndoCommand *parent)
+	: QUndoCommand(parent),
+	  m_scene(scene),
+	  m_model(model),
+	  m_view(view)
+{
+	setText(QObject::tr("Unload primitive file"));
+	m_path = m_model->pathFromIndex(index);
+}
+
+UnloadRootPrimitiveCommand::~UnloadRootPrimitiveCommand()
+{
+}
+
+void UnloadRootPrimitiveCommand::undo()
+{
+	// Disable edit points mode
+	m_scene->setEnabledEditPoints(false);
+
+	m_path = m_model->createRootPrimitiveNode(m_fileName, m_primitives, m_path.back().first);
+
+	addNewGraphicsItems(m_model->pathToIndex(m_path), m_model, m_scene);
+}
+
+void UnloadRootPrimitiveCommand::redo()
+{
+	m_scene->setEnabledEditPoints(false);
+
+	m_view->selectionModel()->clearSelection();
+	QModelIndex index = m_model->pathToIndex(m_path);
+	RootPrimitiveNode *node = static_cast<RootPrimitiveNode *>(index.internalPointer());
+	m_fileName = node->fileName();
+	m_primitives = node->primitives();
+
+	removeGraphicsItems(index, m_model, m_scene);
+
+	m_model->deleteNode(m_path);
+}
+
 AddPrimitiveByClassCommand::AddPrimitiveByClassCommand(const QString &className, const Path &parentIndex,
 		WorldEditorScene *scene, PrimitivesTreeModel *model, QTreeView *view, QUndoCommand *parent)
 	: QUndoCommand(parent),
@@ -367,7 +442,7 @@ AddPrimitiveByClassCommand::AddPrimitiveByClassCommand(const QString &className,
 	  m_model(model),
 	  m_view(view)
 {
-	setText(QString("Add %1").arg(m_className));
+	setText(QObject::tr("Add %1").arg(m_className));
 
 	QGraphicsView *graphicsView = m_scene->views().first();
 
@@ -437,7 +512,7 @@ DeletePrimitiveCommand::DeletePrimitiveCommand(const QModelIndex &index, Primiti
 	  m_model(model),
 	  m_view(view)
 {
-	setText("Delete primitive");
+	setText(QObject::tr("Delete primitive"));
 
 	// Save path to primitive
 	m_path = m_model->pathFromIndex(index);
@@ -629,7 +704,7 @@ MoveWorldItemsCommand::MoveWorldItemsCommand(const QList<QGraphicsItem *> &items
 	: AbstractWorldItemCommand(items, scene, model, parent),
 	  m_offset(offset)
 {
-	setText("Move item(s)");
+	setText(QObject::tr("Move item(s)"));
 }
 
 MoveWorldItemsCommand::~MoveWorldItemsCommand()
@@ -652,7 +727,7 @@ RotateWorldItemsCommand::RotateWorldItemsCommand(const QList<QGraphicsItem *> &i
 	  m_angle(angle),
 	  m_pivot(pivot)
 {
-	setText("Rotate item(s)");
+	setText(QObject::tr("Rotate item(s)"));
 }
 
 RotateWorldItemsCommand::~RotateWorldItemsCommand()
@@ -675,7 +750,7 @@ ScaleWorldItemsCommand::ScaleWorldItemsCommand(const QList<QGraphicsItem *> &ite
 	  m_factor(factor),
 	  m_pivot(pivot)
 {
-	setText("Scale item(s)");
+	setText(QObject::tr("Scale item(s)"));
 }
 
 ScaleWorldItemsCommand::~ScaleWorldItemsCommand()
@@ -698,7 +773,7 @@ TurnWorldItemsCommand::TurnWorldItemsCommand(const QList<QGraphicsItem *> &items
 	: AbstractWorldItemCommand(items, scene, model, parent),
 	  m_angle(angle)
 {
-	setText("Turn item(s)");
+	setText(QObject::tr("Turn item(s)"));
 }
 
 TurnWorldItemsCommand::~TurnWorldItemsCommand()
@@ -722,7 +797,7 @@ ShapeWorldItemsCommand::ShapeWorldItemsCommand(const QList<QGraphicsItem *> &ite
 	  m_redoPolygons(polygons),
 	  m_undoPolygons(polygonsFromItems(items))
 {
-	setText("Change shape");
+	setText(QObject::tr("Change shape"));
 }
 
 ShapeWorldItemsCommand::~ShapeWorldItemsCommand()
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.h
index 15a553822..89de14e9a 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_actions.h
@@ -95,6 +95,34 @@ private:
 	LandscapeEditor::ZoneBuilderBase *const m_zoneBuilder;
 };
 
+/**
+@class UnloadLandscapeCommand
+@brief
+@details
+*/
+class UnloadLandscapeCommand: public QUndoCommand
+{
+public:
+	UnloadLandscapeCommand(const QModelIndex &index, PrimitivesTreeModel *model,
+						   LandscapeEditor::ZoneBuilderBase *zoneBuilder, QUndoCommand *parent = 0);
+	virtual ~UnloadLandscapeCommand();
+
+	virtual void undo();
+	virtual void redo();
+private:
+
+	Path m_path;
+	int m_id;
+	QString m_fileName;
+	PrimitivesTreeModel *const m_model;
+	LandscapeEditor::ZoneBuilderBase *const m_zoneBuilder;
+};
+
+/**
+@class CreateRootPrimitiveCommand
+@brief
+@details
+*/
 class CreateRootPrimitiveCommand: public QUndoCommand
 {
 public:
@@ -112,7 +140,7 @@ private:
 };
 
 /**
-@class LoadPrimitiveCommand
+@class LoadRootPrimitiveCommand
 @brief
 @details
 */
@@ -136,7 +164,32 @@ private:
 };
 
 /**
-@class AddPrimitiveCommand
+@class UnloadRootPrimitiveCommand
+@brief
+@details
+*/
+class UnloadRootPrimitiveCommand: public QUndoCommand
+{
+public:
+	UnloadRootPrimitiveCommand(const QModelIndex &index, WorldEditorScene *scene,
+							   PrimitivesTreeModel *model, QTreeView *view,
+							   QUndoCommand *parent = 0);
+	virtual ~UnloadRootPrimitiveCommand();
+
+	virtual void undo();
+	virtual void redo();
+private:
+
+	Path m_path;
+	QString m_fileName;
+	NLLIGO::CPrimitives *m_primitives;
+	WorldEditorScene *const m_scene;
+	PrimitivesTreeModel *const m_model;
+	QTreeView *m_view;
+};
+
+/**
+@class AddPrimitiveByClassCommand
 @brief
 @details
 */
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.cpp
index 967f6651d..944372735 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.cpp
@@ -67,6 +67,8 @@ AbstractWorldItem *WorldEditorScene::addWorldItemPoint(const QPointF &point, con
 {
 	WorldItemPoint *item = new WorldItemPoint(point, angle, radius, showArrow);
 	addItem(item);
+
+	m_worldItems.push_back(item);
 	return item;
 }
 
@@ -74,6 +76,8 @@ AbstractWorldItem *WorldEditorScene::addWorldItemPath(const QPolygonF &polyline,
 {
 	WorldItemPath *item = new WorldItemPath(polyline);
 	addItem(item);
+
+	m_worldItems.push_back(item);
 	return item;
 }
 
@@ -81,6 +85,8 @@ AbstractWorldItem *WorldEditorScene::addWorldItemZone(const QPolygonF &polygon)
 {
 	WorldItemZone *item = new WorldItemZone(polygon);
 	addItem(item);
+
+	m_worldItems.push_back(item);
 	return item;
 }
 
@@ -90,6 +96,10 @@ void WorldEditorScene::removeWorldItem(QGraphicsItem *item)
 	m_selectedItems.clear();
 	m_editedSelectedItems = false;
 	m_firstSelection = false;
+
+	// TODO
+	AbstractWorldItem *worldItem = qgraphicsitem_cast<AbstractWorldItem *>(item);
+	m_worldItems.removeOne(worldItem);
 	delete item;
 }
 
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.h
index c9da223a7..e981a703e 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene.h
@@ -34,8 +34,8 @@ class AbstractWorldItem;
 
 /*
 @class WorldEditorScene
-@brief
-@details
+@brief The WorldEditorScene provides a surface for managing a large number of 2D world items(point/path/zone).
+@details WorldEditorScene also provides 'selections model' functionality, which differs from standart selection model.
 */
 class WORLD_EDITOR_EXPORT WorldEditorScene : public LandscapeEditor::LandscapeSceneBase
 {
@@ -56,22 +56,38 @@ public:
 					 QUndoStack *undoStack, QObject *parent = 0);
 	virtual ~WorldEditorScene();
 
+	/// Create WorldItemPoint and add in scene.
 	AbstractWorldItem *addWorldItemPoint(const QPointF &point, const qreal angle,
 										 const qreal radius, bool showArrow);
+
+	/// Create WorldItemPath and add in scene.
 	AbstractWorldItem *addWorldItemPath(const QPolygonF &polyline, bool showArrow);
+
+	/// Create WorldItemZone and add in scene.
 	AbstractWorldItem *addWorldItemZone(const QPolygonF &polygon);
+
+	/// Remove a world item from the scene.
 	void removeWorldItem(QGraphicsItem *item);
 
+	/// Set current mode editing(select/move/rotate/scale/turn), above world items.
 	void setModeEdit(WorldEditorScene::ModeEdit mode);
+
 	WorldEditorScene::ModeEdit editMode() const;
 
+	/// @return true if edit points mode is enabled, else false.
 	bool isEnabledEditPoints() const;
 
 Q_SIGNALS:
+	/// This signal is emitted by WorldEditorScene when the selections changes.
+	/// The @selected value contains a list of all selected items.
 	void updateSelectedItems(const QList<QGraphicsItem *> &selected);
 
 public Q_SLOTS:
+	/// Enable/disable edit points mode (user can change shape of WorldItemZone and WorldItemPath)
+	///
 	void setEnabledEditPoints(bool enabled);
+
+	/// Update of selections
 	void updateSelection(const QList<QGraphicsItem *> &selected, const QList<QGraphicsItem *> &deselected);
 
 protected:
@@ -102,6 +118,7 @@ private:
 	qreal m_firstPickX, m_firstPickY, m_angle;
 	QList<QGraphicsItem *> m_selectedItems;
 	QList<QGraphicsItem *> m_selectedPoints;
+	QList<AbstractWorldItem *> m_worldItems;
 	QList<QPolygonF> m_polygons;
 	bool m_editedSelectedItems, m_firstSelection;
 	uint m_lastPickedPrimitive;
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene_item.h b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene_item.h
index 7268b6d03..9136712c5 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene_item.h
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_scene_item.h
@@ -53,8 +53,8 @@ const int EDGE_POINT_LAYER = 201;
 const int SIZE_ARROW = 20;
 
 /*
-@class WorldItemPoint
-@brief
+@class AbstractWorldItem
+@brief Abstract class for graphics item
 @details
 */
 class AbstractWorldItem: public QGraphicsItem
@@ -65,13 +65,21 @@ public:
 
 	enum { Type = QGraphicsItem::UserType + 1 };
 
+	/// Rotate item around @pivot point on &deltaAngle (deg).
 	virtual void rotateOn(const QPointF &pivot, const qreal deltaAngle) {};
+
+	/// Scales item relatively @pivot point
 	// TODO: add modes: IgnoreAspectRatio, KeepAspectRatio
 	virtual void scaleOn(const QPointF &pivot, const QPointF &factor) {};
+
+	/// Rotate arrow on angle (deg). (only for WorldItemPoint)
 	virtual void turnOn(const qreal angle) {};
 	virtual void radiusOn(const qreal radius) {};
 
+	/// Change color
 	virtual void setColor(const QColor &color) = 0;
+
+	/// Enable/disable the mode edit shape (only for WorldItemPath and WorldItemPath)
 	virtual void setEnabledSubPoints(bool enabled) = 0;
 
 	virtual void moveSubPoint(WorldItemSubPoint *subPoint) {}
@@ -103,7 +111,8 @@ protected:
 
 /*
 @class WorldItemPoint
-@brief
+@brief WorldItemPoint class provides a dot item with arrow and circle(@radius)
+that you can add to a WorldEditorScene.
 @details
 */
 class WorldItemPoint: public AbstractWorldItem
@@ -148,7 +157,7 @@ private:
 
 /*
 @class WorldItemPath
-@brief
+@brief WorldItemPath class provides a polyline item that you can add to a WorldEditorScene.
 @details
 */
 class WorldItemPath: public AbstractWorldItem
@@ -188,7 +197,7 @@ private:
 
 /*
 @class WorldItemZone
-@brief
+@brief The WorldItemZone class provides a polygon item that you can add to a WorldEditorScene.
 @details
 */
 class WorldItemZone: public AbstractWorldItem
diff --git a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_window.cpp b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_window.cpp
index ba5543776..b2691fba3 100644
--- a/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_window.cpp
+++ b/code/nel/tools/3d/object_viewer_qt/src/plugins/world_editor/world_editor_window.cpp
@@ -165,6 +165,9 @@ void WorldEditorWindow::open()
 
 void WorldEditorWindow::loadWorldEditFile(const QString &fileName)
 {
+	if (m_primitivesModel->isWorldEditNodeLoaded())
+		return;
+
 	Utils::WorldEditList worldEditList;
 	if (!Utils::loadWorldEditFile(fileName.toStdString(), worldEditList))
 	{