diff --git a/common/lc_mainwindow.cpp b/common/lc_mainwindow.cpp
index 39174517..3c921ed9 100644
--- a/common/lc_mainwindow.cpp
+++ b/common/lc_mainwindow.cpp
@@ -810,6 +810,41 @@ void lcMainWindow::ColorChanged(int ColorIndex)
 	SetColorIndex(ColorIndex);
 }
 
+void lcMainWindow::ProjectFileChanged(const QString& Path)
+{
+	static bool Ignore;
+
+	if (Ignore)
+		return;
+
+	QString Text = tr("The file '%1' has been modified by another application, do you want to reload it?").arg(Path);
+
+	Ignore = true;
+
+	if (QMessageBox::question(this, tr("File Changed"), Text, QMessageBox::Yes | QMessageBox::No) != QMessageBox::Yes)
+	{
+		Ignore = false;
+		return;
+	}
+
+	Ignore = false;
+
+	Project* NewProject = new Project;
+
+	if (NewProject->Load(Path))
+	{
+		QByteArray TabLayout = SaveTabLayout();
+		gApplication->SetProject(NewProject);
+		RestoreTabLayout(TabLayout);
+		UpdateAllViews();
+	}
+	else
+	{
+		QMessageBox::information(this, tr("LeoCAD"), tr("Error loading '%1'.").arg(Path));
+		delete NewProject;
+	}
+}
+
 void lcMainWindow::Print(QPrinter* Printer)
 {
 #ifndef QT_NO_PRINTER
@@ -1061,6 +1096,177 @@ void lcMainWindow::SetSelectionMode(lcSelectionMode SelectionMode)
 	UpdateSelectionMode();
 }
 
+QByteArray lcMainWindow::SaveTabLayout()
+{
+	QByteArray TabLayout;
+	QDataStream DataStream(&TabLayout, QIODevice::WriteOnly);
+
+	// todo: save version number and focus view
+
+	qint32 NumTabs = mModelTabWidget->count();
+	DataStream << NumTabs;
+	DataStream << ((lcModelTabWidget*)mModelTabWidget->currentWidget())->GetModel()->GetProperties().mName;
+
+	for (int TabIdx = 0; TabIdx < NumTabs; TabIdx++)
+	{
+		lcModelTabWidget* TabWidget = (lcModelTabWidget*)mModelTabWidget->widget(TabIdx);
+
+		DataStream << TabWidget->GetModel()->GetProperties().mName;
+
+		std::function<void (QWidget*)> SaveWidget = [&DataStream, &SaveWidget](QWidget* Widget)
+		{
+			if (Widget->metaObject() == &lcQGLWidget::staticMetaObject)
+			{
+				DataStream << (qint32)0;
+
+				lcCamera* Camera = ((View*)((lcQGLWidget*)Widget)->widget)->mCamera;
+
+				if (Camera->IsSimple())
+				{
+					DataStream << (qint32)0;
+					DataStream << Camera->m_fovy;
+					DataStream << Camera->m_zNear;
+					DataStream << Camera->m_zFar;
+					DataStream << Camera->mPosition;
+					DataStream << Camera->mTargetPosition;
+					DataStream << Camera->mUpVector;
+				}
+				else
+				{
+					DataStream << (qint32)1;
+					DataStream << QByteArray::fromRawData(Camera->m_strName, sizeof(Camera->m_strName));
+				}
+			}
+			else
+			{
+				QSplitter* Splitter = (QSplitter*)Widget;
+
+				DataStream << (qint32)(Splitter->orientation() == Qt::Horizontal ? 1 : 2);
+				DataStream << Splitter->sizes();
+
+				SaveWidget(Splitter->widget(0));
+				SaveWidget(Splitter->widget(1));
+			}
+		};
+
+		QLayout* TabLayout = TabWidget->layout();
+		SaveWidget(TabLayout->itemAt(0)->widget());
+	}
+
+	return TabLayout;
+}
+
+void lcMainWindow::RestoreTabLayout(const QByteArray& TabLayout)
+{
+	QDataStream DataStream(TabLayout);
+
+	qint32 NumTabs;
+	DataStream >> NumTabs;
+	QString CurrentTabName;
+	DataStream >> CurrentTabName;
+
+	RemoveAllModelTabs();
+
+	for (int TabIdx = 0; TabIdx < NumTabs; TabIdx++)
+	{
+		QString ModelName;
+		DataStream >> ModelName;
+
+		lcModel* Model = lcGetActiveProject()->GetModel(ModelName);
+		lcModelTabWidget* TabWidget = nullptr;
+
+		if (Model)
+		{
+			SetCurrentModelTab(Model);
+			TabWidget = (lcModelTabWidget*)mModelTabWidget->widget(mModelTabWidget->count() - 1);
+		}
+
+		std::function<void(QWidget*)> LoadWidget = [&DataStream, &LoadWidget, Model, this](QWidget* ParentWidget)
+		{
+			qint32 WidgetType;
+			DataStream >> WidgetType;
+
+			if (WidgetType == 0)
+			{
+				qint32 CameraType;
+				DataStream >> CameraType;
+
+				View* CurrentView = nullptr;
+				
+				if (ParentWidget)
+					CurrentView = (View*)((lcQGLWidget*)ParentWidget)->widget;
+
+				if (CameraType == 0)
+				{
+					float FoV, ZNear, ZFar;
+					lcVector3 Position, TargetPosition, UpVector;
+
+					DataStream >> FoV;
+					DataStream >> ZNear;
+					DataStream >> ZFar;
+					DataStream >> Position;
+					DataStream >> TargetPosition;
+					DataStream >> UpVector;
+
+					if (CurrentView)
+					{
+						lcCamera* Camera = CurrentView->mCamera;
+						Camera->m_fovy = FoV;
+						Camera->m_zNear = ZNear;
+						Camera->m_zFar = ZFar;
+						Camera->mPosition = Position;
+						Camera->mTargetPosition = TargetPosition;
+						Camera->mUpVector = UpVector;
+						Camera->UpdatePosition(1);
+					}
+				}
+				else
+				{
+					QByteArray CameraName;
+					DataStream >> CameraName;
+
+					if (CurrentView)
+						CurrentView->SetCamera(CameraName);
+				}
+			}
+			else
+			{
+				QList<int> Sizes;
+				DataStream >> Sizes;
+
+				if (ParentWidget)
+				{
+					ParentWidget->setFocus();
+
+					if (WidgetType == 1)
+						SplitVertical();
+					else
+						SplitHorizontal();
+
+					QSplitter* Splitter = (QSplitter*)ParentWidget->parentWidget();
+					Splitter->setSizes(Sizes);
+
+					LoadWidget(Splitter->widget(0));
+					LoadWidget(Splitter->widget(1));
+				}
+				else
+				{
+					LoadWidget(nullptr);
+					LoadWidget(nullptr);
+				}
+			}
+		};
+
+		QLayout* TabLayout = TabWidget->layout();
+		LoadWidget(TabLayout->itemAt(0)->widget());
+	}
+
+	if (!mModelTabWidget->count())
+		lcGetActiveProject()->SetActiveModel(0);
+	else
+		lcGetActiveProject()->SetActiveModel(CurrentTabName);
+}
+
 void lcMainWindow::RemoveAllModelTabs()
 {
 	while (mModelTabWidget->count() > 1)
diff --git a/common/lc_mainwindow.h b/common/lc_mainwindow.h
index 9ac99209..8741cd43 100644
--- a/common/lc_mainwindow.h
+++ b/common/lc_mainwindow.h
@@ -229,6 +229,8 @@ public:
 		return mShadingMenu;
 	}
 
+	QByteArray SaveTabLayout();
+	void RestoreTabLayout(const QByteArray& TabLayout);
 	void RemoveAllModelTabs();
 	void SetCurrentModelTab(lcModel* Model);
 	void ResetCameras();
@@ -300,6 +302,9 @@ public:
 	lcSearchOptions mSearchOptions;
 	QAction* mActions[LC_NUM_COMMANDS];
 
+public slots:
+	void ProjectFileChanged(const QString& Path);
+
 protected slots:
 	void ModelTabClosed(int Index);
 	void ModelTabChanged(int Index);
diff --git a/common/lc_math.h b/common/lc_math.h
index 38f00671..05dc5fb4 100644
--- a/common/lc_math.h
+++ b/common/lc_math.h
@@ -393,6 +393,30 @@ inline QDebug operator<<(QDebug Debug, const lcMatrix44& m)
 
 #endif
 
+inline QDataStream& operator<<(QDataStream& Stream, const lcVector3& v)
+{
+	Stream << v.x << v.y << v.z;
+	return Stream;
+}
+
+inline QDataStream& operator>>(QDataStream& Stream, lcVector3& v)
+{
+	Stream >> v.x >> v.y >> v.z;
+	return Stream;
+}
+
+inline QDataStream& operator<<(QDataStream& Stream, const lcVector4& v)
+{
+	Stream << v.x << v.y << v.z << v.w;
+	return Stream;
+}
+
+inline QDataStream& operator >> (QDataStream& Stream, lcVector4& v)
+{
+	Stream >> v.x >> v.y >> v.z >> v.w;
+	return Stream;
+}
+
 inline void lcVector3::Normalize()
 {
 	float InvLength = 1.0f / Length();
diff --git a/common/project.cpp b/common/project.cpp
index ab02ce24..b3fed79f 100644
--- a/common/project.cpp
+++ b/common/project.cpp
@@ -84,9 +84,7 @@ Project::Project()
 	mActiveModel->SetSaved();
 	mModels.Add(mActiveModel);
 
-#if (QT_VERSION >= QT_VERSION_CHECK(5, 0, 0))
-	QObject::connect(&mFileWatcher, &QFileSystemWatcher::fileChanged, [&](const QString& Path) { Q_UNUSED(Path); FileChanged(); });
-#endif
+	QObject::connect(&mFileWatcher, SIGNAL(fileChanged(const QString&)), gMainWindow, SLOT(ProjectFileChanged(const QString&)));
 }
 
 Project::~Project()
@@ -94,6 +92,15 @@ Project::~Project()
 	mModels.DeleteAll();
 }
 
+lcModel* Project::GetModel(const QString& Name) const
+{
+	for (lcModel* Model : mModels)
+		if (Model->GetProperties().mName == Name)
+			return Model;
+
+	return nullptr;
+}
+
 bool Project::IsModified() const
 {
 	if (mModified)
@@ -159,7 +166,6 @@ void Project::SetActiveModel(const QString& ModelName)
 			return;
 		}
 	}
-
 }
 
 QString Project::GetNewModelName(QWidget* ParentWidget, const QString& DialogTitle, const QString& CurrentName, const QStringList& ExistingModels) const
@@ -331,20 +337,6 @@ void Project::SetFileName(const QString& FileName)
 	mFileName = FileName;
 }
 
-void Project::FileChanged()
-{
-	QString Text = tr("The file '%1' has been modified by another application, do you want to reload it?").arg(mFileName);
-
-	if (QMessageBox::question(gMainWindow, tr("File Changed"), Text, QMessageBox::Yes | QMessageBox::No) != QMessageBox::Yes)
-		return;
-
-	// todo: don't close tabs
-	Load(mFileName);
-	gMainWindow->RemoveAllModelTabs();
-	SetActiveModel(0);
-	lcGetPiecesLibrary()->RemoveTemporaryPieces();
-}
-
 bool Project::Load(const QString& FileName)
 {
 	QFile File(FileName);
diff --git a/common/project.h b/common/project.h
index 63930428..8d3eb3f8 100644
--- a/common/project.h
+++ b/common/project.h
@@ -58,6 +58,8 @@ public:
 		return mModels;
 	}
 
+	lcModel* GetModel(const QString& Name) const;
+
 	lcModel* GetActiveModel() const
 	{
 		return mActiveModel;
@@ -115,7 +117,6 @@ protected:
 	QImage CreatePartsListImage(lcModel* Model, lcStep Step);
 	void CreateHTMLPieceList(QTextStream& Stream, lcModel* Model, lcStep Step, bool Images);
 	void SetFileName(const QString& FileName);
-	void FileChanged();
 
 	bool mModified;
 	QString mFileName;