not working yet

CMakeLists.txt

@@ -19,6 +19,18 @@ endif()
 
 project(uLib)
 
+option(ULIB_USE_CCACHE "Use ccache for build acceleration" ON)
+if(ULIB_USE_CCACHE)
+    find_program(CCACHE_PROGRAM ccache)
+    if(CCACHE_PROGRAM)
+        set(CMAKE_CXX_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+        set(CMAKE_C_COMPILER_LAUNCHER "${CCACHE_PROGRAM}")
+    endif()
+else()
+    set(CMAKE_CXX_COMPILER_LAUNCHER "")
+    set(CMAKE_C_COMPILER_LAUNCHER "")
+endif()
+
 # Applica la flag SOLO se il compilatore è GCC
 if(CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
     add_compile_options(-fno-merge-constants)
@@ -130,8 +142,11 @@ find_package(Boost 1.45.0 COMPONENTS program_options serialization unit_test_fra
 include_directories(${Boost_INCLUDE_DIRS})
 
 find_package(Eigen3 CONFIG REQUIRED)
-get_target_property(EIGEN3_INCLUDE_DIRS Eigen3::Eigen INTERFACE_INCLUDE_DIRECTORIES)
+# if(NOT EIGEN3_INCLUDE_DIRS)
-include_directories(${EIGEN3_INCLUDE_DIRS})
+#     get_target_property(EIGEN3_INCLUDE_DIRS Eigen3::Eigen INTERFACE_INCLUDE_DIRECTORIES)
+# else()
+#     include_directories(${EIGEN3_INCLUDE_DIRS})
+# endif()
 
 find_package(OpenMP)
 

app/gcompose/CMakeLists.txt

@@ -17,6 +17,8 @@ add_executable(gcompose
     src/PropertyWidgets.cpp
     src/PropertiesPanel.h
     src/PropertiesPanel.cpp
+    src/PreferencesDialog.h
+    src/PreferencesDialog.cpp
 )
 
 set_target_properties(gcompose PROPERTIES

app/gcompose/src/ContextModel.cpp

@@ -148,6 +148,7 @@ QVariant ContextModel::data(const QModelIndex& index, int role) const {
     if (!index.isValid()) return QVariant();
 
     uLib::Object* obj = static_cast<uLib::Object*>(index.internalPointer());
+    if (!obj) return QVariant();
     
     if (role == Qt::DisplayRole) {
         QString typeName = getDemangledName(typeid(*obj));

app/gcompose/src/MainPanel.cpp

@@ -13,11 +13,14 @@
 #include <QPushButton>
 #include <QMenu>
 #include <QAction>
+#include <QShortcut>
 #include <QApplication>
 #include <QFileDialog>
 #include <QFileInfo>
 #include "StyleManager.h"
 #include "Math/VoxImage.h"
+#include "PreferencesDialog.h"
+#include "Settings.h"
 
 MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_mainVtkContext(nullptr) {
     this->setObjectName("MainPanel");
@@ -45,17 +48,12 @@ MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_m
     fileMenu->addAction("Open", this, &MainPanel::onOpen);
     fileMenu->addAction("Save", this, &MainPanel::onSave);
     fileMenu->addAction("Save As", this, &MainPanel::onSaveAs);
+    fileMenu->addSeparator();
+    fileMenu->addAction("Preferences", this, &MainPanel::onPreferences);
+    fileMenu->addSeparator();
     fileMenu->addAction("Exit", this, &MainPanel::onExit);
     btnFile->setMenu(fileMenu);
 
-    // Theme Menu Button
-    auto* btnTheme = new QPushButton("Theme", menuPanel);
-    btnTheme->setObjectName("MenuButton");
-    auto* themeMenu = new QMenu(btnTheme);
-    themeMenu->addAction("Dark", this, &MainPanel::onDarkTheme);
-    themeMenu->addAction("Bright", this, &MainPanel::onBrightTheme);
-    btnTheme->setMenu(themeMenu);
-
     // New Menu Button
     auto* btnNew = new QPushButton("Add", menuPanel);
     btnNew->setObjectName("MenuButton");
@@ -73,7 +71,6 @@ MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_m
     menuLayout->addWidget(logo);
     menuLayout->addWidget(btnFile);
     menuLayout->addWidget(btnNew);
-    menuLayout->addWidget(btnTheme);
     menuLayout->addStretch();
 
     mainLayout->addWidget(menuPanel);
@@ -108,6 +105,14 @@ MainPanel::MainPanel(QWidget* parent) : QWidget(parent), m_context(nullptr), m_m
     m_rootSplitter->setSizes(sizes);
 
     mainLayout->addWidget(m_rootSplitter, 1);
+    
+    // Shortcuts
+    auto* groupShortcut = new QShortcut(QKeySequence("Ctrl+G"), this);
+    connect(groupShortcut, &QShortcut::activated, [this]() {
+        if (auto* viewport = qobject_cast<uLib::Vtk::QViewport*>(m_firstPane->currentViewport())) {
+            viewport->GroupSelection(m_context);
+        }
+    });
 }
 
 void MainPanel::setContext(uLib::ObjectsContext* context) {
@@ -236,12 +241,21 @@ void MainPanel::onExit() {
     qApp->quit();
 }
 
-void MainPanel::onDarkTheme() {
+void MainPanel::onPreferences() {
-    StyleManager::applyStyle(qApp, "dark");
+    uLib::Qt::PreferencesDialog dlg(this);
-}
+    if (dlg.exec() == QDialog::Accepted) {
+        // Apply theme
+        auto theme = uLib::Qt::Settings::Instance().GetTheme();
+        StyleManager::applyStyle(qApp, theme == uLib::Qt::Settings::Dark ? "dark" : "bright");
 
-void MainPanel::onBrightTheme() {
+        // Apply rendering preference to all viewports
-    StyleManager::applyStyle(qApp, "bright");
+        bool throttled = uLib::Qt::Settings::Instance().GetThrottledRendering();
+        auto viewports = this->findChildren<uLib::Vtk::QViewport*>();
+        for (auto* vp : viewports) {
+            vp->SetThrottledRendering(throttled);
+            vp->Render();
+        }
+    }
 }
 
 MainPanel::~MainPanel() {}

app/gcompose/src/MainPanel.h

@@ -30,8 +30,7 @@ private slots:
     void onSaveAs();
     void onExit();
 
-    void onDarkTheme();
+    void onPreferences();
-    void onBrightTheme();
     
     void onCreateObject(const std::string& className);
 

app/gcompose/src/PreferencesDialog.cpp

@@ -0,0 +1,99 @@
+#include "PreferencesDialog.h"
+#include <QVBoxLayout>
+#include <QHBoxLayout>
+#include <QFormLayout>
+#include <QPushButton>
+#include <QLabel>
+#include <QGroupBox>
+
+namespace uLib {
+namespace Qt {
+
+PreferencesDialog::PreferencesDialog(QWidget* parent) : QDialog(parent) {
+    setWindowTitle("Preferences");
+    setMinimumWidth(400);
+    
+    auto* mainLayout = new QVBoxLayout(this);
+    mainLayout->setSpacing(20);
+    mainLayout->setContentsMargins(20, 20, 20, 20);
+
+    // ── General / Rendering Settings ────────────────────────────────────────
+    auto* renderingGroup = new QGroupBox("Appearance & Performance", this);
+    auto* renderingLayout = new QVBoxLayout(renderingGroup);
+    
+    auto* themeLayout = new QHBoxLayout();
+    themeLayout->addWidget(new QLabel("Color Theme:"));
+    m_themeCombo = new QComboBox(renderingGroup);
+    m_themeCombo->addItem("Dark");
+    m_themeCombo->addItem("Bright");
+    m_themeCombo->setCurrentIndex(Settings::Instance().GetTheme() == Settings::Dark ? 0 : 1);
+    themeLayout->addWidget(m_themeCombo);
+    themeLayout->addStretch();
+    
+    renderingLayout->addLayout(themeLayout);
+    renderingLayout->addSpacing(10);
+
+    m_throttledRendering = new QCheckBox("Enable throttled rendering (recommended for performance)", renderingGroup);
+    m_throttledRendering->setChecked(Settings::Instance().GetThrottledRendering());
+    m_throttledRendering->setToolTip("Limits framerate to ~60fps to reduce CPU/GPU usage.");
+    
+    renderingLayout->addWidget(m_throttledRendering);
+    mainLayout->addWidget(renderingGroup);
+
+    // ── Units Settings ──────────────────────────────────────────────────────
+    auto* unitsGroup = new QGroupBox("Preferred Units", this);
+    auto* unitsLayout = new QFormLayout(unitsGroup);
+    unitsLayout->setLabelAlignment(::Qt::AlignRight);
+    unitsLayout->setSpacing(10);
+
+    auto addUnitRow = [&](const QString& label, Settings::Dimension dim, const QStringList& units) {
+        auto* combo = new QComboBox(unitsGroup);
+        combo->addItems(units);
+        std::string current = Settings::Instance().GetPreferredUnit(dim);
+        int idx = combo->findText(QString::fromStdString(current));
+        if (idx >= 0) combo->setCurrentIndex(idx);
+        
+        unitsLayout->addRow(label + ":", combo);
+        m_unitCombos[dim] = combo;
+    };
+
+    addUnitRow("Length", Settings::Length, {"m", "cm", "mm", "um", "nm"});
+    addUnitRow("Angle", Settings::Angle, {"deg", "rad"});
+    addUnitRow("Energy", Settings::Energy, {"MeV", "GeV", "eV", "keV", "TeV"});
+    addUnitRow("Time", Settings::Time, {"ns", "s", "ms", "us"});
+
+    mainLayout->addWidget(unitsGroup);
+
+    mainLayout->addStretch();
+
+    // ── Buttons ─────────────────────────────────────────────────────────────
+    auto* buttonLayout = new QHBoxLayout();
+    buttonLayout->addStretch();
+    
+    auto* btnCancel = new QPushButton("Cancel", this);
+    connect(btnCancel, &QPushButton::clicked, this, &QDialog::reject);
+    
+    auto* btnOk = new QPushButton("Apply", this);
+    btnOk->setDefault(true);
+    btnOk->setObjectName("DisplayToggleBtn"); // Reusing high-contrast style
+    btnOk->setMinimumWidth(100);
+    connect(btnOk, &QPushButton::clicked, this, &PreferencesDialog::onAccept);
+    
+    buttonLayout->addWidget(btnCancel);
+    buttonLayout->addWidget(btnOk);
+    mainLayout->addLayout(buttonLayout);
+}
+
+void PreferencesDialog::onAccept() {
+    Settings::Instance().SetThrottledRendering(m_throttledRendering->isChecked());
+    Settings::Instance().SetTheme(m_themeCombo->currentIndex() == 0 ? Settings::Dark : Settings::Bright);
+    
+    for (auto const& pair : m_unitCombos) {
+        Settings::Instance().SetPreferredUnit(pair.first, pair.second->currentText().toStdString());
+    }
+    
+    accept();
+}
+
+} // namespace Qt
+} // namespace uLib

app/gcompose/src/PreferencesDialog.h

@@ -0,0 +1,31 @@
+#ifndef GCOMPOSE_PREFERENCESDIALOG_H
+#define GCOMPOSE_PREFERENCESDIALOG_H
+
+#include <QDialog>
+#include <QCheckBox>
+#include <QComboBox>
+#include <map>
+#include <string>
+#include "Settings.h"
+
+namespace uLib {
+namespace Qt {
+
+class PreferencesDialog : public QDialog {
+    Q_OBJECT
+public:
+    explicit PreferencesDialog(QWidget* parent = nullptr);
+
+private slots:
+    void onAccept();
+
+private:
+    QCheckBox* m_throttledRendering;
+    QComboBox* m_themeCombo;
+    std::map<Settings::Dimension, QComboBox*> m_unitCombos;
+};
+
+} // namespace Qt
+} // namespace uLib
+
+#endif

app/gcompose/src/QViewportPane.cpp

@@ -94,8 +94,8 @@ void QViewportPane::setObject(uLib::Object* obj) {
 
 void QViewportPane::setViewport(QWidget* viewport, const QString& title) {
     if (m_viewport) {
-        m_viewport->parentWidget()->layout()->removeWidget(m_viewport);
+        // Use deleteLater() instead of delete to avoid crashes during repaint cycles
-        delete m_viewport;
+        m_viewport->deleteLater();
     }
     m_viewport = viewport;
     m_titleLabel->setText(title);
@@ -105,21 +105,8 @@ void QViewportPane::setViewport(QWidget* viewport, const QString& title) {
     mainAreaLayout->insertWidget(0, m_viewport);
 }
 
-
 QViewportPane::~QViewportPane() {}
 
-void QViewportPane::setViewport(QWidget* viewport, const QString& title) {
-    if (m_viewport) {
-        m_layout->removeWidget(m_viewport);
-        delete m_viewport;
-    }
-    m_viewport = viewport;
-    m_titleLabel->setText(title);
-
-    m_viewport->setSizePolicy(QSizePolicy::Expanding, QSizePolicy::Expanding);
-    m_layout->addWidget(m_viewport);
-}
-
 void QViewportPane::addVtkViewport() {
     auto* viewport = new uLib::Vtk::QViewport(this);
     setViewport(viewport, "VTK Viewport");

app/gcompose/src/Settings.h

@@ -23,6 +23,11 @@ public:
         Dimensionless
     };
 
+    enum Theme {
+        Dark,
+        Bright
+    };
+
     void SetPreferredUnit(Dimension dim, const std::string& unit) {
         m_PreferredUnits[dim] = unit;
     }
@@ -64,9 +69,17 @@ public:
         return Dimensionless;
     }
 
+    bool GetThrottledRendering() const { return m_ThrottledRendering; }
+    void SetThrottledRendering(bool enabled) { m_ThrottledRendering = enabled; }
+
+    Theme GetTheme() const { return m_Theme; }
+    void SetTheme(Theme theme) { m_Theme = theme; }
+
 private:
-    Settings() {}
+    Settings() : m_ThrottledRendering(true), m_Theme(Dark) {}
     std::map<Dimension, std::string> m_PreferredUnits;
+    bool m_ThrottledRendering;
+    Theme m_Theme;
 };
 
 } // namespace Qt

app/gcompose/src/ViewportPane.cpp

@@ -115,7 +115,7 @@ void ViewportPane::setObject(uLib::Object* obj) {
 
 void ViewportPane::setViewport(QWidget* viewport, const QString& title) {
     if (m_viewport) {
-        delete m_viewport;
+        m_viewport->deleteLater();
     }
     m_viewport = viewport;
     m_titleLabel->setText(title);

build.log

@@ -1,36 +1 @@
-make: Entering directory '/home/rigoni/devel/cmt/ulib/build'
+ninja: error: loading 'build.ninja': No such file or directory
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/VoxImage.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/TriangleMesh.cpp.o
-[ 30%] Building CXX object src/Core/CMakeFiles/mutomCore.dir/Options.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/Dense.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/StructuredGrid.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/VoxRaytracer.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/StructuredData.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/Structured2DGrid.cpp.o
-[ 30%] Building CXX object src/Math/CMakeFiles/mutomMath.dir/Structured4DGrid.cpp.o
-[ 33%] Linking CXX shared library libmutomCore.so
-[ 33%] Built target mutomCore
-[ 36%] Linking CXX shared library libmutomMath.so
-[ 36%] Built target mutomMath
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/vtkContainerBox.cpp.o
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/uLibVtkInterface.cxx.o
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/vtkStructuredGrid.cpp.o
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/vtkMuonScatter.cxx.o
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/uLibVtkViewer.cpp.o
-[ 63%] Generating mutomRootDict.cxx, libmutomRootDict_rdict.pcm, libmutomRootDict.rootmap
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/vtkVoxImage.cpp.o
-[ 63%] Building CXX object src/Vtk/CMakeFiles/mutomVtk.dir/vtkVoxRaytracerRepresentation.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorSkinHit.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorHit.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorMCTrack.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorInfo.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/RootMuonScatter.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorPrimaryVertex.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/muCastorMuDetDIGI.cpp.o
-[ 90%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/SkinDetectorWriter.cpp.o
-[ 93%] Building CXX object src/Root/CMakeFiles/mutomRoot.dir/mutomRootDict.cxx.o
-[ 96%] Linking CXX shared library libmutomVtk.so
-[ 96%] Built target mutomVtk
-[100%] Linking CXX shared library libmutomRoot.so
-[100%] Built target mutomRoot
-make: Leaving directory '/home/rigoni/devel/cmt/ulib/build'

conanfile.txt

@@ -1,5 +1,5 @@
 [requires]
-eigen/3.4.0
+# eigen/5.0.1
 boost/1.86.0
 # pybind11/3.0.2
 hdf5/1.14.3

condaenv.yml

@@ -9,7 +9,7 @@ dependencies:
   - root
   - vtk=9.4 # VTK 9.4
   - pybind11
-#  - boost=1.86.0 # requested by VTK 9.4
+  #- boost=1.86.0 # requested by VTK 9.4
   - ninja
   - clang
   - clangxx

docs/code/vtk/vtk_Prop3D.md

@@ -0,0 +1,48 @@
+# Prop3D
+
+`uLib::Vtk::Prop3D` is a bridge class that wraps VTK 3D representations (`vtkProp`, `vtkProp3D`) and integrates them into the `uLib` object model. It allows the framework to manage visual objects, synchronize them with underlying data models, and expose display-specific properties to the GUI.
+
+## Inheritance
+`uLib::Vtk::Prop3D` : `uLib::Object`
+
+## Key Functionalities
+
+### VTK Integration
+The class provides access to the underlying VTK objects:
+- `GetProp()`: Returns the `vtkProp`.
+- `GetProxyProp()`: Returns the `vtkProp3D`.
+- `GetParts()` / `GetProps()`: Returns `vtkPropCollection` for composite objects.
+
+### Model-View Synchronization
+`Prop3D` ensures that the visual representation stays in sync with the domain model:
+- `Update()`: Synchronizes the VTK representation based on current internal state and properties. Should be called when model data changes.
+- `SyncFromVtk()`: Updates internal state using data from the VTK representation (e.g., after user interaction via gizmos in the 3D view).
+- `GetContent()`: Returns the `uLib::Object` that this `Prop3D` represents visually.
+
+### Visual Appearance
+- **Color & Opacity**: `SetColor(r, g, b)` and `SetOpacity(alpha)`.
+- **Selection**: `SetSelectable(bool)` and `SetSelected(bool)` to manage interactivity and highlighting.
+- **BBox/Scale**: `ShowBoundingBox(bool)` and `ShowScaleMeasures(bool)`.
+
+### Rendering Modes
+The rendering style can be controlled via the `Representation` enum:
+- `Points`
+- `Wireframe`
+- `Surface`
+- `SurfaceWithEdges`
+- `Volume`
+- `Outline`
+- `Slice`
+
+### Display Properties System
+`Prop3D` implements a system to expose specific properties (often marked as `hrp` - human readable properties) to a property editor in the GUI.
+
+- `GetDisplayProperties()`: Returns the list of properties registered for display.
+- `RegisterDisplayProperty(uLib::PropertyBase*)`: Adds a property to the display list.
+- `serialize_display(...)`: A virtual method that subclasses implement to define which properties should be exposed.
+
+#### Activating Display Properties
+To automatically populate the display properties list, the `ULIB_ACTIVATE_DISPLAY_PROPERTIES` macro should be called in the constructor. This triggers `serialize_display` using a `display_properties_archive`.
+
+## Implementation Details
+`Prop3D` uses the Pimpl idiom (via `Prop3DData *pd`) to hide VTK-specific implementation details and reduce header dependencies.

src/Core/DataAllocator.h

@@ -46,6 +46,8 @@ public:
   DataAllocator(size_t size = 0, bool owns_objects = true)
       : m_Size(size), m_RamData(nullptr), m_VramData(nullptr),
         m_Device(MemoryDevice::RAM), m_OwnsObjects(owns_objects) {
+    if (m_Size >= (static_cast<size_t>(1) << 60))
+        throw std::invalid_argument("DataAllocator: absurdly large size requested");
     if (m_Size > 0) {
       if (m_OwnsObjects)
         m_RamData = new T[m_Size]();
@@ -139,7 +141,7 @@ public:
   void MoveToRAM() {
     if (m_Device == MemoryDevice::RAM)
       return;
-    if (!m_RamData && m_Size > 0) {
+    if (!m_RamData && m_Size > 0 && m_Size < (static_cast<size_t>(1) << 60)) {
       if (m_OwnsObjects)
         m_RamData = new T[m_Size]();
       else
@@ -178,7 +180,7 @@ public:
     T *newRam = nullptr;
     T *newVram = nullptr;
 
-    if (size > 0) {
+    if (size > 0 && size < (static_cast<size_t>(1) << 60)) {
       if (m_OwnsObjects)
         newRam = new T[size]();
       else

src/Core/Object.cpp

@@ -60,6 +60,10 @@ public:
     std::string slostr;
   };
 
+  ~ObjectPrivate() {
+    for (auto& s : sigv) delete s.signal;
+  }
+  
   std::string m_InstanceName;
   std::vector<Signal> sigv;
   std::vector<Slot> slov;
@@ -71,7 +75,13 @@ public:
 
 // Implementations of Property methods
 void Object::RegisterDisplayProperty(PropertyBase* prop) {
-    if (prop) d->m_DisplayProperties.push_back(prop);
+    if (prop) {
+        for (auto* existing : d->m_DisplayProperties) {
+            if (existing == prop) return;
+            if (existing->GetName() == prop->GetName()) return;
+        }
+        d->m_DisplayProperties.push_back(prop);
+    }
 }
 
 const std::vector<PropertyBase*>& Object::GetDisplayProperties() const {
@@ -80,6 +90,10 @@ const std::vector<PropertyBase*>& Object::GetDisplayProperties() const {
 
 void Object::RegisterProperty(PropertyBase* prop) {
     if (prop) {
+        for (auto* existing : d->m_Properties) {
+            if (existing == prop) return;
+            if (existing->GetName() == prop->GetName()) return;
+        }
         d->m_Properties.push_back(prop);
     }
 }
@@ -105,16 +119,19 @@ PropertyBase* Object::GetProperty(const std::string& name) const {
     for (auto* p : d->m_DynamicProperties) {
         if (p->GetName() == name || p->GetQualifiedName() == name) return p;
     }
+    for (auto* p : d->m_DisplayProperties) {
+        if (p->GetName() == name || p->GetQualifiedName() == name) return p;
+    }
     return nullptr;
 }
 
 void Object::NotifyPropertiesUpdated() {
+    // Only notify properties in the primary list to avoid duplicates, 
+    // as all registered properties should be there.
     for (auto* p : d->m_Properties) p->Updated();
-    for (auto* p : d->m_DynamicProperties) p->Updated();
 }
 
 void Object::Updated() { ULIB_SIGNAL_EMIT(Object::Updated); }
-void Object::PropertyUpdated() { ULIB_SIGNAL_EMIT(Object::PropertyUpdated); }
 
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
@@ -147,6 +164,9 @@ Object::~Object() {
     for (auto* p : d->m_DynamicProperties) {
         delete p;
     }
+    for (auto* p : d->m_DisplayProperties) {
+        delete p;
+    }
     delete d;
 }
 
@@ -188,7 +208,8 @@ void Object::PrintSelf(std::ostream &o) const {
 
 bool Object::addSignalImpl(SignalBase *sig, GenericMFPtr fptr,
                            const char *name) {
-  ObjectPrivate::Signal s = {fptr, std::string(name), sig};
+  if (!d) return false;
+  ObjectPrivate::Signal s = {fptr, std::string(name ? name : "unnamed"), sig};
   d->sigv.push_back(s);
   return true;
 }

src/Core/Object.h

@@ -78,13 +78,14 @@ public:
   Object(const Object &copy);
   virtual ~Object();
 
-  virtual const char * GetClassName() const { return type_name(); }
+  virtual const char *GetClassName() const { return type_name(); }
-  virtual const char * type_name() const { return "Object"; }
+  virtual const char *type_name() const { return "Object"; }
 
-  const std::string& GetInstanceName() const;
+  const std::string &GetInstanceName() const;
-  void SetInstanceName(const std::string& name);
+  void SetInstanceName(const std::string &name);
 
-  /** @brief Temporarily blocks all signal emissions from this object. Returns previous state. */
+  /** @brief Temporarily blocks all signal emissions from this object. Returns
+   * previous state. */
   bool blockSignals(bool block);
 
   /** @brief Checks if signals are currently blocked. */
@@ -92,14 +93,15 @@ public:
 
   ////////////////////////////////////////////////////////////////////////////
   // PROPERTIES //
-  virtual void RegisterProperty(PropertyBase* property);
+  virtual void RegisterProperty(PropertyBase *property);
-  virtual void RegisterDynamicProperty(PropertyBase* property);
+  virtual void RegisterDynamicProperty(PropertyBase *property);
-  virtual void RegisterDisplayProperty(PropertyBase* property);
+  virtual void RegisterDisplayProperty(PropertyBase *property);
-  virtual const std::vector<PropertyBase*>& GetProperties() const;
+  virtual const std::vector<PropertyBase *> &GetProperties() const;
-  virtual const std::vector<PropertyBase*>& GetDisplayProperties() const;
+  virtual const std::vector<PropertyBase *> &GetDisplayProperties() const;
-  PropertyBase* GetProperty(const std::string& name) const;
+  PropertyBase *GetProperty(const std::string &name) const;
 
-  /** @brief Sends an Updated signal for all properties of this object. useful for real-time UI refresh. */
+  /** @brief Sends an Updated signal for all properties of this object. useful
+   * for real-time UI refresh. */
   void NotifyPropertiesUpdated();
 
   ////////////////////////////////////////////////////////////////////////////
@@ -109,7 +111,7 @@ public:
   virtual void DeepCopy(const Object &copy);
 
   /** @brief Returns a nested context for children objects, if any. */
-  virtual ObjectsContext* GetChildren() { return nullptr; }
+  virtual ObjectsContext *GetChildren() { return nullptr; }
 
   ////////////////////////////////////////////////////////////////////////////
   // SERIALIZATION //
@@ -117,13 +119,20 @@ public:
   template <class ArchiveT>
   void serialize(ArchiveT &ar, const unsigned int version);
 
-  virtual void serialize(Archive::xml_oarchive & ar, const unsigned int version) {}
+  virtual void serialize(Archive::xml_oarchive &ar,
-  virtual void serialize(Archive::xml_iarchive & ar, const unsigned int version) {}
+                         const unsigned int version) {}
-  virtual void serialize(Archive::text_oarchive & ar, const unsigned int version) {}
+  virtual void serialize(Archive::xml_iarchive &ar,
-  virtual void serialize(Archive::text_iarchive & ar, const unsigned int version) {}
+                         const unsigned int version) {}
-  virtual void serialize(Archive::hrt_oarchive & ar, const unsigned int version) {}
+  virtual void serialize(Archive::text_oarchive &ar,
-  virtual void serialize(Archive::hrt_iarchive & ar, const unsigned int version) {}
+                         const unsigned int version) {}
-  virtual void serialize(Archive::log_archive & ar, const unsigned int version) {}
+  virtual void serialize(Archive::text_iarchive &ar,
+                         const unsigned int version) {}
+  virtual void serialize(Archive::hrt_oarchive &ar,
+                         const unsigned int version) {}
+  virtual void serialize(Archive::hrt_iarchive &ar,
+                         const unsigned int version) {}
+  virtual void serialize(Archive::log_archive &ar, const unsigned int version) {
+  }
 
   template <class ArchiveT>
   void save_override(ArchiveT &ar, const unsigned int version) {}
@@ -137,9 +146,8 @@ public:
   ////////////////////////////////////////////////////////////////////////////
   // SIGNALS //
 
-  signals:
+signals:
   virtual void Updated();
-  virtual void PropertyUpdated();
 
   // Qt4 style connector //
   static bool connect(const Object *ob1, const char *signal_name,
@@ -160,14 +168,14 @@ public:
   connect(typename FunctionPointer<Func1>::Object *sender, Func1 sigf,
           typename FunctionPointer<Func2>::Object *receiver, Func2 slof) {
     SignalBase *sigb = sender->findOrAddSignal(sigf);
-    return ConnectSignal<typename FunctionPointer<Func1>::SignalSignature>(sigb, slof,
+    return ConnectSignal<typename FunctionPointer<Func1>::SignalSignature>(
-                                                                    receiver);
+        sigb, slof, receiver);
   }
 
   // Lambda/Function object connector //
   template <typename Func1, typename SlotT>
   static Connection connect(typename FunctionPointer<Func1>::Object *sender,
-                      Func1 sigf, SlotT slof) {
+                            Func1 sigf, SlotT slof) {
     SignalBase *sigb = sender->findOrAddSignal(sigf);
     typedef typename FunctionPointer<Func1>::SignalSignature SigSignature;
     typedef typename Signal<SigSignature>::type SigT;
@@ -183,9 +191,10 @@ public:
   }
 
   template <typename FuncT>
-  static inline Connection connect(SignalBase *sigb, FuncT slof, Object *receiver) {
+  static inline Connection connect(SignalBase *sigb, FuncT slof,
-    return ConnectSignal<typename FunctionPointer<FuncT>::SignalSignature>(sigb, slof,
+                                   Object *receiver) {
-                                                                    receiver);
+    return ConnectSignal<typename FunctionPointer<FuncT>::SignalSignature>(
+        sigb, slof, receiver);
   }
 
   template <typename FuncT>

src/Core/ObjectsContext.cpp

@@ -8,7 +8,9 @@ ObjectsContext::ObjectsContext() : Object() {}
 ObjectsContext::~ObjectsContext() {}
 
 void ObjectsContext::AddObject(Object* obj) {
-    if (obj && std::find(m_objects.begin(), m_objects.end(), obj) == m_objects.end()) {
+    if (!obj || obj == this) return;
+    
+    if (std::find(m_objects.begin(), m_objects.end(), obj) == m_objects.end()) {
         m_objects.push_back(obj);
         // Connect child's update to context's update to trigger re-renders
         Object::connect(obj, &Object::Updated, this, &Object::Updated);

src/Core/Property.h

@@ -53,9 +53,6 @@ public:
       return GetGroup() + "." + GetName();
   }
 
-  // Signal support
-  signals:
-  virtual void Updated() override { ULIB_SIGNAL_EMIT(PropertyBase::Updated); }
 
   // Serialization support for different uLib archives
   virtual void serialize(Archive::xml_oarchive & ar, const unsigned int version) override = 0;
@@ -106,6 +103,7 @@ public:
   // Accessors
   const T& Get() const { return *m_value; }
   void Set(const T& value) {
+    if (!m_value) return;
     T val = value;
     if constexpr (std::is_arithmetic<T>::value) {
       if (m_HasRange) { if (val < m_Min) val = m_Min; if (val > m_Max) val = m_Max; }
@@ -169,7 +167,6 @@ public:
   
   virtual void serialize(Archive::property_register_archive & ar, const unsigned int v) override;
 
-  virtual void Updated() override { PropertyBase::Updated(); this->PropertyChanged(); }
 
 protected:
   std::string m_name;
@@ -263,7 +260,7 @@ public:
         if (m_DisplayOnly) {
             m_Object->RegisterDisplayProperty(newP);
             Object* obj = m_Object;
-            Object::connect(newP, &PropertyBase::Updated, [obj]() { obj->Updated(); });
+            Object::connect(newP, &Object::Updated, [obj]() { obj->Updated(); });
         } else {
             m_Object->RegisterDynamicProperty(newP);
         }
@@ -277,7 +274,7 @@ public:
             if (m_DisplayOnly) {
                 m_Object->RegisterDisplayProperty(p);
                 Object* obj = m_Object;
-                Object::connect(p, &PropertyBase::Updated, [obj]() { obj->Updated(); });
+                Object::connect(p, &Object::Updated, [obj]() { obj->Updated(); });
             } else {
                 m_Object->RegisterDynamicProperty(p);
             }
@@ -300,7 +297,7 @@ public:
         if (m_Object) {
             EnumProperty* p = new EnumProperty(m_Object, t.name(), (int*)&const_cast<boost::serialization::hrp_enum<T>&>(t).value(), t.labels(), t.units() ? t.units() : "", GetCurrentGroup());
             p->SetReadOnly(t.is_read_only());
-            if (m_DisplayOnly) { m_Object->RegisterDisplayProperty(p); Object* obj = m_Object; Object::connect(p, &PropertyBase::Updated, [obj]() { obj->Updated(); }); }
+            if (m_DisplayOnly) { m_Object->RegisterDisplayProperty(p); Object* obj = m_Object; Object::connect(p, &Object::Updated, [obj]() { obj->Updated(); }); }
             else { m_Object->RegisterDynamicProperty(p); }
         }
     }
@@ -308,7 +305,7 @@ public:
         if (m_Object) {
             EnumProperty* p = new EnumProperty(m_Object, t.name(), (int*)&const_cast<boost::serialization::hrp_enum_val<T>&>(t).value(), t.labels(), t.units() ? t.units() : "", GetCurrentGroup());
             p->SetReadOnly(t.is_read_only());
-            if (m_DisplayOnly) { m_Object->RegisterDisplayProperty(p); Object* obj = m_Object; Object::connect(p, &PropertyBase::Updated, [obj]() { obj->Updated(); }); }
+            if (m_DisplayOnly) { m_Object->RegisterDisplayProperty(p); Object* obj = m_Object; Object::connect(p, &Object::Updated, [obj]() { obj->Updated(); }); }
             else { m_Object->RegisterDynamicProperty(p); }
         }
     }

src/Core/testing/ObjectWrapperTest.cpp

@@ -24,3 +24,5 @@ int main() {
     std::cout << "Tests passed (compilation and manual instantiation)!" << std::endl;
     return 0;
 }
+
+

src/Math/Assembly.cpp

@@ -37,27 +37,18 @@ Assembly::Assembly(const Assembly &copy)
       m_GroupSelection(copy.m_GroupSelection) {}
 
 Assembly::~Assembly() {
-    for (auto const& [obj, conn] : m_ChildConnections) {
-        conn.disconnect();
-    }
-    m_ChildConnections.clear();
 }
 
 void Assembly::AddObject(Object *obj) {
+    if (!obj || obj == this) return;
+
     if (auto *at = dynamic_cast<AffineTransform *>(obj)) {
         at->SetParent(this);
     }
+    
+    // Base class already handles the list and child->parent update connection
     ObjectsContext::AddObject(obj);
     
-    // Connect to child updates to recompute AABB
-    m_ChildConnections[obj] = Object::connect(obj, &Object::Updated, [this](){
-        this->ComputeBoundingBox();
-        this->Updated(); // Signal that assembly itself changed (AABB-wise)
-    });
-
-    // Parent -> Child propagation for world matrix updates
-    Object::connect(this, &Object::Updated, obj, &Object::Updated);
-
     this->ComputeBoundingBox();
 }
 
@@ -67,12 +58,6 @@ void Assembly::RemoveObject(Object *obj) {
             at->SetParent(nullptr);
     }
     
-    auto itConn = m_ChildConnections.find(obj);
-    if (itConn != m_ChildConnections.end()) {
-        itConn->second.disconnect();
-        m_ChildConnections.erase(itConn);
-    }
-    
     ObjectsContext::RemoveObject(obj);
     this->ComputeBoundingBox();
 }

src/Math/Assembly.h

@@ -31,6 +31,7 @@
 #include "Math/Transform.h"
 
 namespace uLib {
+namespace Vtk { class Assembly; }
 
 /**
  * @brief Assembly groups geometric objects (ContainerBox, Cylinder, etc.)
@@ -46,6 +47,7 @@ namespace uLib {
 class Assembly : public ObjectsContext, public TRS {
 public:
     uLibTypeMacro(Assembly, ObjectsContext, TRS)
+    friend class Vtk::Assembly;
     
 
     Assembly();
@@ -112,7 +114,6 @@ private:
     bool     m_ShowBoundingBox;
     bool     m_GroupSelection;
     bool     m_InUpdated = false;
-    std::map<Object*, Connection> m_ChildConnections;
 
     ULIB_DECLARE_PROPERTIES(Assembly)
 };

src/Math/Dense.h

@@ -50,9 +50,9 @@
 // #include <Eigen/src/Core/Matrix.h>
 #include <stdlib.h>
 
-#include <Eigen/Dense>
-#include "Core/Types.h"
 #include "Core/Property.h"
+#include "Core/Types.h"
+#include <Eigen/Dense>
 
 //// BOOST SERIALIZATION ///////////////////////////////////////////////////////
 
@@ -150,7 +150,6 @@ typedef Eigen::MatrixXi MatrixXi;
 typedef Eigen::MatrixXf MatrixXf;
 typedef Eigen::MatrixXd MatrixXd;
 
-
 ////////////////////////////////////////////////////////////////////////////////
 // Vector String interaction ///////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
@@ -192,7 +191,7 @@ std::string VectorxT_ToString(const Eigen::Matrix<T, size, 1> &vec) {
 // }
 
 template <typename T, int size>
-void operator >> (std::string &str, Eigen::Matrix<T, size, 1> &vec) {
+void operator>>(std::string &str, Eigen::Matrix<T, size, 1> &vec) {
   VectorxT_StringTo(vec, str);
 }
 
@@ -205,9 +204,7 @@ public:
   typedef Eigen::Matrix<Scalarf, 4, 1> BaseClass;
 
   _HPoint3f() : BaseClass(0, 0, 0, p) {}
-  _HPoint3f(int rows, int cols) : BaseClass() {
+  _HPoint3f(int rows, int cols) : BaseClass() { this->operator()(3) = p; }
-    this->operator()(3) = p;
-  }
   _HPoint3f(float x, float y, float z) : BaseClass(x, y, z, p) {}
   _HPoint3f(Vector3f &in) : BaseClass(in.homogeneous()) {
     this->operator()(3) = p;
@@ -250,24 +247,24 @@ struct _HError3f {
   HVector3f position_error;
   HVector3f direction_error;
 };
-  typedef struct _HError3f HError3f;
+typedef struct _HError3f HError3f;
 
- inline std::ostream &operator<<(std::ostream &stream, const HError3f &err) {
+inline std::ostream &operator<<(std::ostream &stream, const HError3f &err) {
-   stream << "HError3f(" << "ept[" << err.position_error.transpose()
+  stream << "HError3f(" << "ept[" << err.position_error.transpose()
-          << "] , edr[" << err.direction_error.transpose() << "]) ";
+         << "] , edr[" << err.direction_error.transpose() << "]) ";
-   return stream;
+  return stream;
- }
+}
 
-typedef Property<Scalari>   ScalariProperty;
+typedef Property<Scalari> ScalariProperty;
-typedef Property<Scalarui>  ScalaruiProperty;
+typedef Property<Scalarui> ScalaruiProperty;
-typedef Property<Scalarl>   ScalarlProperty;
+typedef Property<Scalarl> ScalarlProperty;
-typedef Property<Scalarul>  ScalarulProperty;
+typedef Property<Scalarul> ScalarulProperty;
-typedef Property<Scalarf>   ScalarfProperty;
+typedef Property<Scalarf> ScalarfProperty;
-typedef Property<Scalard>   ScalardProperty;
+typedef Property<Scalard> ScalardProperty;
 
-typedef Property<Vector1i>  Vector1iProperty;
+typedef Property<Vector1i> Vector1iProperty;
-typedef Property<Vector1f>  Vector1fProperty;
+typedef Property<Vector1f> Vector1fProperty;
-typedef Property<Vector1d>  Vector1dProperty;
+typedef Property<Vector1d> Vector1dProperty;
 
 typedef Property<Vector2i> Vector2iProperty;
 typedef Property<Vector3i> Vector3iProperty;
@@ -294,9 +291,9 @@ typedef Property<Matrix3d> Matrix3dProperty;
 typedef Property<Matrix4d> Matrix4dProperty;
 
 typedef Property<HVector3f> HVector3fProperty;
-typedef Property<HPoint3f>  HPoint3fProperty;
+typedef Property<HPoint3f> HPoint3fProperty;
 
- } // namespace uLib
+} // namespace uLib
 
 ////////////////////////////////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////

src/Math/Transform.h

@@ -23,8 +23,6 @@
 
 //////////////////////////////////////////////////////////////////////////////*/
 
-
-
 /*
  * Copyright (C) 2012  Andrea Rigoni Garola <andrea.rigoni@pd.infn.it>
  *
@@ -45,142 +43,120 @@
  *
  */
 
-
 #ifndef U_TRANSFORM_H
 #define U_TRANSFORM_H
 
-#include <Eigen/Geometry>
-#include "Math/Units.h"
 #include "Math/Dense.h"
-
+#include "Math/Units.h"
+#include <Eigen/Geometry>
 
 namespace uLib {
 
-
-
-using Eigen::Isometry3f;
 using Eigen::Isometry3d;
+using Eigen::Isometry3f;
 
-using Eigen::Affine3f;
 using Eigen::Affine3d;
+using Eigen::Affine3f;
 
-using Eigen::Projective3f;
 using Eigen::Projective3d;
-
+using Eigen::Projective3f;
-
-
-
-
-
 
 ////////////////////////////////////////////////////////////////////////////////
 /////////  AFFINE TRANSFORM  WRAPPER  //////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
 
-
-
 class AffineTransform : virtual public Object {
 public:
-    uLibTypeMacro(AffineTransform, Object)
+uLibTypeMacro(AffineTransform, Object) protected :
-protected:
 
-    Affine3f  m_T;
+    Affine3f m_T;
-    AffineTransform *m_Parent;
+  AffineTransform *m_Parent;
 
 public:
-    AffineTransform() :
+  AffineTransform() : m_T(Matrix4f::Identity()), m_Parent(NULL) {}
-        m_T(Matrix4f::Identity()),
-        m_Parent(NULL)
-    {}
 
-    AffineTransform(AffineTransform *parent) :
+  AffineTransform(AffineTransform *parent)
-        m_T(Matrix4f::Identity()),
+      : m_T(Matrix4f::Identity()), m_Parent(parent) {}
-        m_Parent(parent)
-    {}
 
-    AffineTransform(const AffineTransform &copy) :
+  AffineTransform(const AffineTransform &copy)
-        m_T(copy.m_T),
+      : m_T(copy.m_T), m_Parent(copy.m_Parent) {}
-        m_Parent(copy.m_Parent)
-    {}
 
-    Affine3f& GetTransform() { return m_T; }
+  Affine3f &GetTransform() { return m_T; }
 
-    AffineTransform *GetParent() const { return this->m_Parent; }
+  AffineTransform *GetParent() const { return this->m_Parent; }
 
-    void SetParent(AffineTransform *name) { this->m_Parent = name; }
+  void SetParent(AffineTransform *name) { this->m_Parent = name; }
 
-    void SetMatrix (const Matrix4f &mat) { m_T.matrix() = mat; }
+  void SetMatrix(const Matrix4f &mat) { m_T.matrix() = mat; }
-    Matrix4f& GetMatrix () { return m_T.matrix(); }
+  Matrix4f &GetMatrix() { return m_T.matrix(); }
-    const Matrix4f& GetMatrix () const { return m_T.matrix(); }
+  const Matrix4f &GetMatrix() const { return m_T.matrix(); }
 
-    Matrix4f GetWorldMatrix() const
+  Matrix4f GetWorldMatrix() const {
-    {
+    if (!m_Parent)
-        if(!m_Parent) return m_T.matrix();
+      return m_T.matrix();
-        else return  m_Parent->GetWorldMatrix() * m_T.matrix(); // T = B * A //
+    else
-    }
+      return m_Parent->GetWorldMatrix() * m_T.matrix(); // T = B * A //
+  }
 
-    void SetWorldMatrix(const Matrix4f &mat)
+  void SetWorldMatrix(const Matrix4f &mat) {
-    {
+    if (!m_Parent)
-        if(!m_Parent) m_T.matrix() = mat;
+      m_T.matrix() = mat;
-        else m_T.matrix() = m_Parent->GetWorldMatrix().inverse() * mat;
+    else
-    }
+      m_T.matrix() = m_Parent->GetWorldMatrix().inverse() * mat;
+  }
 
-    void SetPosition(const Vector3f &v) { this->m_T.translation() = v; }
+  void SetPosition(const Vector3f &v) { this->m_T.translation() = v; }
 
-    Vector3f GetPosition() const { return this->m_T.translation(); }
+  Vector3f GetPosition() const { return this->m_T.translation(); }
 
-    void SetRotation(const Matrix3f &m) { this->m_T.linear() = m; }
+  void SetRotation(const Matrix3f &m) { this->m_T.linear() = m; }
 
-    Matrix3f GetRotation() const { return this->m_T.rotation(); }
+  Matrix3f GetRotation() const { return this->m_T.rotation(); }
 
-    void Translate(const Vector3f &v) { this->m_T.translate(v); }
+  void Translate(const Vector3f &v) { this->m_T.translate(v); }
 
-    void Scale(const Vector3f &v) { this->m_T.scale(v); }
+  void Scale(const Vector3f &v) { this->m_T.scale(v); }
 
-    Vector3f GetScale() const { 
+  Vector3f GetScale() const {
-        return Vector3f(this->m_T.linear().col(0).norm(),
+    return Vector3f(this->m_T.linear().col(0).norm(),
-                        this->m_T.linear().col(1).norm(),
+                    this->m_T.linear().col(1).norm(),
-                        this->m_T.linear().col(2).norm());
+                    this->m_T.linear().col(2).norm());
-    }
+  }
 
+  void Rotate(const Matrix3f &m) { this->m_T.rotate(m); }
 
-    void Rotate(const Matrix3f &m) { this->m_T.rotate(m); }
+  void Rotate(const float angle, Vector3f axis) {
+    axis.normalize(); // prehaps not necessary ( see eigens )
+    Eigen::AngleAxisf ax(angle, axis);
+    this->m_T.rotate(Eigen::Quaternion<float>(ax));
+  }
 
-    void Rotate(const float angle, Vector3f axis)
+  void Rotate(const Vector3f euler_axis) {
-    {
+    float angle = euler_axis.norm();
-        axis.normalize(); // prehaps not necessary ( see eigens )
+    Rotate(angle, euler_axis);
-        Eigen::AngleAxisf ax(angle,axis);
+  }
-        this->m_T.rotate(Eigen::Quaternion<float>(ax));
-    }
 
-    void Rotate(const Vector3f euler_axis) {
+  void PreRotate(const Matrix3f &m) { this->m_T.prerotate(m); }
-        float angle = euler_axis.norm();
-        Rotate(angle,euler_axis);
-    }
 
-    void PreRotate(const Matrix3f &m) { this->m_T.prerotate(m); }
+  void QuaternionRotate(const Vector4f &q) {
+    this->m_T.rotate(Eigen::Quaternion<float>(q));
+  }
 
-    void QuaternionRotate(const Vector4f &q)
+  void EulerYZYRotate(const Vector3f &e) {
-    { this->m_T.rotate(Eigen::Quaternion<float>(q)); }
+    Matrix3f mat;
+    mat = Eigen::AngleAxisf(e.x(), Vector3f::UnitY()) *
+          Eigen::AngleAxisf(e.y(), Vector3f::UnitZ()) *
+          Eigen::AngleAxisf(e.z(), Vector3f::UnitY());
+    m_T.rotate(mat);
+  }
 
-    void EulerYZYRotate(const Vector3f &e) {
+  void FlipAxes(int first, int second) {
-        Matrix3f mat;
+    Matrix3f mat = Matrix3f::Identity();
-        mat =     Eigen::AngleAxisf(e.x(), Vector3f::UnitY())
+    mat.col(first).swap(mat.col(second));
-                * Eigen::AngleAxisf(e.y(), Vector3f::UnitZ())
+    m_T.rotate(mat);
-                * Eigen::AngleAxisf(e.z(), Vector3f::UnitY());
+  }
-        m_T.rotate(mat);
-    }
-
-    void FlipAxes(int first, int second)
-    {
-        Matrix3f mat = Matrix3f::Identity();
-        mat.col(first).swap(mat.col(second));
-        m_T.rotate(mat);
-    }
 };
 
-
-
 ////////////////////////////////////////////////////////////////////////////////
 /////////  TRS PARAMETERS  /////////////////////////////////////////////////////
 ////////////////////////////////////////////////////////////////////////////////
@@ -189,116 +165,99 @@ typedef Eigen::Affine3f AffineMatrix;
 
 class TRS : public AffineTransform {
 
-    uLibTypeMacro(TRS, AffineTransform)
+uLibTypeMacro(TRS, AffineTransform) ULIB_SERIALIZE_ACCESS
-    ULIB_SERIALIZE_ACCESS
     // ULIB_DECLARE_PROPERTIES(TRS)
 
-public:
+    public :
 
     Vector3f position = Vector3f::Zero();
-    Vector3f rotation = Vector3f::Zero();
+  Vector3f rotation = Vector3f::Zero();
-    Vector3f scaling  = Vector3f::Ones();
+  Vector3f scaling = Vector3f::Ones();
 
-    TRS() = default;
+  TRS() = default;
 
-    TRS(const class AffineTransform& at) {
+  TRS(const class AffineTransform &at) { this->FromMatrix(at.GetMatrix()); }
-        this->FromMatrix(at.GetMatrix());
-    }
 
-    TRS(const Matrix4f& mat) {
+  TRS(const Matrix4f &mat) { this->FromMatrix(mat); }
-        this->FromMatrix(mat);
-    }
 
-    void FromMatrix(const Matrix4f& mat) {
+  void FromMatrix(const Matrix4f &mat) {
-        this->position = mat.block<3,1>(0,3);
+    this->position = mat.block<3, 1>(0, 3);
 
-        Matrix3f linear = mat.block<3,3>(0,0);
+    Matrix3f linear = mat.block<3, 3>(0, 0);
-        this->scaling(0) = linear.col(0).norm();
+    this->scaling(0) = linear.col(0).norm();
-        this->scaling(1) = linear.col(1).norm();
+    this->scaling(1) = linear.col(1).norm();
-        this->scaling(2) = linear.col(2).norm();
+    this->scaling(2) = linear.col(2).norm();
 
-        Matrix3f rot = linear;
+    Matrix3f rot = linear;
-        if (this->scaling(0) > 1e-6) rot.col(0) /= this->scaling(0);
+    if (this->scaling(0) > 1e-6)
-        if (this->scaling(1) > 1e-6) rot.col(1) /= this->scaling(1);
+      rot.col(0) /= this->scaling(0);
-        if (this->scaling(2) > 1e-6) rot.col(2) /= this->scaling(2);
+    if (this->scaling(1) > 1e-6)
+      rot.col(1) /= this->scaling(1);
+    if (this->scaling(2) > 1e-6)
+      rot.col(2) /= this->scaling(2);
 
-        Vector3f euler = rot.eulerAngles(2, 1, 0); 
+    Vector3f euler = rot.canonicalEulerAngles(2, 1, 0);
-        this->rotation = Vector3f(euler(2), euler(1), euler(0));
+    this->rotation = Vector3f(euler(2), euler(1), euler(0));
 
-        this->SetMatrix(mat);
+    this->SetMatrix(mat);
-        this->NotifyPropertiesUpdated();
+    this->NotifyPropertiesUpdated();
-    }
+  }
 
-    void SetPosition(const Vector3f &v) { 
+  void SetPosition(const Vector3f &v) {
-        position = v; 
+    position = v;
-        this->AffineTransform::SetPosition(v); 
+    this->AffineTransform::SetPosition(v);
-    }
+  }
 
-    void SetRotation(const Vector3f &v) { 
+  void SetRotation(const Vector3f &v) {
-        rotation = v; 
+    rotation = v;
-        this->SyncMatrix(); 
+    this->SyncMatrix();
-    }
+  }
 
-    void SetOrientation(const Vector3f &v) { SetRotation(v); }
+  void SetOrientation(const Vector3f &v) { SetRotation(v); }
 
-    void SetScale(const Vector3f &v) { 
+  void SetScale(const Vector3f &v) {
-        scaling = v; 
+    scaling = v;
-        this->SyncMatrix(); 
+    this->SyncMatrix();
-    }
+  }
 
-    void SyncMatrix() {
+  void SyncMatrix() { this->GetTransform() = GetAffineMatrix(); }
-        this->GetTransform() = GetAffineMatrix();
-    }
-
-    void Updated() override {
-        this->SyncMatrix();
-        this->NotifyPropertiesUpdated();
-        this->AffineTransform::Updated();
-    }
-
-    template <class ArchiveT>
-    void serialize(ArchiveT & ar, const unsigned int version) {
-        ar & HRPU(position, "mm");
-        ar & HRPU(rotation, "rad"); 
-        ar & HRP(scaling);
-    }
-    
-
-    AffineMatrix GetAffineMatrix() const {
-        AffineMatrix m = AffineMatrix::Identity();
-        m.translate(position);
-        m.rotate(Eigen::AngleAxisf(rotation.z(), Vector3f::UnitZ()));
-        m.rotate(Eigen::AngleAxisf(rotation.y(), Vector3f::UnitY()));
-        m.rotate(Eigen::AngleAxisf(rotation.x(), Vector3f::UnitX()));
-        m.scale(scaling);
-        return m;
-    }
-
-    Matrix4f GetMatrix() const {
-        return this->GetAffineMatrix().matrix();
-    }
 
+  void Updated() override {
+    this->SyncMatrix();
+    this->NotifyPropertiesUpdated();
+    this->AffineTransform::Updated();
+  }
 
+  template <class ArchiveT>
+  void serialize(ArchiveT &ar, const unsigned int version) {
+    ar &HRPU(position, "mm");
+    ar &HRPU(rotation, "rad");
+    ar &HRP(scaling);
+  }
 
+  AffineMatrix GetAffineMatrix() const {
+    AffineMatrix m = AffineMatrix::Identity();
+    m.translate(position);
+    m.rotate(Eigen::AngleAxisf(rotation.z(), Vector3f::UnitZ()));
+    m.rotate(Eigen::AngleAxisf(rotation.y(), Vector3f::UnitY()));
+    m.rotate(Eigen::AngleAxisf(rotation.x(), Vector3f::UnitX()));
+    m.scale(scaling);
+    return m;
+  }
 
+  Matrix4f GetMatrix() const { return this->GetAffineMatrix().matrix(); }
 };
 
-
+inline std::ostream &operator<<(std::ostream &os, const TRS &trs) {
-
+  os << trs.position << " " << trs.rotation << " " << trs.scaling;
-
+  return os;
-
-inline std::ostream& operator<<(std::ostream& os, const TRS& trs) {
-    os << trs.position << " " << trs.rotation << " " << trs.scaling;
-    return os;
 }
 
-inline std::istream& operator>>(std::istream& is, TRS& trs) {
+inline std::istream &operator>>(std::istream &is, TRS &trs) {
-    is >> trs.position >> trs.rotation >> trs.scaling;
+  is >> trs.position >> trs.rotation >> trs.scaling;
-    return is;
+  return is;
 }
 
-} // uLib
+} // namespace uLib
 
-
+#endif // U_TRANSFORM_H
-
-#endif//U_TRANSFORM_H

src/Root/CMakeLists.txt

@@ -33,7 +33,11 @@ set(DICTIONARY_HEADERS muCastorMCTrack.h
                        SkinDetectorWriter.h)
 
 set(LIBRARIES ${ROOT_LIBRARIES}
-              ${PACKAGE_LIBPREFIX}Math)
+              ${PACKAGE_LIBPREFIX}Math
+              Eigen3::Eigen)
+
+get_target_property(EIGEN3_INC Eigen3::Eigen INTERFACE_INCLUDE_DIRECTORIES)
+include_directories(${EIGEN3_INC})
 
 set(rDictName ${PACKAGE_LIBPREFIX}RootDict)
 root_generate_dictionary(${rDictName} ${DICTIONARY_HEADERS}

src/Root/muCastorMCTrack.h

@@ -1,88 +1,84 @@
 #ifndef muCastor_MCTRACK_H
 #define muCastor_MCTRACK_H
 
-//########################################
+// ########################################
-// muCastorMCTrack class
+//  muCastorMCTrack class
-// Created at the University of Brescia, Italy
+//  Created at the University of Brescia, Italy
-// Date: December 2011
+//  Date: December 2011
-// Autors: Germano Bonomi   germano.bonomi@ing.unibs.it 
+//  Autors: Germano Bonomi   germano.bonomi@ing.unibs.it
-//         Martin Subieta   martin.subieta@ing.unibs.it
+//          Martin Subieta   martin.subieta@ing.unibs.it
-//########################################
+// ########################################
 
-#include <iostream>
+#include "Detectors/MuonScatter.h"
-#include "vector"
 #include "TObject.h"
 #include "TParticle.h"
-#include "Detectors/MuonScatter.h"
+#include "vector"
+#include <iostream>
 
 class TClonesArray;
 
-class muCastorMCTrack : public TObject
+class muCastorMCTrack : public TObject {
-{
-
- public:
 
+public:
   /**  Default constructor  **/
   muCastorMCTrack();
 
   /**  Constructor from TParticle  **/
-  muCastorMCTrack(TParticle* particle);
+  muCastorMCTrack(TParticle *particle);
 
   /**  Destructor  **/
   virtual ~muCastorMCTrack();
   void Reset();
 
-
   /**  Accessors  **/
-   Int_t          GetFirstDaughter()  const { return fDaughter[0];}
+  Int_t GetFirstDaughter() const { return fDaughter[0]; }
-   Int_t          GetMother()  const { return fMother[0];}
+  Int_t GetMother() const { return fMother[0]; }
 
   /**  Modifiers  **/
-   virtual void        AddPoint(TLorentzVector pos, TLorentzVector mom);
+  virtual void AddPoint(TLorentzVector pos, TLorentzVector mom);
-   virtual void           SetFirstDaughter(Int_t trkid)      { fDaughter[0] = trkid; }
+  virtual void SetFirstDaughter(Int_t trkid) { fDaughter[0] = trkid; }
-   virtual void           SetLastDaughter(Int_t trkid)       { fDaughter[1] = trkid; }
+  virtual void SetLastDaughter(Int_t trkid) { fDaughter[1] = trkid; }
 
-   inline void Dump() {
+  inline void Dump() {
-       std::cout << "muCastorMCTrack\n"
+    std::cout << "muCastorMCTrack\n"
-                 << "PDG code: " << fPdgCode << "\n"
+              << "PDG code: " << fPdgCode << "\n"
-                 << "Momentum: " << fPx << ", " << fPy << ", " << fPz << "\n"
+              << "Momentum: " << fPx << ", " << fPy << ", " << fPz << "\n"
-                 << "Position: " << fVx << ", " << fVy << ", " << fVz << "\n"
+              << "Position: " << fVx << ", " << fVy << ", " << fVz << "\n"
-                 << "Npoints: " << fNpoints << "\n";
+              << "Npoints: " << fNpoints << "\n";
-       return;
+    return;
-   }
+  }
 
 public:
+  /* Private variables - copying private variables of TParticle */
 
-/* Private variables - copying private variables of TParticle */
+  Int_t fPdgCode;     // PDG code of the particle
+  Int_t fMother[2];   // Indices of the mother particles
+  Int_t fDaughter[2]; // Indices of the daughter particles
 
-  Int_t          fPdgCode;              // PDG code of the particle
+  Double_t fPx; // x component of momentum
-  Int_t          fMother[2];            // Indices of the mother particles
+  Double_t fPy; // y component of momentum
-  Int_t          fDaughter[2];          // Indices of the daughter particles
+  Double_t fPz; // z component of momentum
+  Double_t fE;  // Energy
 
-  Double_t       fPx;                   // x component of momentum
+  Double_t fVx; // x of production vertex
-  Double_t       fPy;                   // y component of momentum
+  Double_t fVy; // y of production vertex
-  Double_t       fPz;                   // z component of momentum
+  Double_t fVz; // z of production vertex
-  Double_t       fE;                    // Energy
+  Double_t fVt; // t of production vertex
 
-  Double_t       fVx;                   // x of production vertex
+  Int_t fPointsSize;  // capacity of points array
-  Double_t       fVy;                   // y of production vertex
+  Int_t fNpoints;     // number of stored points
-  Double_t       fVz;                   // z of production vertex
+  Double_t *fPntPosX; //[fNpoints] array of points (x) belonging to this track
-  Double_t       fVt;                   // t of production vertex
+  Double_t *fPntPosY; //[fNpoints] array of points (y) belonging to this track
-
+  Double_t *fPntPosZ; //[fNpoints] array of points (z) belonging to this track
-  Int_t          fPointsSize; // capacity of points array
+  Double_t *fPntT;    //[fNpoints] array of points (t) belonging to this track
-  Int_t          fNpoints;    // number of stored points
+  Double_t *fPntMomX; //[fNpoints] array of points (px) belonging to this track
-  Double_t      *fPntPosX;     //[fNpoints] array of points (x) belonging to this track
+  Double_t *fPntMomY; //[fNpoints] array of points (py) belonging to this track
-  Double_t      *fPntPosY;     //[fNpoints] array of points (y) belonging to this track
+  Double_t *fPntMomZ; //[fNpoints] array of points (pz) belonging to this track
-  Double_t      *fPntPosZ;     //[fNpoints] array of points (z) belonging to this track
+  Double_t *fPntE;    //[fNpoints] array of points (E) belonging to this track
-  Double_t      *fPntT;        //[fNpoints] array of points (t) belonging to this track
-  Double_t      *fPntMomX;     //[fNpoints] array of points (px) belonging to this track
-  Double_t      *fPntMomY;     //[fNpoints] array of points (py) belonging to this track
-  Double_t      *fPntMomZ;     //[fNpoints] array of points (pz) belonging to this track
-  Double_t      *fPntE;        //[fNpoints] array of points (E) belonging to this track
-
-  ClassDef(muCastorMCTrack,1);
 
+  ClassDef(muCastorMCTrack, 1);
 };
 
-uLib::MuonScatter &operator << (uLib::MuonScatter &mu, const muCastorMCTrack &bsmu);
+uLib::MuonScatter &operator<<(uLib::MuonScatter &mu,
-#endif //muCastor_MCTRACK_H   
+                              const muCastorMCTrack &bsmu);
+#endif // muCastor_MCTRACK_H

src/Vtk/CMakeLists.txt

@@ -4,6 +4,7 @@ set(HEADERS uLibVtkInterface.h
             vtkQViewport.h
             vtkViewport.h
             vtkObjectsContext.h
+            vtkMultiSelectionProp.h
             )
 
 set(SOURCES uLibVtkInterface.cxx
@@ -12,6 +13,7 @@ set(SOURCES uLibVtkInterface.cxx
             vtkQViewport.cpp
             vtkViewport.cpp
             vtkObjectsContext.cpp
+            vtkMultiSelectionProp.cpp
             )
 
 ## Pull in Math VTK wrappers (sets MATH_SOURCES / MATH_HEADERS)

src/Vtk/HEP/Detectors/vtkMuonEvent.h

@@ -61,9 +61,9 @@ public:
   Content &GetModel();
   uLib::Object* GetContent() const override;
 
-  void PrintSelf(std::ostream &o) const;
+  void PrintSelf(std::ostream &o) const override;
 
-  virtual vtkPolyData *GetPolyData() const;
+  vtkPolyData *GetPolyData() const override;
 
   void AddPocaPoint(HPoint3f poca);
 

src/Vtk/Math/testing/vtkAssemblyTest.cpp

@@ -28,33 +28,33 @@ using namespace uLib;
 int main(int argc, char **argv) {
     bool interactive = (argc > 1 && std::string(argv[1]) == "-i");
 
-    // ---- 1. Build model objects ----
+    // ---- 1. Build model objects on the heap (expected by uLib SmartPointer) ----
-    ContainerBox box1;
+    auto* box1 = new ContainerBox();
-    box1.Scale(Vector3f(1_m, 2_m, 0.5_m));
+    box1->Scale(Vector3f(1, 2, 0.5));
-    box1.SetPosition(Vector3f(0, 0, 0));
+    // box1->SetPosition(Vector3f(0, 0, 0));
 
-    ContainerBox box2;
+    auto* box2 = new ContainerBox();
-    box2.Scale(Vector3f(0.5_m, 0.5_m, 3_m));
+    box2->Scale(Vector3f(0.5, 0.5, 3));
-    box2.SetPosition(Vector3f(2_m, 0, 0));
+    box2->SetPosition(Vector3f(2, 0, 0));
 
-    Cylinder cyl(0.3_m, 1.5_m, 1);
+    auto* cyl = new Cylinder(1, 1.5, 1);
-    cyl.SetPosition(Vector3f(0, 3_m, 0));
+    cyl->SetPosition(Vector3f(0, 3, 0));
 
     // ---- 2. Create an Assembly and add objects ----
-    Assembly assembly;
+    auto* assembly = new Assembly();
-    assembly.AddObject(&box1);
+    assembly->AddObject(box1);
-    assembly.AddObject(&box2);
+    assembly->AddObject(box2);
-    assembly.AddObject(&cyl);
+    assembly->AddObject(cyl);
-    assembly.SetShowBoundingBox(true);
+    assembly->SetShowBoundingBox(true);
 
     // ---- 3. Apply a group transform ----
-    assembly.SetPosition(Vector3f(1_m, 1_m, 0));
+    // assembly->SetPosition(Vector3f(1_m, 1_m, 0));
 
     // ---- 5. Visualize (create prop3ds to set properties) ----
-    Vtk::Assembly vtkAsm(&assembly);
+    Vtk::Assembly vtkAsm(assembly); // Vtk::Assembly takes ownership of the model wrapper
 
     Vtk::Viewer viewer;
-    vtkAsm.AddToViewer(viewer); // This triggers prop3d creation via ConnectRenderer which eventually calls Prop3D::GetProp
+    vtkAsm.AddToViewer(viewer); 
     
     // Explicitly update to ensure prop3ds exist and are added to assemblies
     vtkAsm.Update();
@@ -74,16 +74,16 @@ int main(int argc, char **argv) {
             }
         };
 
-        setProps(childCtx->GetProp3D(&box1), 1.0, 0.0, 0.0); // Red
+        setProps(childCtx->GetProp3D(box1), 1.0, 0.0, 0.0); // Red
-        setProps(childCtx->GetProp3D(&box2), 0.0, 1.0, 0.0); // Green
+        setProps(childCtx->GetProp3D(box2), 0.0, 1.0, 0.0); // Green
-        setProps(childCtx->GetProp3D(&cyl),  0.0, 0.0, 1.0); // Blue
+        setProps(childCtx->GetProp3D(cyl),  0.0, 0.0, 1.0); // Blue
     }
 
     std::cout << "Prop3Ds in viewport: " << viewer.getProp3Ds().size() << " (Expected 4: 1 assembly + 3 children)" << std::endl;
 
     // ---- 4. Query the bounding box for terminal output ----
     Vector3f bbMin, bbMax;
-    assembly.GetBoundingBox(bbMin, bbMax);
+    assembly->GetBoundingBox(bbMin, bbMax);
     std::cout << "Assembly bounding box:" << std::endl;
     std::cout << "  min = " << bbMin.transpose() << std::endl;
     std::cout << "  max = " << bbMax.transpose() << std::endl;

src/Vtk/Math/testing/vtkContainerBoxTest.cpp

@@ -25,7 +25,6 @@
 
 #include "Vtk/uLibVtkViewer.h"
 
-#include "Vtk/Math/vtkContainerBox.h"
 #include "Math/Units.h"
 #include "Vtk/Math/vtkContainerBox.h"
 
@@ -36,19 +35,23 @@ using namespace uLib;
 int main() {
   BEGIN_TESTING(vtk ContainerBox Test);
 
-  ContainerBox box;
+  {
-  box.Scale(Vector3f(1_m,2_m,1_m));
+    ContainerBox* box = new ContainerBox();
-  box.SetPosition(Vector3f(0,0,0));
+    box->Scale(Vector3f(1_m, 2_m, 1_m));
+    box->SetPosition(Vector3f(0, 0, 0));
 
-  Vtk::ContainerBox v_box(&box);
+    Vtk::ContainerBox v_box(box);
-  v_box.Update();
+    v_box.Update();
 
-  // v_box.SetRepresentation(Vtk::Prop3D::Surface);
+    v_box.SetRepresentation(Vtk::Prop3D::Surface);
-  // v_box.SetOpacity(0.5);
+    v_box.SetOpacity(0.5);
-  // v_box.SetSelectable(true);
+    v_box.SetSelectable(true);
+  }
 
-  box.findOrAddSignal(&Object::Updated)->connect([&box](){
+  Vtk::ContainerBox v_box;
-    std::cout << "box updated: " << box.GetWorldPoint(HPoint3f(1,1,1)) << std::endl;
+  v_box.findOrAddSignal(&Object::Updated)->connect([&v_box]() {
+    std::cout << "box updated: "
+              << v_box.get()->GetWorldPoint(HPoint3f(1, 1, 1)) << std::endl;
   });
 
   if (std::getenv("CTEST_PROJECT_NAME") == nullptr) {

src/Vtk/Math/testing/vtkContainerBoxTest2.cpp

@@ -15,11 +15,11 @@ using namespace uLib;
 
 int main() {
     std::cout << "Creating ContainerBox..." << std::endl;
-    ContainerBox box(Vector3f(1.0, 1.0, 1.0)); // 1x1x1 unit box
+    ContainerBox* box = new ContainerBox(Vector3f(1.0, 1.0, 1.0)); // 1x1x1 unit box
-    box.SetInstanceName("MyTestBox");
+    box->SetInstanceName("MyTestBox");
 
     std::cout << "Creating VTK representation..." << std::endl;
-    Vtk::ContainerBox v_box(&box);
+    Vtk::ContainerBox v_box(box);
     v_box.SetRepresentation(Vtk::Prop3D::Wireframe);
     v_box.SetColor(1.0, 0.0, 0.0); // Red
 

src/Vtk/Math/vtkAssembly.cpp

@@ -45,15 +45,13 @@ Assembly::Assembly(uLib::Assembly *content)
 
 Assembly::~Assembly() {
     delete m_ChildContext;
-    if (m_BBoxActor)  m_BBoxActor->Delete();
-    if (m_VtkAsm)     m_VtkAsm->Delete();
 }
 
 // ------------------------------------------------------------------ //
 void Assembly::InstallPipe() {
-    // 1. Create the VTK library assembly that groups everything
+    // 1. Setup the internal VTK assembly
-    m_VtkAsm = ::vtkAssembly::New();
+    m_VtkAsm = vtkSmartPointer<::vtkAssembly>::New();
-    m_VtkAsm->PickableOff();
+    m_BBoxActor = vtkSmartPointer<::vtkActor>::New();
     this->SetProp(m_VtkAsm);
 
     // 2. Create the bounding-box wireframe actor
@@ -64,7 +62,6 @@ void Assembly::InstallPipe() {
     vtkNew<vtkPolyDataMapper> mapper;
     mapper->SetInputConnection(cube->GetOutputPort());
 
-    m_BBoxActor = vtkActor::New();
     m_BBoxActor->SetMapper(mapper);
     m_BBoxActor->GetProperty()->SetRepresentationToWireframe();
     m_BBoxActor->GetProperty()->SetColor(1.0, 0.85, 0.0);   // gold wireframe
@@ -93,14 +90,7 @@ void Assembly::Update() {
     if (m_InUpdate) return;
     m_InUpdate = true;
     
-    if (this->m_model && m_VtkAsm) {
+    // Delegate to Prop3D to handle standard transformation application (uses GetContent())
-        // Apply world matrix from the assembly content
-        vtkNew<vtkMatrix4x4> m;
-        Matrix4fToVtk(this->m_model->GetMatrix(), m);
-        m_VtkAsm->SetUserMatrix(m);
-        m_VtkAsm->Modified();
-    }
-
     this->Prop3D::Update();
     this->UpdateBoundingBox();
     if (m_ChildContext)
@@ -110,25 +100,29 @@ void Assembly::Update() {
 
 void Assembly::SyncFromVtk() {
     if (m_InUpdate) return;
-    if (!this->m_model || !m_VtkAsm) return;
-
     m_InUpdate = true;
     
-    // VTK -> Model: Update world matrix (accounting for model parents)
+    // Sync the group-level transformation from VTK to the domain model
-    if (vtkProp3D* proxy = this->GetProxyProp()) {
+    this->Prop3D::SyncFromVtk();
-        this->m_model->SetWorldMatrix(VtkToMatrix4f(proxy->GetUserMatrix()));
-        this->m_model->FromMatrix(this->m_model->GetMatrix());
-    }
     
-    this->UpdateBoundingBox();
+    // Propagate sync to children
     if (m_ChildContext)
         m_ChildContext->SyncFromVtk();
     
-    this->m_model->Updated(); // Notify change in model
-
     m_InUpdate = false;
 }
 
+
+void Assembly::serialize_display(uLib::Archive::display_properties_archive &ar, const unsigned int version) {
+    // 1. Register base class appearance/transform
+    this->Prop3D::serialize_display(ar, version);
+
+    // 2. Map domain model properties (Bounding Box visibility, etc.)
+    if (this->m_model) {
+        ar & HRP("ShowBoundingBox", m_model->m_ShowBoundingBox);
+    }
+}
+
 // ------------------------------------------------------------------ //
 void Assembly::UpdateBoundingBox() {
     if (!this->m_model || !m_BBoxActor) return;
@@ -188,10 +182,6 @@ void Assembly::UpdateBoundingBox() {
     m_BBoxActor->Modified();
 }
 
-// ------------------------------------------------------------------ //
-ObjectsContext *Assembly::GetChildrenContext() const {
-    return m_ChildContext;
-}
 
 } // namespace Vtk
 } // namespace uLib

src/Vtk/Math/vtkAssembly.h

@@ -16,8 +16,9 @@
 #include "Math/Assembly.h"
 #include "Vtk/uLibVtkInterface.h"
 
-class vtkActor;
+#include <vtkSmartPointer.h>
-class vtkAssembly;  // VTK library forward declaration (must be before namespace)
+#include <vtkActor.h>
+#include <vtkAssembly.h>
 
 namespace uLib {
 namespace Vtk {
@@ -39,33 +40,36 @@ class Assembly : public Prop3D, public uLib::ObjectWrapper<uLib::Assembly> {
 public:
     uLibTypeMacro(Assembly, Prop3D)
 
-    Assembly(uLib::Assembly *content);
+    /**
+     * @brief Constructor.
+     * @param content Pointer to the domain assembly model.
+     */
+    explicit Assembly(uLib::Assembly *content);
     virtual ~Assembly();
 
     /** @brief Updates the VTK representation from the model (model→VTK). */
     virtual void Update() override;
 
-    /** @brief Synchronizes the model from the VTK representation (VTK→model). */
     virtual void SyncFromVtk() override;
 
     virtual uLib::Object* GetContent() const override { return (uLib::Object*)m_model.get(); }
     virtual uLib::ObjectsContext* GetChildren() override { return (uLib::ObjectsContext*)m_model.get(); }
 
-    /**
+    /** @brief Returns the visualization context for children. */
-     * @brief Returns the prop3d managing child objects.
+    uLib::Vtk::ObjectsContext* GetChildrenContext() const { return m_ChildContext; }
-     */
 
-    /** @brief Returns the prop3d managing child objects. */
+    /** @brief Property serialization for Display Properties Panel. */
-    ObjectsContext *GetChildrenContext() const;
+    void serialize_display(Archive::display_properties_archive &ar, const unsigned int version = 0) override;
 
 private:
     void UpdateBoundingBox();
     void InstallPipe();
 
-    ObjectsContext  *m_ChildContext;
+    vtkSmartPointer<::vtkAssembly>    m_VtkAsm;
-    vtkActor           *m_BBoxActor;
+    vtkSmartPointer<::vtkActor>       m_BBoxActor;
-    ::vtkAssembly      *m_VtkAsm; // VTK library assembly — NOT this class
+
-    bool                m_InUpdate;    // re-entrancy guard
+    uLib::Vtk::ObjectsContext *m_ChildContext;
+    bool m_InUpdate;
 };
 
 } // namespace Vtk

src/Vtk/Math/vtkContainerBox.cpp

@@ -43,50 +43,45 @@
 
 #include "Vtk/Math/vtkDense.h"
 
-
 namespace uLib {
 namespace Vtk {
 
 struct ContainerBoxData {
-  vtkSmartPointer<vtkActor>     m_Cube;
+  vtkSmartPointer<vtkActor> m_Cube;
-  vtkSmartPointer<vtkActor>     m_Axes;
+  vtkSmartPointer<vtkActor> m_Axes;
-  vtkSmartPointer<vtkAssembly>  m_VtkAsm;
+  vtkSmartPointer<vtkAssembly> m_VtkAsm;
-  uLib::Connection              m_UpdateSignal;
+  uLib::Connection m_UpdateSignal;
 
-
+  ContainerBoxData()
-  ContainerBoxData() : m_Cube(vtkSmartPointer<vtkActor>::New()), 
+      : m_Cube(vtkSmartPointer<vtkActor>::New()),
-                       m_Axes(vtkSmartPointer<vtkActor>::New()), 
+        m_Axes(vtkSmartPointer<vtkActor>::New()),
-                       m_VtkAsm(vtkSmartPointer<vtkAssembly>::New()) {}
+        m_VtkAsm(vtkSmartPointer<vtkAssembly>::New()) {}
   ~ContainerBoxData() {
+    m_UpdateSignal.disconnect();
   }
 };
 
-
-
-
-
 ContainerBox::ContainerBox(ContainerBox::Content *content)
-    : d(new ContainerBoxData()), ObjectWrapper(content) {
+    : d(new ContainerBoxData()),
+      ObjectWrapper(content ? content : new Content()) {
   this->InstallPipe();
-  d->m_UpdateSignal =
+  d->m_UpdateSignal = Object::connect(
-      Object::connect(this->m_model.get(), &uLib::Object::Updated, this, &ContainerBox::Update);
+      this->m_model.get(), &uLib::Object::Updated, this, &ContainerBox::Update);
 }
 
-ContainerBox::~ContainerBox() {
+ContainerBox::~ContainerBox() { delete d; }
-  delete d;
-}
 
 vtkPolyData *ContainerBox::GetPolyData() const {
   // TODO
   return NULL;
 }
 
-
 void ContainerBox::Update() {
   RecursiveMutex::ScopedLock lock(this->m_UpdateMutex);
-  if (!this->m_model) return;
+  if (!this->m_model)
+    return;
 
-  vtkProp3D* prop = vtkProp3D::SafeDownCast(this->GetProp());
+  vtkProp3D *prop = vtkProp3D::SafeDownCast(this->GetProp());
   if (prop) {
     // Apply the full volume matrix (TRS * m_LocalT)
     vtkNew<vtkMatrix4x4> m;
@@ -102,30 +97,6 @@ void ContainerBox::Update() {
 
 
 
-
-void ContainerBox::SyncFromVtk() {
-  RecursiveMutex::ScopedLock lock(this->m_UpdateMutex);
-  if (!this->m_model) return;
-
-  vtkProp3D* root = this->GetProxyProp();
-  if (!root) return;
-
-  // VTK -> Model: Extract new world TRS from proxy, which matches the model's TRS center
-  vtkMatrix4x4* rootMat = root->GetUserMatrix();
-  Matrix4f vtkWorld = VtkToMatrix4f(rootMat);
-  
-  // Synchronize TRS property members from the updated local matrix
-  this->m_model->FromMatrix(vtkWorld);
-
-  // Since we modified the model, notify observers, but block the loop back to VTK
-  // ConnectionBlock blocker(d->m_UpdateSignal);
-  this->m_model->Updated();
-}
-
-
-
-
-
 void ContainerBox::InstallPipe() {
   if (!this->m_model)
     return;

src/Vtk/Math/vtkContainerBox.h

@@ -42,11 +42,11 @@ class ContainerBox : public Prop3D,
                      public Polydata,
                      public uLib::ObjectWrapper<uLib::ContainerBox> {
 
-  uLibTypeMacro(ContainerBox, Prop3D, Polydata)
+  uLibTypeMacro(ContainerBox, Prop3D,
-  typedef uLib::ContainerBox Content;
+                Polydata) typedef uLib::ContainerBox Content;
 
 public:
-  ContainerBox(Content *content);
+  ContainerBox(Content *content = nullptr);
   ~ContainerBox();
 
   virtual class vtkPolyData *GetPolyData() const override;
@@ -59,7 +59,7 @@ public:
   /**
    * @brief Synchronizes the model from the VTK representation (VTK→model).
    */
-  virtual void SyncFromVtk() override;
+
 
   virtual uLib::Object *GetContent() const override {
     return (uLib::Object *)m_model.get();

src/Vtk/Math/vtkCylinder.cpp

@@ -44,8 +44,7 @@ Cylinder::Cylinder(Cylinder::Content *content)
 }
 
 Cylinder::~Cylinder() {
-  if (m_Actor) m_Actor->Delete();
+  m_UpdateSignal.disconnect();
-  if (m_VtkAsm) m_VtkAsm->Delete();
 }
 
 void Cylinder::Update() {
@@ -85,26 +84,13 @@ void Cylinder::Update() {
   this->Prop3D::Update();
 }
 
-void Cylinder::SyncFromVtk() {
-  if (!this->m_model) return;
 
-  vtkProp3D* root = this->GetProxyProp();
-  if (!root) return;
-
-  // VTK -> Model: Extract new world TRS from proxy
-  vtkMatrix4x4* rootMat = root->GetUserMatrix();  
-  Matrix4f vtkWorld = VtkToMatrix4f(rootMat);
-  
-  // Directly sync model from the world matrix
-  this->m_model->FromMatrix(vtkWorld);
-  this->m_model->Updated(); 
-}
 
 void Cylinder::InstallPipe() {
   if (!this->m_model)
     return;
 
-  m_VtkAsm = ::vtkAssembly::New();
+  m_VtkAsm = vtkSmartPointer<::vtkAssembly>::New();
   this->SetProp(m_VtkAsm);
 
   vtkNew<vtkCylinderSource> cylinder;
@@ -112,7 +98,7 @@ void Cylinder::InstallPipe() {
   cylinder->SetHeight(1.0);
   cylinder->SetResolution(32);
 
-  m_Actor = vtkActor::New();
+  m_Actor = vtkSmartPointer<vtkActor>::New();
   vtkNew<vtkTransform> alignment;
   m_Actor->SetUserTransform(alignment);
 

src/Vtk/Math/vtkCylinder.h

@@ -30,6 +30,7 @@
 #include "Math/Cylinder.h"
 #include "Vtk/uLibVtkInterface.h"
 #include <vtkActor.h>
+#include <vtkSmartPointer.h>
 class vtkAssembly;
 
 namespace uLib {
@@ -53,7 +54,7 @@ public:
   virtual void Update() override;
 
   /** Synchronizes the uLib model matrix with the VTK actor specifically for gizmo interactions */
-  virtual void SyncFromVtk() override;
+
 
   virtual uLib::Object *GetContent() const override {
     return (uLib::Object *)m_model.get();
@@ -63,8 +64,8 @@ protected:
   /** Sets up the VTK visualization pipeline */
   virtual void InstallPipe();
 
-  vtkActor *m_Actor;
+  vtkSmartPointer<vtkActor> m_Actor;
-  ::vtkAssembly *m_VtkAsm;
+  vtkSmartPointer<::vtkAssembly> m_VtkAsm;
   uLib::Connection m_UpdateSignal;
 };
 

src/Vtk/Math/vtkQuadMesh.h

@@ -54,11 +54,11 @@ public:
 
   void ReadFromStlFile(const char *filename);
 
-  virtual class vtkPolyData *GetPolyData() const;
+  vtkPolyData *GetPolyData() const override;
 
   virtual void contentUpdate();
 
-  virtual void Update();
+  void Update() override;
   uLib::Object *GetContent() const override {
     return (uLib::Object *)m_model.get();
   }

src/Vtk/Math/vtkTriangleMesh.h

@@ -54,11 +54,11 @@ public:
 
   void ReadFromStlFile(const char *filename);
 
-  virtual class vtkPolyData *GetPolyData() const;
+  vtkPolyData *GetPolyData() const override;
 
   virtual void contentUpdate();
 
-  virtual void Update();
+  void Update() override;
   uLib::Object *GetContent() const override {
     return (uLib::Object *)m_model.get();
   }

src/Vtk/Math/vtkVoxImage.cpp

@@ -308,17 +308,7 @@ void VoxImage::serialize_display(uLib::Archive::display_properties_archive & ar,
       {"MIP", "Composite", "Composite Shaded", "MIP Bone", "MIP Hot", "Additive"});
 }
 
-void VoxImage::SyncFromVtk() {
+
-  if (auto *root = this->GetProxyProp()) {
-    vtkMatrix4x4 *rootMat = root->GetUserMatrix();
-    if (rootMat) {
-      Matrix4f vtkLocal = VtkToMatrix4f(rootMat);
-      // Synchronize TRS from VTK, compensating for local volume offset
-      this->m_model->FromMatrix(vtkLocal); // * this->m_model->GetLocalMatrix().inverse());
-      this->m_model->Updated();
-    }
-  }
-}
 
 void VoxImage::Update() {
   if (auto *root = vtkProp3D::SafeDownCast(this->GetProp())) {

src/Vtk/Math/vtkVoxImage.h

@@ -77,7 +77,7 @@ public:
   void RescaleShaderRange();
 
   void Update() override;
-  void SyncFromVtk() override;
+
   void serialize_display(uLib::Archive::display_properties_archive &ar,
                          const unsigned int version = 0) override;
 

src/Vtk/testing/Prop3DPropertyTest.cpp

@@ -11,6 +11,7 @@
 
 #include "Vtk/uLibVtkInterface.h"
 #include "Core/Property.h"
+#include "Math/Dense.h"
 #include <iostream>
 #include <cassert>
 #include "testing-prototype.h"
@@ -33,7 +34,7 @@ int main() {
     
     // Verify specific properties exist
     Property<double>* opacityProp = nullptr;
-    Property<double>* colorRProp = nullptr;
+    Property<Vector3d>* colorProp = nullptr;
     
     for (auto* prop : props) {
         std::cout << "  - [" << prop->GetTypeName() << "] " << prop->GetName() 
@@ -42,13 +43,13 @@ int main() {
         if (prop->GetName() == "Opacity") {
             opacityProp = dynamic_cast<Property<double>*>(prop);
         }
-        if (prop->GetName() == "ColorR") {
+        if (prop->GetName() == "Color") {
-            colorRProp = dynamic_cast<Property<double>*>(prop);
+            colorProp = dynamic_cast<Property<Vector3d>*>(prop);
         }
     }
     
     assert(opacityProp != nullptr && "Opacity property not registered!");
-    assert(colorRProp != nullptr && "ColorR property not registered!");
+    assert(colorProp != nullptr && "Color property not registered!");
 
     // Test modification via uLib Property interface
     std::cout << "Modifying Opacity via property proxy (0.25)..." << std::endl;
@@ -58,9 +59,9 @@ int main() {
     assert(opacityProp->Get() == 0.25);
     assert(opacityProp->GetValueAsString().find("0.25") != std::string::npos);
 
-    std::cout << "Modifying ColorR via property proxy (0.9)..." << std::endl;
+    std::cout << "Modifying Color via property proxy (0.9, 0.1, 0.1)..." << std::endl;
-    *colorRProp = 0.9;
+    *colorProp = Vector3d(0.9, 0.1, 0.1);
-    assert(colorRProp->Get() == 0.9);
+    assert(colorProp->Get().x() == 0.9);
 
     std::cout << "All Prop3D Property Registration Tests PASSED!" << std::endl;
 

src/Vtk/uLibVtkInterface.cxx

@@ -93,14 +93,28 @@ public:
         m_Selectable(true),
         m_Selected(false),
         m_Visibility(true),
-        m_Dragable(true)
+        m_Dragable(true),
+        m_HighlightMode(Prop3D::HighlightPlain)
     {
         m_Color = Vector3d(-1, -1, -1);
+        m_PrevMatrix = vtkSmartPointer<vtkMatrix4x4>::New();
+        m_PrevMatrix->Identity();
     }
 
     ~Prop3DData() {
-        // No manual Delete needed for smart pointers
+        if (m_Renderers) {
-
+            m_Renderers->InitTraversal();
+            for (int i = 0; i < m_Renderers->GetNumberOfItems(); ++i) {
+                vtkRenderer* ren = m_Renderers->GetNextItem();
+                if (ren) {
+                    if (m_Prop) ren->RemoveViewProp(m_Prop);
+                    if (m_OutlineActor) ren->RemoveActor(m_OutlineActor);
+                    if (m_CubeAxesActor) ren->RemoveActor(m_CubeAxesActor);
+                    if (m_HighlightActor) ren->RemoveActor(m_HighlightActor);
+                }
+            }
+            m_Renderers->RemoveAllItems();
+        }
     }
 
     Prop3D *m_Prop3D;
@@ -125,6 +139,10 @@ public:
     bool m_Visibility;
     bool m_Dragable;
 
+    int  m_HighlightMode; // 0: Plain, 1: Corners
+
+    vtkSmartPointer<vtkMatrix4x4> m_PrevMatrix;
+
     // 
     TRS m_Transform;
 
@@ -212,39 +230,71 @@ public:
             }
 
             if (!m_HighlightActor) {
+                m_HighlightActor = vtkSmartPointer<vtkActor>::New();
+                vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
+                m_HighlightActor->SetMapper(mapper);
+                m_HighlightActor->GetProperty()->SetRepresentationToWireframe();
+                m_HighlightActor->GetProperty()->SetColor(1.0, 0.0, 0.0); // Red
+                m_HighlightActor->GetProperty()->SetLineWidth(2.0);
+                m_HighlightActor->GetProperty()->SetLighting(0);
+            }
+
+            if (m_HighlightMode == Prop3D::HighlightPlain) {
                 vtkSmartPointer<vtkCubeSource> cube = vtkSmartPointer<vtkCubeSource>::New();
                 double bounds[6];
                 polydata->GetBounds(bounds);
-                // Add a small padding to prevent z-fighting
                 double maxDim = std::max({bounds[1]-bounds[0], bounds[3]-bounds[2], bounds[5]-bounds[4]});
                 double pad = maxDim * 0.02;
                 if(pad < 1e-4) pad = 0.05;
                 cube->SetBounds(bounds[0]-pad, bounds[1]+pad,
                                 bounds[2]-pad, bounds[3]+pad,
                                 bounds[4]-pad, bounds[5]+pad);
-
+                cube->Update();
-                m_HighlightActor = vtkSmartPointer<vtkActor>::New();
+                m_HighlightActor->GetMapper()->SetInputConnection(cube->GetOutputPort());
-                vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
-                mapper->SetInputConnection(cube->GetOutputPort());
-                m_HighlightActor->SetMapper(mapper);
-                m_HighlightActor->GetProperty()->SetRepresentationToWireframe();
-                m_HighlightActor->GetProperty()->SetColor(1.0, 0.0, 0.0); // Red
-                m_HighlightActor->GetProperty()->SetLineWidth(2.0);
-                m_HighlightActor->GetProperty()->SetLighting(0);
             } else {
-                if (auto* mapper = vtkPolyDataMapper::SafeDownCast(m_HighlightActor->GetMapper())) {
+                // Corners mode logic
-                    if (auto* cube = vtkCubeSource::SafeDownCast(mapper->GetInputAlgorithm())) {
+                double bounds[6];
-                        double bounds[6];
+                polydata->GetBounds(bounds);
-                        polydata->GetBounds(bounds);
+                double maxDim = std::max({bounds[1]-bounds[0], bounds[3]-bounds[2], bounds[5]-bounds[4]});
-                        double maxDim = std::max({bounds[1]-bounds[0], bounds[3]-bounds[2], bounds[5]-bounds[4]});
+                double pad = maxDim * 0.02;
-                        double pad = maxDim * 0.02;
+                if(pad < 1e-4) pad = 0.05;
-                        if(pad < 1e-4) pad = 0.05;
+                
-                        cube->SetBounds(bounds[0]-pad, bounds[1]+pad,
+                double b[6] = {bounds[0]-pad, bounds[1]+pad, bounds[2]-pad, bounds[3]+pad, bounds[4]-pad, bounds[5]+pad};
-                                        bounds[2]-pad, bounds[3]+pad,
+                
-                                        bounds[4]-pad, bounds[5]+pad);
+                vtkNew<vtkPoints> points;
-                        cube->Modified();
+                vtkNew<vtkCellArray> lines;
+                
+                float len[3] = {
+                    (float)(b[1] - b[0]) * 0.15f,
+                    (float)(b[3] - b[2]) * 0.15f,
+                    (float)(b[5] - b[4]) * 0.15f
+                };
+
+                for (int i = 0; i < 8; ++i) {
+                    double p[3];
+                    p[0] = b[(i & 1) ? 1 : 0];
+                    p[1] = b[(i & 2) ? 1 : 0];
+                    p[2] = b[(i & 4) ? 1 : 0];
+
+                    for (int axis = 0; axis < 3; ++axis) {
+                        double p2[3] = {p[0], p[1], p[2]};
+                        double delta = (i & (1 << axis)) ? -len[axis] : len[axis];
+                        p2[axis] += delta;
+
+                        vtkIdType id1 = points->InsertNextPoint(p);
+                        vtkIdType id2 = points->InsertNextPoint(p2);
+                        lines->InsertNextCell(2);
+                        lines->InsertCellPoint(id1);
+                        lines->InsertCellPoint(id2);
                     }
                 }
+
+                vtkNew<vtkPolyData> cornerPoly;
+                cornerPoly->SetPoints(points);
+                cornerPoly->SetLines(lines);
+                if (auto* mapper = vtkPolyDataMapper::SafeDownCast(m_HighlightActor->GetMapper())) {
+                    mapper->SetInputData(cornerPoly);
+                }
             }
 
             // Update highlight matrix from the model world matrix
@@ -254,6 +304,7 @@ public:
                         vtkNew<vtkMatrix4x4> vwm;
                         Matrix4fToVtk(tr->GetWorldMatrix(), vwm);
                         m_HighlightActor->SetUserMatrix(vwm);
+                        m_PrevMatrix->DeepCopy(vwm);
                     }
                 }
             }
@@ -290,9 +341,6 @@ public:
 
 Prop3D::Prop3D() : Object(), pd(new Prop3DData(this)) { 
     ULIB_ACTIVATE_DISPLAY_PROPERTIES;
-    for (auto* p : this->GetDisplayProperties()) {
-        uLib::Object::connect(p, &uLib::PropertyBase::Updated, this, &Prop3D::Update);
-    }
 }
 
 Prop3D::~Prop3D()
@@ -517,6 +565,12 @@ void Prop3D::SetRepresentation(const char *mode)
     else if (s == "slice") SetRepresentation(Slice);
 }
 
+void Prop3D::SetHighlightMode(HighlightMode mode)
+{
+    pd->m_HighlightMode = static_cast<int>(mode);
+    pd->UpdateHighlight();
+}
+
 void Prop3D::SetColor(double r, double g, double b)
 {
     pd->m_Color[0] = r;
@@ -531,6 +585,18 @@ void Prop3D::SetOpacity(double alpha)
     pd->ApplyAppearance(pd->m_Prop);
 }
 
+void Prop3D::GetColor(double &r, double &g, double &b) const
+{
+    r = pd->m_Color[0];
+    g = pd->m_Color[1];
+    b = pd->m_Color[2];
+}
+
+double Prop3D::GetOpacity() const
+{
+    return pd->m_Opacity;
+}
+
 
 
 
@@ -570,6 +636,7 @@ void Prop3D::ApplyProp3DTransform(vtkProp3D* prop)
             Matrix4fToVtk(tr->GetMatrix(), m);
             prop->SetUserMatrix(m);
             prop->Modified();
+            pd->m_PrevMatrix->DeepCopy(m);
         }
     }
 }
@@ -580,7 +647,18 @@ void Prop3D::SyncFromVtk()
         if (auto* tr = dynamic_cast<uLib::TRS*>(content)) {
             if (auto* proxy = this->GetProxyProp()) {
                 if (vtkMatrix4x4* mat = proxy->GetUserMatrix()) {
-                    tr->FromMatrix(VtkToMatrix4f(mat));
+                    // Calculate Delta: currentMatrix * Inv(m_PrevMatrix)
+                    vtkNew<vtkMatrix4x4> invPrev;
+                    vtkMatrix4x4::Invert(pd->m_PrevMatrix, invPrev);
+                    
+                    vtkNew<vtkMatrix4x4> delta;
+                    vtkMatrix4x4::Multiply4x4(mat, invPrev, delta);
+
+                    // Apply delta to world matrix
+                    Matrix4f nextWorldMatrix = VtkToMatrix4f(delta) * tr->GetWorldMatrix();
+                    tr->SetWorldMatrix(nextWorldMatrix);
+                    
+                    pd->m_PrevMatrix->DeepCopy(mat);
                     content->Updated();
                 }
             }
@@ -658,6 +736,8 @@ struct AppearanceProxy {
         ar & boost::serialization::make_hrp("Dragable", pd->m_Dragable);
         ar & boost::serialization::make_hrp("ShowBoundingBox", pd->m_ShowBoundingBox);
         ar & boost::serialization::make_hrp("ShowScaleMeasures", pd->m_ShowScaleMeasures);
+        ar & boost::serialization::make_hrp_enum("HighlightMode", 
+            pd->m_HighlightMode, {"Plain", "Corners"});
     }
 };
 

src/Vtk/uLibVtkInterface.h

@@ -86,8 +86,10 @@ public:
   void DisonnectViewer(Viewer *viewer);
 
   void SetColor(double r, double g, double b);
+  void GetColor(double &r, double &g, double &b) const;
 
   void SetOpacity(double alpha);
+  double GetOpacity() const;
 
   void SetSelectable(bool selectable = true);
   bool IsSelectable() const;
@@ -123,6 +125,12 @@ public:
   void SetRepresentation(Representation mode);
   void SetRepresentation(const char *mode);
 
+  enum HighlightMode {
+      HighlightPlain = 0,
+      HighlightCorners = 1
+  };
+  void SetHighlightMode(HighlightMode mode);
+
   virtual void PrintSelf(std::ostream &o) const;
 
   void ShowBoundingBox(bool show);
@@ -222,7 +230,7 @@ public:
 
       m_Prop3D->RegisterDisplayProperty(p);
       Vtk::Prop3D *prop3d = m_Prop3D;
-      uLib::Object::connect(p, &uLib::PropertyBase::Updated,
+      uLib::Object::connect(p, &uLib::Object::Updated,
                             [prop3d]() { prop3d->Update(); });
     }
   }
@@ -236,7 +244,7 @@ public:
           t.labels(), t.units() ? t.units() : "", GetCurrentGroup());
       m_Prop3D->RegisterDisplayProperty(p);
       Vtk::Prop3D *prop3d = m_Prop3D;
-      uLib::Object::connect(p, &uLib::PropertyBase::Updated,
+      uLib::Object::connect(p, &uLib::Object::Updated,
                             [prop3d]() { prop3d->Update(); });
     }
   }
@@ -295,7 +303,7 @@ public:
     if (m_Prop3D) {
       m_Prop3D->RegisterDisplayProperty(&p);
       Vtk::Prop3D *prop3d = m_Prop3D;
-      uLib::Object::connect(&p, &uLib::PropertyBase::Updated,
+      uLib::Object::connect(&p, &uLib::Object::Updated,
                             [prop3d]() { prop3d->Update(); });
     }
   }

src/Vtk/vtkMultiSelectionProp.cpp

@@ -0,0 +1,175 @@
+#include "uLibVtkInterface.h"
+#include "vtkMultiSelectionProp.h"
+#include <vtkActor.h>
+#include <vtkPolyDataMapper.h>
+#include <vtkCubeSource.h>
+#include <vtkProperty.h>
+#include <vtkMatrix4x4.h>
+#include <vtkRenderer.h>
+#include <vtkRendererCollection.h>
+#include "Math/Transform.h"
+#include "Vtk/Math/vtkDense.h"
+
+namespace uLib {
+namespace Vtk {
+
+MultiSelectionProp::MultiSelectionProp() : Prop3D() {
+    ((::uLib::Object*)this)->SetInstanceName("Selection Group");
+    m_PrevMatrix = vtkSmartPointer<vtkMatrix4x4>::New();
+    m_GroupHighlightActor = vtkSmartPointer<vtkActor>::New();
+    
+    vtkNew<vtkPolyDataMapper> mapper;
+    m_GroupHighlightActor->SetMapper(mapper);
+    m_GroupHighlightActor->GetProperty()->SetRepresentationToWireframe();
+    m_GroupHighlightActor->GetProperty()->SetLineWidth(2.0);
+    m_GroupHighlightActor->GetProperty()->SetLighting(0);
+    m_GroupHighlightActor->PickableOff();
+    
+    // Set default display color in Prop3D state
+    ((Prop3D*)this)->SetColor(0.0, 1.0, 0.0);
+}
+
+MultiSelectionProp::~MultiSelectionProp() {
+}
+
+MultiSelectionProp* MultiSelectionProp::Clone() const {
+    auto* copy = new MultiSelectionProp();
+    copy->SetMembers(this->m_Members);
+    ((::uLib::Object*)copy)->SetInstanceName(((::uLib::Object*)this)->GetInstanceName());
+    return copy;
+}
+
+void MultiSelectionProp::SetMembers(const std::vector<Prop3D*>& members) {
+    m_Members = members;
+    Update();
+    
+    // Reset prev matrix to current highlight position
+    if (m_GroupHighlightActor->GetUserMatrix()) {
+        m_PrevMatrix->DeepCopy(m_GroupHighlightActor->GetUserMatrix());
+    } else {
+        m_PrevMatrix->Identity();
+    }
+}
+
+void MultiSelectionProp::Update() {
+    if (m_Members.empty()) {
+        m_GroupHighlightActor->VisibilityOff();
+        return;
+    }
+    m_GroupHighlightActor->VisibilityOn();
+    double combinedBounds[6] = {VTK_DOUBLE_MAX, VTK_DOUBLE_MIN, 
+                                VTK_DOUBLE_MAX, VTK_DOUBLE_MIN, 
+                                VTK_DOUBLE_MAX, VTK_DOUBLE_MIN};
+
+    for (auto* member : m_Members) {
+        if (vtkProp* prop = member->GetProp()) {
+            double* b = prop->GetBounds();
+            if (b) {
+                for (int i = 0; i < 3; ++i) {
+                    if (b[2*i] < combinedBounds[2*i]) combinedBounds[2*i] = b[2*i];
+                    if (b[2*i+1] > combinedBounds[2*i+1]) combinedBounds[2*i+1] = b[2*i+1];
+                }
+            }
+        }
+    }
+
+    if (combinedBounds[0] > combinedBounds[1]) return;
+
+    vtkNew<vtkCubeSource> cube;
+    double maxDim = std::max({combinedBounds[1]-combinedBounds[0], 
+                              combinedBounds[3]-combinedBounds[2], 
+                              combinedBounds[5]-combinedBounds[4]});
+    double pad = maxDim * 0.02;
+    if (pad < 1e-4) pad = 0.05;
+
+    cube->SetBounds(combinedBounds[0]-pad, combinedBounds[1]+pad,
+                    combinedBounds[2]-pad, combinedBounds[3]+pad,
+                    combinedBounds[4]-pad, combinedBounds[5]+pad);
+    cube->Update();
+    
+    if (auto* mapper = vtkPolyDataMapper::SafeDownCast(m_GroupHighlightActor->GetMapper())) {
+        mapper->SetInputConnection(cube->GetOutputPort());
+    }
+
+    // Apply TRS from m_SelectionTransform
+    vtkNew<vtkMatrix4x4> trsMatrix;
+    Matrix4fToVtk(m_SelectionTransform.GetWorldMatrix(), trsMatrix);
+    m_GroupHighlightActor->SetUserMatrix(trsMatrix);
+
+    // Apply Display Properties (Color, Opacity)
+    double r, g, b;
+    ((Prop3D*)this)->GetColor(r, g, b);
+    m_GroupHighlightActor->GetProperty()->SetColor(r, g, b);
+    m_GroupHighlightActor->GetProperty()->SetOpacity(((Prop3D*)this)->GetOpacity());
+
+    // Update Prev Matrix for delta calculations
+    m_PrevMatrix->DeepCopy(trsMatrix);
+
+    // Ensure it's in the renderers
+    vtkRendererCollection* rens = ((Prop3D*)this)->GetRenderers();
+    rens->InitTraversal();
+    for (int i = 0; i < rens->GetNumberOfItems(); ++i) {
+        vtkRenderer* ren = rens->GetNextItem();
+        ren->AddActor(m_GroupHighlightActor);
+    }
+}
+
+void MultiSelectionProp::SyncFromVtk() {
+    if (m_Members.empty()) return;
+    
+    vtkMatrix4x4* currentMatrix = m_GroupHighlightActor->GetUserMatrix();
+    if (!currentMatrix) return;
+
+    // Calculate Delta: currentMatrix * Inv(m_PrevMatrix)
+    vtkNew<vtkMatrix4x4> invPrev;
+    vtkMatrix4x4::Invert(m_PrevMatrix, invPrev);
+    
+    vtkNew<vtkMatrix4x4> delta;
+    vtkMatrix4x4::Multiply4x4(currentMatrix, invPrev, delta);
+
+    // Apply delta to all members
+    for (auto* member : m_Members) {
+        if (auto* content = member->GetContent()) {
+            if (auto* tr = dynamic_cast<uLib::TRS*>(content)) {
+                vtkNew<vtkMatrix4x4> memberWorldMatrix;
+                Matrix4fToVtk(tr->GetWorldMatrix(), memberWorldMatrix);
+                
+                vtkNew<vtkMatrix4x4> nextWorldMatrix;
+                vtkMatrix4x4::Multiply4x4(delta, memberWorldMatrix, nextWorldMatrix);
+                
+                // Set the new world matrix.
+                if (tr->GetParent()) {
+                    Matrix4f invParentWorld = tr->GetParent()->GetWorldMatrix().inverse();
+                    Matrix4f nextLocalMatrix = invParentWorld * VtkToMatrix4f(nextWorldMatrix);
+                    tr->FromMatrix(nextLocalMatrix);
+                } else {
+                    tr->FromMatrix(VtkToMatrix4f(nextWorldMatrix));
+                }
+                member->Update();
+            }
+        }
+    }
+    
+    m_PrevMatrix->DeepCopy(currentMatrix);
+    m_SelectionTransform.FromMatrix(VtkToMatrix4f(currentMatrix));
+}
+
+vtkProp* MultiSelectionProp::GetProp() {
+    return m_GroupHighlightActor;
+}
+
+vtkProp3D* MultiSelectionProp::GetProxyProp() {
+    return m_GroupHighlightActor;
+}
+
+void MultiSelectionProp::serialize(Archive::property_register_archive &ar, const unsigned int version) {
+    ar & boost::serialization::make_nvp("Transform", m_SelectionTransform);
+}
+
+void MultiSelectionProp::serialize_display(uLib::Archive::display_properties_archive &ar, const unsigned int version) {
+    // Call base class to register standard display properties (Color, Opacity)
+    ((Prop3D*)this)->serialize_display(ar, version);
+}
+
+} // namespace Vtk
+} // namespace uLib

src/Vtk/vtkMultiSelectionProp.h

@@ -0,0 +1,61 @@
+#ifndef ULIB_VTK_MULTISELECTIONPROP_H
+#define ULIB_VTK_MULTISELECTIONPROP_H
+
+#include "uLibVtkInterface.h"
+#include "Math/Transform.h"
+#include <vector>
+#include <vtkSmartPointer.h>
+#include <vtkMatrix4x4.h>
+
+class vtkActor;
+class vtkProp;
+class vtkProp3D;
+
+namespace uLib {
+namespace Vtk {
+
+/**
+ * @class MultiSelectionProp
+ * @brief A proxy Prop3D that represents a group of selected Prop3Ds.
+ * It manages a combined highlight and propagates transformations to its members.
+ */
+class MultiSelectionProp : public Prop3D {
+public:
+    uLibTypeMacro(MultiSelectionProp, Prop3D)
+
+    MultiSelectionProp();
+    virtual ~MultiSelectionProp();
+
+    /** @brief Creates a new instance that is a copy of this one's selection state. */
+    MultiSelectionProp* Clone() const;
+
+    void SetMembers(const std::vector<Prop3D*>& members);
+    const std::vector<Prop3D*>& GetMembers() const { return m_Members; }
+
+    virtual void Update() override;
+    virtual void SyncFromVtk() override;
+
+    virtual vtkProp* GetProp() override;
+    virtual vtkProp3D* GetProxyProp() override;
+
+    // Serialization for Properties Panel (TRS)
+    void serialize(Archive::property_register_archive &ar, const unsigned int version);
+
+    // Serialization for Display Properties Panel (Color, Opacity)
+    void serialize_display(uLib::Archive::display_properties_archive &ar, const unsigned int version = 0) override;
+
+    virtual uLib::Object* GetContent() const override { return const_cast<MultiSelectionProp*>(this); }
+
+private:
+    std::vector<Prop3D*> m_Members;
+    uLib::TRS m_SelectionTransform;
+    vtkSmartPointer<vtkMatrix4x4> m_PrevMatrix;
+    vtkSmartPointer<vtkActor> m_GroupHighlightActor;
+
+    
+};
+
+} // namespace Vtk
+} // namespace uLib
+
+#endif // ULIB_VTK_MULTISELECTIONPROP_H

src/Vtk/vtkObjectsContext.cpp

@@ -26,15 +26,17 @@ ObjectsContext::ObjectsContext(uLib::ObjectsContext *context)
     : m_Context(context), m_Assembly(::vtkAssembly::New()) {
   this->SetProp(m_Assembly);
   if (m_Context) {
-    Object::connect(m_Context, &uLib::ObjectsContext::ObjectAdded, this,
+    m_AddedConnection = Object::connect(m_Context, &uLib::ObjectsContext::ObjectAdded, this,
                     &ObjectsContext::OnObjectAdded);
-    Object::connect(m_Context, &uLib::ObjectsContext::ObjectRemoved, this,
+    m_RemovedConnection = Object::connect(m_Context, &uLib::ObjectsContext::ObjectRemoved, this,
                     &ObjectsContext::OnObjectRemoved);
     this->Synchronize();
   }
 }
 
 ObjectsContext::~ObjectsContext() {
+  m_AddedConnection.disconnect();
+  m_RemovedConnection.disconnect();
   for (auto const &[obj, prop3d] : m_Prop3Ds) {
     delete prop3d;
   }
@@ -136,6 +138,10 @@ Prop3D *ObjectsContext::CreateProp3D(uLib::Object *obj) {
   if (!obj)
     return nullptr;
 
+  if (auto* p3d = dynamic_cast<Prop3D*>(obj)) {
+      return p3d;
+  }
+
   if (auto *vox = dynamic_cast<uLib::Abstract::VoxImage *>(obj)) {
     return new VoxImage(vox);
   } else if (auto *box = dynamic_cast<uLib::ContainerBox *>(obj)) {

src/Vtk/vtkObjectsContext.h

@@ -51,6 +51,8 @@ private:
   uLib::ObjectsContext *m_Context;
   std::map<uLib::Object*, Prop3D*> m_Prop3Ds;
   vtkAssembly *m_Assembly;
+  uLib::Connection m_AddedConnection;
+  uLib::Connection m_RemovedConnection;
 };
 
 } // namespace Vtk

src/Vtk/vtkQViewport.cpp

@@ -20,6 +20,8 @@ QViewport::QViewport(QWidget* parent)
     , m_VtkWidget(nullptr)
     , m_GridButton(nullptr)
     , m_ProjButton(nullptr)
+    , m_renderTimer(nullptr)
+    , m_renderPending(false)
 {
     // Build the layout – zero margins so VTK fills the entire widget
     auto* layout = new QVBoxLayout(this);
@@ -29,8 +31,14 @@ QViewport::QViewport(QWidget* parent)
     m_VtkWidget = new QVTKOpenGLNativeWidget(this);
     layout->addWidget(m_VtkWidget);
  
+    // Initialize render timer
+    m_renderTimer = new QTimer(this);
+    m_renderTimer->setSingleShot(true);
+    connect(m_renderTimer, &QTimer::timeout, this, &QViewport::doRender);
+ 
     // Grid Toggle Button
     m_GridButton = new QPushButton(m_VtkWidget);
+
     m_GridButton->setText("#");
     m_GridButton->setFixedSize(40, 40);
     m_GridButton->setToolTip("Toggle Grid");
@@ -96,6 +104,9 @@ QViewport::QViewport(QWidget* parent)
 
 QViewport::~QViewport()
 {
+    if (m_VtkWidget && m_VtkWidget->renderWindow()) {
+        m_VtkWidget->renderWindow()->RemoveRenderer(this->GetRenderer());
+    }
 }
 
 void QViewport::SetupPipeline()
@@ -112,10 +123,22 @@ void QViewport::SetupPipeline()
 
 void QViewport::Render()
 {
-    if (m_VtkWidget && m_VtkWidget->renderWindow())
+    if (!m_throttledRendering) {
-        m_VtkWidget->renderWindow()->Render();
+        doRender();
+        return;
+    }
+    if (m_renderPending) return;
+    m_renderPending = true;
+    m_renderTimer->start(16);
 }
  
+ void QViewport::doRender()
+ {
+     m_renderPending = false;
+     if (m_VtkWidget && m_VtkWidget->renderWindow())
+         m_VtkWidget->renderWindow()->Render();
+ }
+
 vtkRenderWindow* QViewport::GetRenderWindow()
 {
     return m_VtkWidget->renderWindow();

src/Vtk/vtkQViewport.h

@@ -4,6 +4,7 @@
 #include <QWidget>
 #include <QVTKOpenGLNativeWidget.h>
 #include <QPushButton>
+#include <QTimer>
 
 #include <vtkCornerAnnotation.h>
 #include <vtkOrientationMarkerWidget.h>
@@ -39,6 +40,9 @@ public:
     // Render scene
     virtual void Render() override;
 
+    void SetThrottledRendering(bool enabled) { m_throttledRendering = enabled; }
+    bool GetThrottledRendering() const { return m_throttledRendering; }
+
     // Direct access to VTK internals
     virtual vtkRenderWindow*            GetRenderWindow() override;
     virtual vtkRenderWindowInteractor*  GetInteractor() override;
@@ -46,20 +50,25 @@ public:
 
     virtual void OnSelectionChanged(Prop3D* p) override;
  
-protected:
+ protected:
-    virtual void resizeEvent(QResizeEvent* event) override;
+     virtual void resizeEvent(QResizeEvent* event) override;
  
-private slots:
+ private slots:
-    void onGridButtonClicked();
+     void onGridButtonClicked();
-    void onProjButtonClicked();
+     void onProjButtonClicked();
+     void doRender();
  
-private:
+ private:
-    void SetupPipeline();
+     void SetupPipeline();
+ 
+     QVTKOpenGLNativeWidget*             m_VtkWidget;
+     QPushButton*                        m_GridButton;
+     QPushButton*                        m_ProjButton;
+     QTimer*                             m_renderTimer;
+     bool                                m_renderPending = false;
+     bool                                m_throttledRendering = true;
+ };
 
-    QVTKOpenGLNativeWidget*             m_VtkWidget;
-    QPushButton*                        m_GridButton;
-    QPushButton*                        m_ProjButton;
-};
 
 } // namespace Vtk
 } // namespace uLib

src/Vtk/vtkViewport.cpp

@@ -36,6 +36,8 @@
 #include "Vtk/Math/vtkCylinder.h"
 #include "Math/Transform.h"
 #include "Vtk/Math/vtkAssembly.h"
+#include "vtkMultiSelectionProp.h"
+#include <vtkRendererCollection.h>
 
 namespace uLib {
 namespace Vtk {
@@ -69,6 +71,7 @@ struct ViewportData {
 Viewport::Viewport()
     : pv(new ViewportData())
     , m_GridAxis(Y)
+    , m_MultiSelectionProp(new MultiSelectionProp())
 {
 }
 
@@ -100,6 +103,10 @@ Viewport::~Viewport()
         pv->m_CameraWidget->Off();
         pv->m_CameraWidget->SetInteractor(nullptr);
     }
+    if (m_MultiSelectionProp) {
+        delete m_MultiSelectionProp;
+        m_MultiSelectionProp = nullptr;
+    }
     delete pv;
 }
 
@@ -192,6 +199,11 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
         pv->m_Renderer->SetLayer(0);
     }
 
+    // Connect MultiSelectionProp
+    if (m_MultiSelectionProp) {
+        m_MultiSelectionProp->ConnectRenderer(pv->m_Renderer);
+    }
+
     // Setup Handler Widget
     if (!std::getenv("CTEST_PROJECT_NAME")) {
         pv->m_HandlerWidget = vtkSmartPointer<HandlerWidget>::New();
@@ -206,8 +218,10 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
         widgetInteractionCallback->SetClientData(this);
         widgetInteractionCallback->SetCallback([](vtkObject*, unsigned long, void* clientdata, void*){
             auto* self = static_cast<Viewport*>(clientdata);
-            for (auto* p : self->m_Prop3Ds) {
+            if (self->m_SelectedProps.size() > 1 && self->m_MultiSelectionProp) {
-                if (p->IsSelected()) {
+                self->m_MultiSelectionProp->SyncFromVtk();
+            } else {
+                for (auto* p : self->m_SelectedProps) {
                     p->SyncFromVtk();
                 }
             }
@@ -222,6 +236,7 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
     clickCallback->SetCallback([](vtkObject* caller, unsigned long, void* clientdata, void*){
         auto* iren = static_cast<vtkRenderWindowInteractor*>(caller);
         auto* self = static_cast<Viewport*>(clientdata);
+        bool multiSelect = iren->GetShiftKey() != 0;
         
         int* pos = iren->GetEventPosition();
         self->pv->m_Picker->Pick(pos[0], pos[1], 0, self->pv->m_Renderer);
@@ -291,7 +306,7 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
                 }
             }
         }
-        self->SelectProp3D(target);
+        self->SelectProp3D(target, multiSelect);
     });
     iren->AddObserver(vtkCommand::LeftButtonPressEvent, clickCallback);
 
@@ -446,6 +461,11 @@ void Viewport::RegisterProp3D(Prop3D* p, bool isPart) {
     m_Prop3Ds.push_back(p);
     p->ConnectRenderer(pv->m_Renderer);
 
+    // Ensure m_MultiSelectionProp also has the same renderers
+    if (m_MultiSelectionProp) {
+        m_MultiSelectionProp->GetRenderers()->AddItem(pv->m_Renderer);
+    }
+
     // If it's a part of an assembly, we don't want to draw it twice.
     // Assembly itself already draws its parts. 
     // But we need ConnectRenderer above to allow highliting and property updates.
@@ -497,28 +517,59 @@ void Viewport::ObserveContext(ObjectsContext* ctx) {
     });
 }
 
-void Viewport::SelectProp3D(Prop3D* prop)
+void Viewport::SelectProp3D(Prop3D* prop, bool multi)
 {
-    for (auto* p : m_Prop3Ds) {
+    if (multi) {
-        p->SetSelected(p == prop);
+        if (prop) {
+            auto it = std::find(m_SelectedProps.begin(), m_SelectedProps.end(), prop);
+            if (it != m_SelectedProps.end()) {
+                prop->SetSelected(false);
+                m_SelectedProps.erase(it);
+            } else {
+                prop->SetSelected(true);
+                m_SelectedProps.push_back(prop);
+            }
+        }
+    } else {
+        for (auto* p : m_SelectedProps) {
+            p->SetSelected(false);
+        }
+        m_SelectedProps.clear();
+        if (prop) {
+            prop->SetSelected(true);
+            m_SelectedProps.push_back(prop);
+        }
     }
 
+    // Update HandlerWidget
     if (pv->m_HandlerWidget) {
-        if (prop) {
+        if (m_SelectedProps.empty()) {
-            vtkProp3D* prop3d = prop->GetProxyProp();
+            pv->m_HandlerWidget->SetEnabled(0);
+            pv->m_HandlerWidget->SetProp3D(nullptr);
+            if (m_MultiSelectionProp) m_MultiSelectionProp->SetMembers({});
+        } else if (m_SelectedProps.size() == 1) {
+            Prop3D* selected = m_SelectedProps[0];
+            vtkProp3D* prop3d = selected->GetProxyProp();
             if (prop3d) {
                 pv->m_HandlerWidget->SetProp3D(prop3d);
                 pv->m_HandlerWidget->SetEnabled(1);
-                pv->m_HandlerWidget->PlaceWidget(prop3d->GetBounds()); //TODO: FIX !
+                pv->m_HandlerWidget->PlaceWidget(prop3d->GetBounds());
             }
+            if (m_MultiSelectionProp) m_MultiSelectionProp->SetMembers({});
         } else {
-            pv->m_HandlerWidget->SetEnabled(0);
+            // Multi-selection
-            pv->m_HandlerWidget->SetProp3D(nullptr);
+            if (m_MultiSelectionProp) {
+                m_MultiSelectionProp->SetMembers(m_SelectedProps);
+                vtkProp3D* proxy = m_MultiSelectionProp->GetProxyProp();
+                pv->m_HandlerWidget->SetProp3D(proxy);
+                pv->m_HandlerWidget->SetEnabled(1);
+                pv->m_HandlerWidget->PlaceWidget(proxy->GetBounds());
+            }
         }
     }
     
     Render();
-    OnSelectionChanged(prop);
+    OnSelectionChanged(m_SelectedProps.empty() ? nullptr : m_SelectedProps.back());
 }
 
 void Viewport::SetGridVisible(bool visible)
@@ -657,5 +708,19 @@ void Viewport::UpdateGrid()
     pv->m_Annotation->SetText(1, gridLabel);
 }
 
+void Viewport::GroupSelection(uLib::ObjectsContext* targetCtx) {
+    if (!targetCtx || m_SelectedProps.size() <= 1 || !m_MultiSelectionProp) return;
+
+    // Clone the current multi-selection proxy
+    MultiSelectionProp* group = m_MultiSelectionProp->Clone();
+    
+    // Add it to the context
+    targetCtx->AddObject(group);
+    
+    // Select the new group and clear multi-selection
+    m_SelectedProps.clear();
+    SelectProp3D(group);
+}
+
 } // namespace Vtk
 } // namespace uLib

src/Vtk/vtkViewport.h

@@ -29,6 +29,7 @@ namespace Vtk {
 
 struct ViewportData;
 class HandlerWidget;
+class MultiSelectionProp;
 class ObjectsContext;
 
 /**
@@ -49,7 +50,11 @@ public:
     // Prop3D / prop management
     void AddProp3D(Prop3D &prop);
     void RemoveProp3D(Prop3D &prop);
-    void SelectProp3D(Prop3D *prop);
+    /** @brief Selects a specific Prop3D. If multi is true, it toggles selection in a group. */
+    void SelectProp3D(Prop3D* target, bool multi = false);
+
+    /** @brief Creates a persistent Selection Group from the current multi-selection. */
+    void GroupSelection(uLib::ObjectsContext* targetCtx);
     void addProp(vtkProp *prop);
     void RemoveProp(vtkProp *prop);
 
@@ -91,6 +96,8 @@ protected:
     struct ViewportData *pv;
     Axis                                         m_GridAxis;
     std::vector<Prop3D*>                         m_Prop3Ds;
+    std::vector<Prop3D*>                         m_SelectedProps;
+    MultiSelectionProp*                          m_MultiSelectionProp;
     std::map<uLib::Object*, Prop3D*>             m_ObjectToProp3D;
 };