diff --git a/src/Vtk/uLibVtkInterface.cxx b/src/Vtk/uLibVtkInterface.cxx
index 186a024..46f7b07 100644
--- a/src/Vtk/uLibVtkInterface.cxx
+++ b/src/Vtk/uLibVtkInterface.cxx
@@ -53,9 +53,12 @@
 #include <vtkRenderer.h>
 #include <vtkProperty.h>
 #include <vtkCamera.h>
-
+#include <vtkPolyData.h>
+#include <vtkFeatureEdges.h>
+#include <vtkTransform.h>
 
 #include "uLibVtkInterface.h"
+#include "vtkHandlerWidget.h"
 
 
 
@@ -78,36 +81,30 @@ namespace Vtk {
 class PuppetData {
 public:
     PuppetData() :
-        m_Renderers(vtkRendererCollection::New()),
-        m_Assembly(vtkPropAssembly::New()),
-        m_OutlineSource(NULL),
-        m_OutlineActor(NULL),
-        m_CubeAxesActor(NULL),
+        m_Renderers(vtkSmartPointer<vtkRendererCollection>::New()),
+        m_Assembly(vtkSmartPointer<vtkPropAssembly>::New()),
         m_ShowBoundingBox(false),
         m_ShowScaleMeasures(false),
         m_Representation(-1),
-        m_Opacity(-1.0)
+        m_Opacity(-1.0),
+        m_Selectable(true),
+        m_Selected(false)
     {
         m_Color[0] = m_Color[1] = m_Color[2] = -1.0;
     }
 
     ~PuppetData() {
-        m_Renderers->RemoveAllItems();
-        m_Assembly->GetParts()->RemoveAllItems();
-        m_Renderers->Delete();
-        m_Assembly->Delete();
-        if (m_OutlineSource) m_OutlineSource->Delete();
-        if (m_OutlineActor) m_OutlineActor->Delete();
-        if (m_CubeAxesActor) m_CubeAxesActor->Delete();
+        // No manual Delete needed for smart pointers
     }
 
     // members //
-    vtkRendererCollection *m_Renderers;
-    vtkPropAssembly       *m_Assembly;
+    vtkSmartPointer<vtkRendererCollection> m_Renderers;
+    vtkSmartPointer<vtkPropAssembly>       m_Assembly;
 
-    vtkOutlineSource      *m_OutlineSource;
-    vtkActor              *m_OutlineActor;
-    vtkCubeAxesActor      *m_CubeAxesActor;
+    vtkSmartPointer<vtkOutlineSource>      m_OutlineSource;
+    vtkSmartPointer<vtkActor>              m_OutlineActor;
+    vtkSmartPointer<vtkCubeAxesActor>      m_CubeAxesActor;
+    vtkSmartPointer<vtkActor>              m_HighlightActor;
 
     bool m_ShowBoundingBox;
     bool m_ShowScaleMeasures;
@@ -132,6 +129,69 @@ public:
             actor->GetProperty()->SetOpacity(m_Opacity);
         }
     }
+
+    void UpdateHighlight() {
+        if (m_Selected) {
+            if (!m_HighlightActor) {
+                vtkSmartPointer<vtkFeatureEdges> edges = vtkSmartPointer<vtkFeatureEdges>::New();
+                edges->BoundaryEdgesOn();
+                edges->FeatureEdgesOn();
+                edges->SetFeatureAngle(30);
+                edges->NonManifoldEdgesOn();
+                edges->ManifoldEdgesOff();
+
+                // Find first polydata in assembly to highlight
+                vtkPropCollection *parts = m_Assembly->GetParts();
+                parts->InitTraversal();
+                for (int i = 0; i < parts->GetNumberOfItems(); ++i) {
+                    vtkActor *actor = vtkActor::SafeDownCast(parts->GetNextProp());
+                    if (actor && actor->GetMapper() && actor->GetMapper()->GetDataSetInput()) {
+                        edges->SetInputData(vtkPolyData::SafeDownCast(actor->GetMapper()->GetDataSetInput()));
+                        break;
+                    }
+                }
+
+                m_HighlightActor = vtkSmartPointer<vtkActor>::New();
+                vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
+                mapper->SetInputConnection(edges->GetOutputPort());
+                m_HighlightActor->SetMapper(mapper);
+                m_HighlightActor->GetProperty()->SetColor(1.0, 0.5, 0.0); // Orange
+                m_HighlightActor->GetProperty()->SetLineWidth(2.0);
+                m_HighlightActor->GetProperty()->SetLighting(0);
+            }
+
+            // Update highlight data and transform from first actor
+            vtkPropCollection *parts = m_Assembly->GetParts();
+            parts->InitTraversal();
+            for (int i = 0; i < parts->GetNumberOfItems(); ++i) {
+                vtkActor *actor = vtkActor::SafeDownCast(parts->GetNextProp());
+                if (actor) {
+                    // Sync transform
+                    m_HighlightActor->SetUserTransform(actor->GetUserTransform());
+                    m_HighlightActor->SetPosition(actor->GetPosition());
+                    m_HighlightActor->SetOrientation(actor->GetOrientation());
+                    m_HighlightActor->SetScale(actor->GetScale());
+                    break;
+                }
+            }
+
+            m_Renderers->InitTraversal();
+            for (int i = 0; i < m_Renderers->GetNumberOfItems(); ++i) {
+                vtkRenderer *ren = m_Renderers->GetNextItem();
+                ren->AddActor(m_HighlightActor);
+            }
+        } else {
+            if (m_HighlightActor) {
+                m_Renderers->InitTraversal();
+                for (int i = 0; i < m_Renderers->GetNumberOfItems(); ++i) {
+                    m_Renderers->GetNextItem()->RemoveActor(m_HighlightActor);
+                }
+            }
+        }
+    }
+
+    bool m_Selectable;
+    bool m_Selected;
 };
 
 // -------------------------------------------------------------------------- //
@@ -195,6 +255,10 @@ void Puppet::ConnectRenderer(vtkRenderer *renderer)
             d->m_CubeAxesActor->SetCamera(renderer->GetActiveCamera());
             renderer->AddActor(d->m_CubeAxesActor);
         }
+
+        if (d->m_Selected && d->m_HighlightActor) {
+            renderer->AddActor(d->m_HighlightActor);
+        }
     }
 }
 
@@ -248,8 +312,8 @@ void Puppet::ShowBoundingBox(bool show)
     d->m_ShowBoundingBox = show;
     if (show) {
         if (!d->m_OutlineActor) {
-            d->m_OutlineSource = vtkOutlineSource::New();
-            d->m_OutlineActor = vtkActor::New();
+            d->m_OutlineSource = vtkSmartPointer<vtkOutlineSource>::New();
+            d->m_OutlineActor = vtkSmartPointer<vtkActor>::New();
             vtkSmartPointer<vtkPolyDataMapper> mapper = vtkSmartPointer<vtkPolyDataMapper>::New();
             mapper->SetInputConnection(d->m_OutlineSource->GetOutputPort());
             d->m_OutlineActor->SetMapper(mapper);
@@ -282,7 +346,7 @@ void Puppet::ShowScaleMeasures(bool show)
     d->m_ShowScaleMeasures = show;
     if (show) {
         if (!d->m_CubeAxesActor) {
-            d->m_CubeAxesActor = vtkCubeAxesActor::New();
+            d->m_CubeAxesActor = vtkSmartPointer<vtkCubeAxesActor>::New();
             d->m_CubeAxesActor->SetFlyModeToOuterEdges();
             d->m_CubeAxesActor->SetUseTextActor3D(1);
             d->m_CubeAxesActor->GetProperty()->SetColor(1.0, 1.0, 1.0);
@@ -363,8 +427,32 @@ void Puppet::SetOpacity(double alpha)
 
 
 
+void Puppet::SetSelectable(bool selectable)
+{
+    d->m_Selectable = selectable;
+}
 
+bool Puppet::IsSelectable() const
+{
+    return d->m_Selectable;
+}
 
+void Puppet::SetSelected(bool selected)
+{
+    if (!d->m_Selectable) return;
+    if (d->m_Selected == selected) return;
+    d->m_Selected = selected;
+    d->UpdateHighlight();
+}
 
-} // Vtk
-} // uLib
+bool Puppet::IsSelected() const
+{
+    return d->m_Selected;
+}
+
+void Puppet::ConnectInteractor(vtkRenderWindowInteractor *interactor)
+{
+}
+
+} // namespace Vtk
+} // namespace uLib
diff --git a/src/Vtk/uLibVtkInterface.h b/src/Vtk/uLibVtkInterface.h
index c3127fc..4ae43f1 100644
--- a/src/Vtk/uLibVtkInterface.h
+++ b/src/Vtk/uLibVtkInterface.h
@@ -80,11 +80,13 @@ public:
 
   void SetOpacity(double alpha);
 
+  void SetSelectable(bool selectable = true);
+  bool IsSelectable() const;
 
-  
-  virtual void ConnectInteractor(class vtkRenderWindowInteractor *interactor) {
-    (void)interactor;
-  }
+  void SetSelected(bool selected = true);
+  bool IsSelected() const;
+
+  virtual void ConnectInteractor(class vtkRenderWindowInteractor *interactor);
 
 protected:
   void SetProp(vtkProp *prop);
@@ -92,6 +94,9 @@ protected:
   void RemoveProp(vtkProp *prop);
 
 private:
+  Puppet(const Puppet&) = delete;
+  Puppet& operator=(const Puppet&) = delete;
+
   friend class PuppetData;
   class PuppetData *d;
 };
diff --git a/src/Vtk/uLibVtkViewer.cpp b/src/Vtk/uLibVtkViewer.cpp
index 510d051..a67365b 100644
--- a/src/Vtk/uLibVtkViewer.cpp
+++ b/src/Vtk/uLibVtkViewer.cpp
@@ -93,8 +93,9 @@ void Viewer::InstallPipe() {
 }
 
 void Viewer::UninstallPipe() {
-  m_Renderer->RemoveAllViewProps();
-  m_Renderer->Clear();
+  if (m_Renderer) {
+    m_Renderer->RemoveAllViewProps();
+  }
 }
 
 void Viewer::Render() {
diff --git a/src/Vtk/vtkHandlerWidget.h b/src/Vtk/vtkHandlerWidget.h
index 6bc1a28..dfdea55 100644
--- a/src/Vtk/vtkHandlerWidget.h
+++ b/src/Vtk/vtkHandlerWidget.h
@@ -98,6 +98,8 @@ public:
   void SetTransform(::vtkTransform *t);
   void GetTransform(::vtkTransform *t);
 
+  ::vtkRenderer *GetOverlayRenderer() { return this->m_OverlayRenderer; }
+
 protected:
   void CreateGizmos();
   void UpdateGizmoPosition();
diff --git a/src/Vtk/vtkViewport.cpp b/src/Vtk/vtkViewport.cpp
index 66e7b50..a20f55f 100644
--- a/src/Vtk/vtkViewport.cpp
+++ b/src/Vtk/vtkViewport.cpp
@@ -1,6 +1,9 @@
 #include "vtkViewport.h"
-
+#include <vtkPropAssembly.h>
+#include <vtkPropCollection.h>
+#include <vtkProp3D.h>
 #include <vtkCamera.h>
+#include <algorithm>
 #include <vtkInteractorStyleTrackballCamera.h>
 #include <vtkObjectFactory.h>
 #include <vtkRenderWindow.h>
@@ -14,6 +17,8 @@
 #include <vtkCallbackCommand.h>
 #include <vtkMath.h>
 #include <cmath>
+#include <iostream>
+#include "vtkHandlerWidget.h"
 
 namespace uLib {
 namespace Vtk {
@@ -103,9 +108,94 @@ void Viewport::SetupPipeline(vtkRenderWindowInteractor* iren)
     m_CameraWidget->SetInteractor(iren);
     m_CameraWidget->On();
 #endif
-
     m_Renderer->SetBackground(0.15, 0.15, 0.15);
     m_Renderer->ResetCamera();
+
+    // Setup layering for overimposed rendering
+    if (iren->GetRenderWindow()) {
+        iren->GetRenderWindow()->SetNumberOfLayers(2);
+        m_Renderer->SetLayer(0);
+    }
+
+    // Setup Handler Widget
+    m_HandlerWidget = vtkSmartPointer<vtkHandlerWidget>::New();
+    m_HandlerWidget->SetInteractor(iren);
+    m_HandlerWidget->SetCurrentRenderer(m_Renderer);
+    if (m_HandlerWidget->GetOverlayRenderer()) {
+        m_HandlerWidget->GetOverlayRenderer()->SetLayer(1);
+    }
+
+    // Picking for selection
+    m_Picker = vtkSmartPointer<vtkCellPicker>::New();
+    vtkNew<vtkCallbackCommand> clickCallback;
+    clickCallback->SetClientData(this);
+    clickCallback->SetCallback([](vtkObject* caller, unsigned long, void* clientdata, void*){
+        auto* iren = static_cast<vtkRenderWindowInteractor*>(caller);
+        auto* self = static_cast<Viewport*>(clientdata);
+        
+        int* pos = iren->GetEventPosition();
+        self->m_Picker->Pick(pos[0], pos[1], 0, self->m_Renderer);
+        vtkProp* picked = self->m_Picker->GetViewProp();
+        
+        Puppet* target = nullptr;
+        if (picked) {
+            for (auto* p : self->m_Puppets) {
+                if (p->GetProp() == picked) {
+                    target = p;
+                    break;
+                }
+                auto* assembly = vtkPropAssembly::SafeDownCast(p->GetProp());
+                if (assembly) {
+                    bool found = false;
+                    auto* parts = assembly->GetParts();
+                    parts->InitTraversal();
+                    for (int i=0; i<parts->GetNumberOfItems(); ++i) {
+                        if (parts->GetNextProp() == picked) {
+                            found = true;
+                            break;
+                        }
+                    }
+                    if (found) {
+                        target = p;
+                        break;
+                    }
+                }
+            }
+        }
+        self->SelectPuppet(target);
+    });
+    iren->AddObserver(vtkCommand::LeftButtonPressEvent, clickCallback);
+
+    // Keyboard events for widget coordinate frame
+    vtkNew<vtkCallbackCommand> keyCallback;
+    keyCallback->SetClientData(this);
+    keyCallback->SetCallback([](vtkObject* caller, unsigned long, void* clientdata, void*){
+        auto* iren = static_cast<vtkRenderWindowInteractor*>(caller);
+        auto* self = static_cast<Viewport*>(clientdata);
+        
+        if (!self->m_HandlerWidget || !self->m_HandlerWidget->GetEnabled()) return;
+        
+        std::string key = iren->GetKeySym();
+        if (key == "l") {
+          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::LOCAL);
+          std::cout << "Widget Frame: LOCAL" << std::endl;
+        }
+        else if (key == "g") {
+          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::GLOBAL);
+          std::cout << "Widget Frame: GLOBAL" << std::endl;
+        }
+        else if (key == "c") {
+          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER);
+          std::cout << "Widget Frame: CENTER" << std::endl;
+        }
+        else if (key == "k") {
+          self->m_HandlerWidget->SetReferenceFrame(vtkHandlerWidget::CENTER_LOCAL);
+          std::cout << "Widget Frame: CENTER_LOCAL" << std::endl;
+        }
+        
+        iren->Render();
+    });
+    iren->AddObserver(vtkCommand::KeyPressEvent, keyCallback);
 }
 
 void Viewport::Reset()
@@ -124,17 +214,43 @@ void Viewport::ZoomAuto()
 
 void Viewport::AddPuppet(Puppet& prop)
 {
+    m_Puppets.push_back(&prop);
     prop.ConnectRenderer(m_Renderer);
-    prop.ConnectInteractor(GetInteractor());
     Render();
 }
 
 void Viewport::RemovePuppet(Puppet& prop)
 {
+    if (prop.IsSelected()) SelectPuppet(nullptr);
+    auto it = std::find(m_Puppets.begin(), m_Puppets.end(), &prop);
+    if (it != m_Puppets.end()) m_Puppets.erase(it);
     prop.DisconnectRenderer(m_Renderer);
     Render();
 }
 
+void Viewport::SelectPuppet(Puppet* prop)
+{
+    for (auto* p : m_Puppets) {
+        p->SetSelected(p == prop);
+    }
+    
+    if (m_HandlerWidget) {
+        if (prop) {
+            vtkProp3D* prop3d = vtkProp3D::SafeDownCast(prop->GetProp());
+            if (prop3d) {
+                m_HandlerWidget->SetProp3D(prop3d);
+                m_HandlerWidget->SetEnabled(1);
+                m_HandlerWidget->PlaceWidget(prop3d->GetBounds());
+            }
+        } else {
+            m_HandlerWidget->SetEnabled(0);
+            m_HandlerWidget->SetProp3D(nullptr);
+        }
+    }
+    
+    Render();
+}
+
 void Viewport::addProp(vtkProp* prop)
 {
     if (m_Renderer) {
diff --git a/src/Vtk/vtkViewport.h b/src/Vtk/vtkViewport.h
index 648720d..2d8424a 100644
--- a/src/Vtk/vtkViewport.h
+++ b/src/Vtk/vtkViewport.h
@@ -16,6 +16,8 @@
 #include <vtkAxesActor.h>
 #include <vtkPlaneSource.h>
 #include <vtkActor.h>
+#include <vtkCellPicker.h>
+#include <vector>
 
 class vtkProp;
 class vtk3DWidget;
@@ -26,6 +28,8 @@ class vtkCamera;
 namespace uLib {
 namespace Vtk {
 
+class vtkHandlerWidget;
+
 /**
  * @class Viewport
  * @brief Base class for VTK viewports, providing core rendering and prop management.
@@ -43,6 +47,7 @@ public:
     // Puppet / prop management
     void AddPuppet(Puppet &prop);
     void RemovePuppet(Puppet &prop);
+    void SelectPuppet(Puppet *prop);
     void addProp(vtkProp *prop);
     void RemoveProp(vtkProp *prop);
 
@@ -72,6 +77,10 @@ protected:
     vtkSmartPointer<vtkActor>            m_OriginAxesActor;
 
     vtkSmartPointer<vtkNamedColors>              m_Colors;
+    
+    vtkSmartPointer<vtkHandlerWidget>            m_HandlerWidget;
+    std::vector<Puppet*>                         m_Puppets;
+    vtkSmartPointer<vtkCellPicker>               m_Picker;
 };
 
 } // namespace Vtk