diff --git a/source/MaterialXRender/Util.cpp b/source/MaterialXRender/Util.cpp
index 00fdc65381..c206514412 100644
--- a/source/MaterialXRender/Util.cpp
+++ b/source/MaterialXRender/Util.cpp
@@ -318,7 +318,7 @@ void createUIPropertyGroups(DocumentPtr doc, const VariableBlock& block, UIPrope
 
         // Prepend a parent label for unlabeled node inputs.
         ElementPtr parent = pair.first->getParent();
-        if (item.ui.uiFolder.empty() && parent && parent->isA<Node>())
+        if (item.ui.uiName.empty() && parent && parent->isA<Node>())
         {
             item.label = parent->getName() + pathSeparator + item.label;
         }
diff --git a/source/MaterialXView/Editor.cpp b/source/MaterialXView/Editor.cpp
index abba9ce10e..6d64c55b30 100644
--- a/source/MaterialXView/Editor.cpp
+++ b/source/MaterialXView/Editor.cpp
@@ -18,11 +18,11 @@ namespace
 class EditorColorPicker : public ng::ColorPicker
 {
   public:
-    EditorColorPicker(ng::Widget* parent, const ng::Color& color) :
+    EditorColorPicker(ng::ref<ng::Widget> parent, const ng::Color& color) :
         ng::ColorPicker(parent, color)
     {
-        ng::Popup* popup = this->popup();
-        ng::Widget* floatGroup = new ng::Widget(popup);
+        ng::ref<ng::Popup> popup = this->popup();
+        ng::ref<ng::Widget> floatGroup = new ng::Widget(popup);
         auto layout = new ng::GridLayout(ng::Orientation::Horizontal, 2,
                                          ng::Alignment::Middle, 2, 2);
         layout->set_col_alignment({ ng::Alignment::Fill, ng::Alignment::Fill });
@@ -60,7 +60,7 @@ class EditorColorPicker : public ng::ColorPicker
 
   protected:
     // Additional numeric entry / feedback widgets
-    ng::FloatBox<float>* _colorWidgets[4];
+    ng::ref<ng::FloatBox<float>> _colorWidgets[4];
 };
 
 } // anonymous namespace
@@ -70,10 +70,6 @@ class EditorColorPicker : public ng::ColorPicker
 //
 
 PropertyEditor::PropertyEditor() :
-    _window(nullptr),
-    _container(nullptr),
-    _gridLayout2(nullptr),
-    _gridLayout3(nullptr),
     _visible(false),
     _fileDialogsForImages(true)
 {
@@ -81,7 +77,7 @@ PropertyEditor::PropertyEditor() :
 
 void PropertyEditor::create(Viewer& parent)
 {
-    ng::Window* parentWindow = parent.getWindow();
+    ng::ref<ng::Window> parentWindow = parent.getWindow();
 
     // Remove the window associated with the form.
     // This is done by explicitly creating and owning the window
@@ -110,7 +106,7 @@ void PropertyEditor::create(Viewer& parent)
     _window->set_position(previousPosition);
     _window->set_visible(_visible);
 
-    ng::VScrollPanel* scroll_panel = new ng::VScrollPanel(_window);
+    ng::ref<ng::VScrollPanel> scroll_panel = new ng::VScrollPanel(_window);
     scroll_panel->set_fixed_height(300);
     _container = new ng::Widget(scroll_panel);
     _container->set_layout(new ng::GroupLayout(1, 1, 1, 1));
@@ -127,7 +123,7 @@ void PropertyEditor::create(Viewer& parent)
 }
 
 void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::string& group,
-                                   ng::Widget* container, Viewer* viewer, bool editable)
+                                   ng::ref<ng::Widget> container, Viewer* viewer, bool editable)
 {
     const mx::UIProperties& ui = item.ui;
     mx::ValuePtr value = item.variable->getValue();
@@ -148,9 +144,9 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
 
     if (!group.empty())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
-        ng::Label* groupLabel = new ng::Label(twoColumns, group);
+        ng::ref<ng::Label> groupLabel = new ng::Label(twoColumns, group);
         groupLabel->set_font_size(20);
         groupLabel->set_font("sans-bold");
         new ng::Label(twoColumns, "");
@@ -187,11 +183,11 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
         const size_t valueIndex = indexInEnumeration();
         if (INVALID_INDEX != valueIndex)
         {
-            ng::Widget* twoColumns = new ng::Widget(container);
+            ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
             twoColumns->set_layout(_gridLayout2);
 
             new ng::Label(twoColumns, label);
-            ng::ComboBox* comboBox = new ng::ComboBox(twoColumns, { "" });
+            ng::ref<ng::ComboBox> comboBox = new ng::ComboBox(twoColumns, { "" });
             comboBox->set_enabled(editable);
             comboBox->set_items(enumeration);
             comboBox->set_selected_index(static_cast<int>(valueIndex));
@@ -215,7 +211,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
         }
         else
         {
-            ng::Widget* twoColumns = new ng::Widget(container);
+            ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
             twoColumns->set_layout(_gridLayout2);
 
             new ng::Label(twoColumns, label);
@@ -252,9 +248,9 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Float widget
     else if (value->isA<float>())
     {
-        ng::Widget* threeColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> threeColumns = new ng::Widget(container);
         threeColumns->set_layout(_gridLayout3);
-        ng::FloatBox<float>* floatBox = createFloatWidget(threeColumns, label, value->asA<float>(), &ui, [viewer, path](float value)
+        ng::ref<ng::FloatBox<float>> floatBox = createFloatWidget(threeColumns, label, value->asA<float>(), &ui, [viewer, path](float value)
         {
             mx::MaterialPtr material = viewer->getSelectedMaterial();
             if (material)
@@ -269,12 +265,12 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Boolean widget
     else if (value->isA<bool>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         bool v = value->asA<bool>();
         new ng::Label(twoColumns, label);
-        ng::CheckBox* boolVar = new ng::CheckBox(twoColumns, "");
+        ng::ref<ng::CheckBox> boolVar = new ng::CheckBox(twoColumns, "");
         boolVar->set_checked(v);
         boolVar->set_font_size(15);
         boolVar->set_callback([path, viewer](bool v)
@@ -290,7 +286,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Color3 input. Can map to a combo box if an enumeration
     else if (value->isA<mx::Color3>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         // Determine if there is an enumeration for this
@@ -312,7 +308,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
         // Create a combo box. The items are the enumerations in order.
         if (index >= 0)
         {
-            ng::ComboBox* comboBox = new ng::ComboBox(twoColumns, { "" });
+            ng::ref<ng::ComboBox> comboBox = new ng::ComboBox(twoColumns, { "" });
             comboBox->set_enabled(editable);
             comboBox->set_items(enumeration);
             comboBox->set_selected_index(index);
@@ -353,7 +349,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Color4 input
     else if (value->isA<mx::Color4>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         new ng::Label(twoColumns, label);
@@ -376,7 +372,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Vec 2 widget
     else if (value->isA<mx::Vector2>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         mx::Vector2 v = value->asA<mx::Vector2>();
@@ -415,7 +411,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Vec 3 input
     else if (value->isA<mx::Vector3>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         mx::Vector3 v = value->asA<mx::Vector3>();
@@ -470,7 +466,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
     // Vec 4 input
     else if (value->isA<mx::Vector4>())
     {
-        ng::Widget* twoColumns = new ng::Widget(container);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
         twoColumns->set_layout(_gridLayout2);
 
         mx::Vector4 v = value->asA<mx::Vector4>();
@@ -542,16 +538,17 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
         std::string v = value->asA<std::string>();
         if (!v.empty())
         {
-            ng::Widget* twoColumns = new ng::Widget(container);
+            ng::ref<ng::Widget> twoColumns = new ng::Widget(container);
             twoColumns->set_layout(_gridLayout2);
 
             if (item.variable->getType() == mx::Type::FILENAME)
             {
                 new ng::Label(twoColumns, label);
-                ng::Button* buttonVar = new ng::Button(twoColumns, mx::FilePath(v).getBaseName());
+                ng::ref<ng::Button> buttonVar = new ng::Button(twoColumns, mx::FilePath(v).getBaseName());
                 buttonVar->set_enabled(editable);
                 buttonVar->set_font_size(15);
-                buttonVar->set_callback([buttonVar, path, viewer]()
+                auto buttonVarPtr = buttonVar.get();
+                buttonVar->set_callback([buttonVarPtr, path, viewer]()
                 {
                     mx::MaterialPtr material = viewer->getSelectedMaterial();
                     mx::ShaderPort* uniform = material ? material->findUniform(path) : nullptr;
@@ -572,7 +569,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
                                 if (!filename.empty())
                                 {
                                     uniform->setValue(mx::Value::createValue<std::string>(filename));
-                                    buttonVar->set_caption(mx::FilePath(filename).getBaseName());
+                                    buttonVarPtr->set_caption(mx::FilePath(filename).getBaseName());
                                     viewer->perform_layout();
                                 }
                             }
@@ -583,7 +580,7 @@ void PropertyEditor::addItemToForm(const mx::UIPropertyItem& item, const std::st
             else
             {
                 new ng::Label(twoColumns, label);
-                ng::TextBox* stringVar = new ng::TextBox(twoColumns, v);
+                ng::ref<ng::TextBox> stringVar = new ng::TextBox(twoColumns, v);
                 stringVar->set_fixed_size({ 100, 20 });
                 stringVar->set_font_size(15);
                 stringVar->set_callback([path, viewer](const std::string& v)
@@ -629,14 +626,12 @@ void PropertyEditor::updateContents(Viewer* viewer)
         }
         if (!shaderName.empty() && shaderName != "surface")
         {
-            ng::Widget* twoColumns = new ng::Widget(_container);
+            ng::ref<ng::Widget> twoColumns = new ng::Widget(_container);
             twoColumns->set_layout(_gridLayout2);
-            ng::Widget* threeColumns = new ng::Widget(_container);
-            threeColumns->set_layout(_gridLayout3);
-            ng::Label* modelLabel = new ng::Label(twoColumns, "Shading Model");
+            ng::ref<ng::Label> modelLabel = new ng::Label(twoColumns, "Shading Model");
             modelLabel->set_font_size(20);
             modelLabel->set_font("sans-bold");
-            ng::Label* nameLabel = new ng::Label(twoColumns, shaderName);
+            ng::ref<ng::Label> nameLabel = new ng::Label(twoColumns, shaderName);
             nameLabel->set_font_size(20);
         }
     }
@@ -688,15 +683,15 @@ void PropertyEditor::updateContents(Viewer* viewer)
     viewer->perform_layout();
 }
 
-ng::FloatBox<float>* createFloatWidget(ng::Widget* parent, const std::string& label, float value,
-                                       const mx::UIProperties* ui, std::function<void(float)> callback)
+ng::ref<ng::FloatBox<float>> createFloatWidget(ng::ref<ng::Widget> parent, const std::string& label, float value,
+                                               const mx::UIProperties* ui, std::function<void(float)> callback)
 {
     new ng::Label(parent, label);
 
-    ng::Slider* slider = new ng::Slider(parent);
+    ng::ref<ng::Slider> slider = new ng::Slider(parent);
     slider->set_value(value);
 
-    ng::FloatBox<float>* box = new ng::FloatBox<float>(parent, value);
+    ng::ref<ng::FloatBox<float>> box = new ng::FloatBox<float>(parent, value);
     box->set_fixed_width(60);
     box->set_font_size(15);
     box->set_alignment(ng::TextBox::Alignment::Right);
@@ -734,29 +729,31 @@ ng::FloatBox<float>* createFloatWidget(ng::Widget* parent, const std::string& la
         }
     }
 
-    slider->set_callback([box, callback](float value)
+    auto sliderPtr = slider.get();
+    auto boxPtr = box.get();
+    slider->set_callback([boxPtr, callback](float value)
     {
-        box->set_value(value);
+        boxPtr->set_value(value);
         callback(value);
     });
-    box->set_callback([slider, callback](float value)
+    box->set_callback([sliderPtr, callback](float value)
     {
-        slider->set_value(value);
+        sliderPtr->set_value(value);
         callback(value);
     });
 
     return box;
 }
 
-ng::IntBox<int>* createIntWidget(ng::Widget* parent, const std::string& label, int value,
-                                 const mx::UIProperties* ui, std::function<void(int)> callback)
+ng::ref<ng::IntBox<int>> createIntWidget(ng::ref<ng::Widget> parent, const std::string& label, int value,
+                                         const mx::UIProperties* ui, std::function<void(int)> callback)
 {
     new ng::Label(parent, label);
 
-    ng::Slider* slider = new ng::Slider(parent);
+    ng::ref<ng::Slider> slider = new ng::Slider(parent);
     slider->set_value((float) value);
 
-    ng::IntBox<int>* box = new ng::IntBox<int>(parent, value);
+    ng::ref<ng::IntBox<int>> box = new ng::IntBox<int>(parent, value);
     box->set_fixed_width(60);
     box->set_font_size(15);
     box->set_alignment(ng::TextBox::Alignment::Right);
@@ -794,14 +791,16 @@ ng::IntBox<int>* createIntWidget(ng::Widget* parent, const std::string& label, i
         }
     }
 
-    slider->set_callback([box, callback](float value)
+    auto sliderPtr = slider.get();
+    auto boxPtr = box.get();
+    slider->set_callback([boxPtr, callback](float value)
     {
-        box->set_value((int) value);
+        boxPtr->set_value((int) value);
         callback((int) value);
     });
-    box->set_callback([slider, callback](int value)
+    box->set_callback([sliderPtr, callback](int value)
     {
-        slider->set_value((float) value);
+        sliderPtr->set_value((float) value);
         callback(value);
     });
 
diff --git a/source/MaterialXView/Editor.h b/source/MaterialXView/Editor.h
index b1fb4a3ade..b99f1f160c 100644
--- a/source/MaterialXView/Editor.h
+++ b/source/MaterialXView/Editor.h
@@ -39,7 +39,7 @@ class PropertyEditor
         }
     }
 
-    ng::Window* getWindow()
+    ng::ref<ng::Window> getWindow()
     {
         return _window;
     }
@@ -47,19 +47,19 @@ class PropertyEditor
   protected:
     void create(Viewer& parent);
     void addItemToForm(const mx::UIPropertyItem& item, const std::string& group,
-                       ng::Widget* container, Viewer* viewer, bool editable);
+                       ng::ref<ng::Widget> container, Viewer* viewer, bool editable);
 
-    ng::Window* _window;
-    ng::Widget* _container;
-    ng::GridLayout* _gridLayout2;
-    ng::GridLayout* _gridLayout3;
+    ng::ref<ng::Window> _window;
+    ng::ref<ng::Widget> _container;
+    ng::ref<ng::GridLayout> _gridLayout2;
+    ng::ref<ng::GridLayout> _gridLayout3;
     bool _visible;
     bool _fileDialogsForImages;
 };
 
-ng::FloatBox<float>* createFloatWidget(ng::Widget* parent, const std::string& label, float value,
-                                       const mx::UIProperties* ui, std::function<void(float)> callback = nullptr);
-ng::IntBox<int>* createIntWidget(ng::Widget* parent, const std::string& label, int value,
-                                 const mx::UIProperties* ui, std::function<void(int)> callback);
+ng::ref<ng::FloatBox<float>> createFloatWidget(ng::ref<ng::Widget> parent, const std::string& label, float value,
+                                               const mx::UIProperties* ui, std::function<void(float)> callback = nullptr);
+ng::ref<ng::IntBox<int>> createIntWidget(ng::ref<ng::Widget> parent, const std::string& label, int value,
+                                         const mx::UIProperties* ui, std::function<void(int)> callback);
 
 #endif // MATERIALXVIEW_EDITOR_H
diff --git a/source/MaterialXView/Viewer.cpp b/source/MaterialXView/Viewer.cpp
index c4c69bb812..46d03a1665 100644
--- a/source/MaterialXView/Viewer.cpp
+++ b/source/MaterialXView/Viewer.cpp
@@ -158,7 +158,6 @@ Viewer::Viewer(const std::string& materialFilename,
                const mx::Color3& screenColor) :
     ng::Screen(ng::Vector2i(screenWidth, screenHeight), "MaterialXView",
         true, false, true, true, USE_FLOAT_BUFFER, 4, 0),
-    _window(nullptr),
     _materialFilename(materialFilename),
     _meshFilename(meshFilename),
     _envRadianceFilename(envRadianceFilename),
@@ -184,11 +183,7 @@ Viewer::Viewer(const std::string& materialFilename,
     _shadowSoftness(1),
     _ambientOcclusionGain(0.6f),
     _selectedGeom(0),
-    _geomLabel(nullptr),
-    _geometrySelectionBox(nullptr),
     _selectedMaterial(0),
-    _materialLabel(nullptr),
-    _materialSelectionBox(nullptr),
     _identityCamera(mx::Camera::create()),
     _viewCamera(mx::Camera::create()),
     _envCamera(mx::Camera::create()),
@@ -232,9 +227,6 @@ Viewer::Viewer(const std::string& materialFilename,
     _bakeHeight(0),
     _bakeDocumentPerMaterial(false),
     _frameTiming(false),
-    _timingLabel(nullptr),
-    _timingPanel(nullptr),
-    _timingText(nullptr),
     _avgFrameTime(0.0)
 {
     // Resolve input filenames, taking both the provided search path and
@@ -295,11 +287,11 @@ void Viewer::initialize()
     _imageHandler->setSearchPath(_searchPath);
 
     // Initialize user interfaces.
-    createLoadMeshInterface(_window, "Load Mesh");
-    createLoadMaterialsInterface(_window, "Load Material");
-    createLoadEnvironmentInterface(_window, "Load Environment");
-    createPropertyEditorInterface(_window, "Property Editor");
-    createAdvancedSettings(_window);
+    createLoadMeshInterface((ng::ref<ng::Widget>) _window, "Load Mesh");
+    createLoadMaterialsInterface((ng::ref<ng::Widget>) _window, "Load Material");
+    createLoadEnvironmentInterface((ng::ref<ng::Widget>) _window, "Load Environment");
+    createPropertyEditorInterface((ng::ref<ng::Widget>) _window, "Property Editor");
+    createAdvancedSettings((ng::ref<ng::Widget>) _window);
 
     // Create geometry selection box.
     _geomLabel = new ng::Label(_window, "Select Geometry");
@@ -562,9 +554,9 @@ mx::ElementPredicate Viewer::getElementPredicate()
     };
 }
 
-void Viewer::createLoadMeshInterface(Widget* parent, const std::string& label)
+void Viewer::createLoadMeshInterface(ng::ref<Widget> parent, const std::string& label)
 {
-    ng::Button* meshButton = new ng::Button(parent, label);
+    ng::ref<ng::Button> meshButton = new ng::Button(parent, label);
     meshButton->set_icon(FA_FOLDER);
     meshButton->set_tooltip("Load a new geometry in the OBJ or glTF format.");
     meshButton->set_callback([this]()
@@ -590,9 +582,9 @@ void Viewer::createLoadMeshInterface(Widget* parent, const std::string& label)
     });
 }
 
-void Viewer::createLoadMaterialsInterface(Widget* parent, const std::string& label)
+void Viewer::createLoadMaterialsInterface(ng::ref<Widget> parent, const std::string& label)
 {
-    ng::Button* materialButton = new ng::Button(parent, label);
+    ng::ref<ng::Button> materialButton = new ng::Button(parent, label);
     materialButton->set_icon(FA_FOLDER);
     materialButton->set_tooltip("Load a material document in the MTLX format.");
     materialButton->set_callback([this]()
@@ -608,9 +600,9 @@ void Viewer::createLoadMaterialsInterface(Widget* parent, const std::string& lab
     });
 }
 
-void Viewer::createLoadEnvironmentInterface(Widget* parent, const std::string& label)
+void Viewer::createLoadEnvironmentInterface(ng::ref<Widget> parent, const std::string& label)
 {
-    ng::Button* envButton = new ng::Button(parent, label);
+    ng::ref<ng::Button> envButton = new ng::Button(parent, label);
     envButton->set_icon(FA_FOLDER);
     envButton->set_tooltip("Load a lat-long environment light in the HDR format.");
     envButton->set_callback([this]()
@@ -634,9 +626,9 @@ void Viewer::createLoadEnvironmentInterface(Widget* parent, const std::string& l
     });
 }
 
-void Viewer::createSaveMaterialsInterface(Widget* parent, const std::string& label)
+void Viewer::createSaveMaterialsInterface(ng::ref<Widget> parent, const std::string& label)
 {
-    ng::Button* materialButton = new ng::Button(parent, label);
+    ng::ref<ng::Button> materialButton = new ng::Button(parent, label);
     materialButton->set_icon(FA_SAVE);
     materialButton->set_tooltip("Save a material document in the MTLX format.");
     materialButton->set_callback([this]()
@@ -664,9 +656,9 @@ void Viewer::createSaveMaterialsInterface(Widget* parent, const std::string& lab
     });
 }
 
-void Viewer::createPropertyEditorInterface(Widget* parent, const std::string& label)
+void Viewer::createPropertyEditorInterface(ng::ref<Widget> parent, const std::string& label)
 {
-    ng::Button* editorButton = new ng::Button(parent, label);
+    ng::ref<ng::Button> editorButton = new ng::Button(parent, label);
     editorButton->set_flags(ng::Button::ToggleButton);
     editorButton->set_tooltip("View or edit properties of the current material.");
     editorButton->set_change_callback([this](bool state)
@@ -676,40 +668,38 @@ void Viewer::createPropertyEditorInterface(Widget* parent, const std::string& la
     });
 }
 
-void Viewer::createDocumentationInterface(Widget* parent, ng::VScrollPanel* scrollPanel)
+void Viewer::createDocumentationInterface(ng::ref<Widget> parent)
 {
-    ng::GridLayout* documentationLayout = new ng::GridLayout(ng::Orientation::Vertical, 3,
-                                                             ng::Alignment::Minimum, 13, 5);
+    ng::ref<ng::GridLayout> documentationLayout = new ng::GridLayout(ng::Orientation::Vertical, 3,
+                                                                     ng::Alignment::Minimum, 13, 5);
     documentationLayout->set_row_alignment({ ng::Alignment::Minimum, ng::Alignment::Maximum });
 
-    ng::Widget* documentationGroup = new ng::Widget(parent);
+    ng::ref<ng::Widget> documentationGroup = new ng::Widget(parent);
     documentationGroup->set_layout(documentationLayout);
-    ng::Label* documentationLabel = new ng::Label(documentationGroup, "Documentation");
+    ng::ref<ng::Label> documentationLabel = new ng::Label(documentationGroup, "Documentation");
     documentationLabel->set_font_size(20);
     documentationLabel->set_font("sans-bold");
 
-    ng::Button* shortcutsButton = new ng::Button(documentationGroup, "Keyboard Shortcuts");
-    shortcutsButton->set_flags(ng::Button::ToggleButton);
-    shortcutsButton->set_icon(FA_CARET_RIGHT);
-    shortcutsButton->set_fixed_width(230);
+    _shortcutsButton = new ng::Button(documentationGroup, "Keyboard Shortcuts");
+    _shortcutsButton->set_flags(ng::Button::ToggleButton);
+    _shortcutsButton->set_icon(FA_CARET_RIGHT);
+    _shortcutsButton->set_fixed_width(230);
 
-    ng::Widget* shortcutsTable = new ng::Widget(documentationGroup);
-    shortcutsTable->set_layout(new ng::GroupLayout(13));
-    shortcutsTable->set_visible(false);
+    _shortcutsTable = new ng::Widget(documentationGroup);
+    _shortcutsTable->set_layout(new ng::GroupLayout(13));
+    _shortcutsTable->set_visible(false);
 
-    // recompute layout when showing/hiding shortcuts.
-    shortcutsButton->set_change_callback([this, scrollPanel, shortcutsButton,
-                                          shortcutsTable](bool state)
+    // Recompute layout when showing/hiding shortcuts.
+    _shortcutsButton->set_change_callback([this](bool state)
     {
-        shortcutsTable->set_visible(state);
-        shortcutsButton->set_icon(state ? FA_CARET_DOWN : FA_CARET_RIGHT);
-        scrollPanel->set_scroll(state ? 0.73f : 1.0f);
+        _shortcutsButton->set_icon(state ? FA_CARET_DOWN : FA_CARET_RIGHT);
+        _shortcutsTable->set_visible(state);
         perform_layout();
     });
 
     // 2 cell layout for (key, description) pair.
-    ng::GridLayout* gridLayout2 = new ng::GridLayout(ng::Orientation::Horizontal, 2,
-                                                     ng::Alignment::Minimum, 2, 2);
+    ng::ref<ng::GridLayout> gridLayout2 = new ng::GridLayout(ng::Orientation::Horizontal, 2,
+                                                             ng::Alignment::Minimum, 2, 2);
     gridLayout2->set_col_alignment({ ng::Alignment::Minimum, ng::Alignment::Maximum });
 
     const std::vector<std::pair<std::string, std::string>> KEYBOARD_SHORTCUTS =
@@ -741,73 +731,73 @@ void Viewer::createDocumentationInterface(Widget* parent, ng::VScrollPanel* scro
 
     for (const auto& shortcut : KEYBOARD_SHORTCUTS)
     {
-        ng::Widget* twoColumns = new ng::Widget(shortcutsTable);
+        ng::ref<ng::Widget> twoColumns = new ng::Widget(_shortcutsTable);
         twoColumns->set_layout(gridLayout2);
 
-        ng::Label* keyLabel = new ng::Label(twoColumns, shortcut.first);
+        ng::ref<ng::Label> keyLabel = new ng::Label(twoColumns, shortcut.first);
         keyLabel->set_font("sans-bold");
         keyLabel->set_font_size(16);
         keyLabel->set_fixed_width(40);
 
-        ng::Label* descriptionLabel = new ng::Label(twoColumns, shortcut.second);
+        ng::ref<ng::Label> descriptionLabel = new ng::Label(twoColumns, shortcut.second);
         descriptionLabel->set_font_size(16);
         descriptionLabel->set_fixed_width(160);
     }
 }
 
-void Viewer::createAdvancedSettings(Widget* parent)
+void Viewer::createAdvancedSettings(ng::ref<Widget> parent)
 {
-    ng::PopupButton* advancedButton = new ng::PopupButton(parent, "Advanced Settings");
+    ng::ref<ng::PopupButton> advancedButton = new ng::PopupButton(parent, "Advanced Settings");
     advancedButton->set_icon(FA_TOOLS);
     advancedButton->set_chevron_icon(-1);
     advancedButton->set_tooltip("Asset and rendering options.");
-    ng::Popup* advancedPopupParent = advancedButton->popup();
+    ng::ref<ng::Popup> advancedPopupParent = advancedButton->popup();
     advancedPopupParent->set_layout(new ng::GroupLayout());
 
-    ng::VScrollPanel* scrollPanel = new ng::VScrollPanel(advancedPopupParent);
+    ng::ref<ng::VScrollPanel> scrollPanel = new ng::VScrollPanel(advancedPopupParent);
     scrollPanel->set_fixed_height(500);
-    ng::Widget* advancedPopup = new ng::Widget(scrollPanel);
+    ng::ref<ng::Widget> advancedPopup = new ng::Widget(scrollPanel);
     advancedPopup->set_layout(new ng::BoxLayout(ng::Orientation::Vertical));
 
-    ng::Widget* settingsGroup = new ng::Widget(advancedPopup);
+    ng::ref<ng::Widget> settingsGroup = new ng::Widget(advancedPopup);
     settingsGroup->set_layout(new ng::GroupLayout(13));
-    ng::Label* viewLabel = new ng::Label(settingsGroup, "Viewing Options");
+    ng::ref<ng::Label> viewLabel = new ng::Label(settingsGroup, "Viewing Options");
     viewLabel->set_font_size(20);
     viewLabel->set_font("sans-bold");
 
-    ng::CheckBox* drawEnvironmentBox = new ng::CheckBox(settingsGroup, "Draw Environment");
+    ng::ref<ng::CheckBox> drawEnvironmentBox = new ng::CheckBox(settingsGroup, "Draw Environment");
     drawEnvironmentBox->set_checked(_drawEnvironment);
     drawEnvironmentBox->set_callback([this](bool enable)
     {
         _drawEnvironment = enable;
     });
 
-    ng::CheckBox* outlineSelectedGeometryBox = new ng::CheckBox(settingsGroup, "Outline Selected Geometry");
+    ng::ref<ng::CheckBox> outlineSelectedGeometryBox = new ng::CheckBox(settingsGroup, "Outline Selected Geometry");
     outlineSelectedGeometryBox->set_checked(_outlineSelection);
     outlineSelectedGeometryBox->set_callback([this](bool enable)
     {
         _outlineSelection = enable;
     });
 
-    ng::Label* renderLabel = new ng::Label(settingsGroup, "Render Options");
+    ng::ref<ng::Label> renderLabel = new ng::Label(settingsGroup, "Render Options");
     renderLabel->set_font_size(20);
     renderLabel->set_font("sans-bold");
 
-    ng::CheckBox* transparencyBox = new ng::CheckBox(settingsGroup, "Render Transparency");
+    ng::ref<ng::CheckBox> transparencyBox = new ng::CheckBox(settingsGroup, "Render Transparency");
     transparencyBox->set_checked(_renderTransparency);
     transparencyBox->set_callback([this](bool enable)
     {
         _renderTransparency = enable;
     });
 
-    ng::CheckBox* doubleSidedBox = new ng::CheckBox(settingsGroup, "Render Double-Sided");
+    ng::ref<ng::CheckBox> doubleSidedBox = new ng::CheckBox(settingsGroup, "Render Double-Sided");
     doubleSidedBox->set_checked(_renderDoubleSided);
     doubleSidedBox->set_callback([this](bool enable)
     {
         _renderDoubleSided = enable;
     });
 
-    ng::CheckBox* importanceSampleBox = new ng::CheckBox(settingsGroup, "Environment FIS");
+    ng::ref<ng::CheckBox> importanceSampleBox = new ng::CheckBox(settingsGroup, "Environment FIS");
     importanceSampleBox->set_checked(_genContext.getOptions().hwSpecularEnvironmentMethod == mx::SPECULAR_ENVIRONMENT_FIS);
     _lightHandler->setUsePrefilteredMap(_genContext.getOptions().hwSpecularEnvironmentMethod != mx::SPECULAR_ENVIRONMENT_FIS);
     importanceSampleBox->set_callback([this](bool enable)
@@ -820,7 +810,7 @@ void Viewer::createAdvancedSettings(Widget* parent)
         reloadShaders();
     });
 
-    ng::CheckBox* refractionBox = new ng::CheckBox(settingsGroup, "Transmission Refraction");
+    ng::ref<ng::CheckBox> refractionBox = new ng::CheckBox(settingsGroup, "Transmission Refraction");
     refractionBox->set_checked(_genContext.getOptions().hwTransmissionRenderMethod == mx::TRANSMISSION_REFRACTION);
     refractionBox->set_callback([this](bool enable)
     {
@@ -831,14 +821,14 @@ void Viewer::createAdvancedSettings(Widget* parent)
         reloadShaders();
     });
 
-    ng::CheckBox* refractionSidedBox = new ng::CheckBox(settingsGroup, "Refraction Two-Sided");
+    ng::ref<ng::CheckBox> refractionSidedBox = new ng::CheckBox(settingsGroup, "Refraction Two-Sided");
     refractionSidedBox->set_checked(_lightHandler->getRefractionTwoSided());
     refractionSidedBox->set_callback([this](bool enable)
     {
         _lightHandler->setRefractionTwoSided(enable);
     });
 
-    ng::CheckBox* shaderInterfaceBox = new ng::CheckBox(settingsGroup, "Reduce Shader Interface");
+    ng::ref<ng::CheckBox> shaderInterfaceBox = new ng::CheckBox(settingsGroup, "Reduce Shader Interface");
     shaderInterfaceBox->set_checked(_genContext.getOptions().shaderInterfaceType == mx::SHADER_INTERFACE_REDUCED);
     shaderInterfaceBox->set_callback([this](bool enable)
     {
@@ -846,11 +836,11 @@ void Viewer::createAdvancedSettings(Widget* parent)
         setShaderInterfaceType(interfaceType);
     });
 
-    Widget* albedoGroup = new Widget(settingsGroup);
+    ng::ref<ng::Widget> albedoGroup = new Widget(settingsGroup);
     albedoGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     new ng::Label(albedoGroup, "Albedo Method:");
     mx::StringVec albedoOptions = { "Analytic", "Table", "MC" };
-    ng::ComboBox* albedoBox = new ng::ComboBox(albedoGroup, albedoOptions);
+    ng::ref<ng::ComboBox> albedoBox = new ng::ComboBox(albedoGroup, albedoOptions);
     albedoBox->set_chevron_icon(-1);
     albedoBox->set_selected_index((int) _genContext.getOptions().hwDirectionalAlbedoMethod );
     albedoBox->set_callback([this](int index)
@@ -877,7 +867,7 @@ void Viewer::createAdvancedSettings(Widget* parent)
         }
     });
 
-    Widget* sampleGroup = new Widget(settingsGroup);
+    ng::ref<ng::Widget> sampleGroup = new Widget(settingsGroup);
     sampleGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     new ng::Label(sampleGroup, "Environment Samples:");
     mx::StringVec sampleOptions;
@@ -887,7 +877,7 @@ void Viewer::createAdvancedSettings(Widget* parent)
         sampleOptions.push_back(std::to_string(i));
         m_process_events = true;
     }
-    ng::ComboBox* sampleBox = new ng::ComboBox(sampleGroup, sampleOptions);
+    ng::ref<ng::ComboBox> sampleBox = new ng::ComboBox(sampleGroup, sampleOptions);
     sampleBox->set_chevron_icon(-1);
     sampleBox->set_selected_index((int)std::log2(_lightHandler->getEnvSampleCount() / MIN_ENV_SAMPLE_COUNT) / 2);
     sampleBox->set_callback([this](int index)
@@ -895,30 +885,30 @@ void Viewer::createAdvancedSettings(Widget* parent)
         _lightHandler->setEnvSampleCount(MIN_ENV_SAMPLE_COUNT * (int) std::pow(4, index));
     });
 
-    ng::Label* lightingLabel = new ng::Label(settingsGroup, "Lighting Options");
+    ng::ref<ng::Label> lightingLabel = new ng::Label(settingsGroup, "Lighting Options");
     lightingLabel->set_font_size(20);
     lightingLabel->set_font("sans-bold");
 
-    ng::CheckBox* directLightingBox = new ng::CheckBox(settingsGroup, "Direct Lighting");
+    ng::ref<ng::CheckBox> directLightingBox = new ng::CheckBox(settingsGroup, "Direct Lighting");
     directLightingBox->set_checked(_lightHandler->getDirectLighting());
     directLightingBox->set_callback([this](bool enable)
     {
         _lightHandler->setDirectLighting(enable);
     });
 
-    ng::CheckBox* indirectLightingBox = new ng::CheckBox(settingsGroup, "Indirect Lighting");
+    ng::ref<ng::CheckBox> indirectLightingBox = new ng::CheckBox(settingsGroup, "Indirect Lighting");
     indirectLightingBox->set_checked(_lightHandler->getIndirectLighting());
     indirectLightingBox->set_callback([this](bool enable)
     {
         _lightHandler->setIndirectLighting(enable);
     });
 
-    ng::Widget* lightRotationRow = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> lightRotationRow = new ng::Widget(settingsGroup);
     lightRotationRow->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     mx::UIProperties ui;
     ui.uiMin = mx::Value::createValue(0.0f);
     ui.uiMax = mx::Value::createValue(360.0f);
-    ng::FloatBox<float>* lightRotationBox = createFloatWidget(lightRotationRow, "Light Rotation:",
+    ng::ref<ng::FloatBox<float>> lightRotationBox = createFloatWidget(lightRotationRow, "Light Rotation:",
         _lightRotation, &ui, [this](float value)
     {
         _lightRotation = value;
@@ -926,11 +916,11 @@ void Viewer::createAdvancedSettings(Widget* parent)
     });
     lightRotationBox->set_editable(true);
 
-    ng::Label* shadowingLabel = new ng::Label(settingsGroup, "Shadowing Options");
+    ng::ref<ng::Label> shadowingLabel = new ng::Label(settingsGroup, "Shadowing Options");
     shadowingLabel->set_font_size(20);
     shadowingLabel->set_font("sans-bold");
 
-    ng::CheckBox* shadowMapBox = new ng::CheckBox(settingsGroup, "Shadow Map");
+    ng::ref<ng::CheckBox> shadowMapBox = new ng::CheckBox(settingsGroup, "Shadow Map");
     shadowMapBox->set_checked(_genContext.getOptions().hwShadowMap);
     shadowMapBox->set_callback([this](bool enable)
     {
@@ -938,7 +928,7 @@ void Viewer::createAdvancedSettings(Widget* parent)
         reloadShaders();
     });
 
-    ng::CheckBox* ambientOcclusionBox = new ng::CheckBox(settingsGroup, "Ambient Occlusion");
+    ng::ref<ng::CheckBox> ambientOcclusionBox = new ng::CheckBox(settingsGroup, "Ambient Occlusion");
     ambientOcclusionBox->set_checked(_genContext.getOptions().hwAmbientOcclusion);
     ambientOcclusionBox->set_callback([this](bool enable)
     {
@@ -946,23 +936,23 @@ void Viewer::createAdvancedSettings(Widget* parent)
         reloadShaders();
     });
 
-    ng::Widget* ambientOcclusionGainRow = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> ambientOcclusionGainRow = new ng::Widget(settingsGroup);
     ambientOcclusionGainRow->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
-    ng::FloatBox<float>* ambientOcclusionGainBox = createFloatWidget(ambientOcclusionGainRow, "AO Gain:",
+    ng::ref<ng::FloatBox<float>> ambientOcclusionGainBox = createFloatWidget(ambientOcclusionGainRow, "AO Gain:",
         _ambientOcclusionGain, nullptr, [this](float value)
     {
         _ambientOcclusionGain = value;
     });
     ambientOcclusionGainBox->set_editable(true);
 
-    ng::Label* sceneLabel = new ng::Label(settingsGroup, "Scene Options");
+    ng::ref<ng::Label> sceneLabel = new ng::Label(settingsGroup, "Scene Options");
     sceneLabel->set_font_size(20);
     sceneLabel->set_font("sans-bold");
 
-    Widget* unitGroup = new Widget(settingsGroup);
+    ng::ref<Widget> unitGroup = new Widget(settingsGroup);
     unitGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     new ng::Label(unitGroup, "Distance Unit:");
-    ng::ComboBox* distanceUnitBox = new ng::ComboBox(unitGroup, _distanceUnitOptions);
+    ng::ref<ng::ComboBox> distanceUnitBox = new ng::ComboBox(unitGroup, _distanceUnitOptions);
     distanceUnitBox->set_fixed_size(ng::Vector2i(100, 20));
     distanceUnitBox->set_chevron_icon(-1);
     if (_distanceUnitConverter)
@@ -986,68 +976,68 @@ void Viewer::createAdvancedSettings(Widget* parent)
         m_process_events = true;
     });
 
-    ng::Label* meshLoading = new ng::Label(settingsGroup, "Mesh Loading Options");
+    ng::ref<ng::Label> meshLoading = new ng::Label(settingsGroup, "Mesh Loading Options");
     meshLoading->set_font_size(20);
     meshLoading->set_font("sans-bold");
 
-    ng::CheckBox* splitUdimsBox = new ng::CheckBox(settingsGroup, "Split By UDIMs");
+    ng::ref<ng::CheckBox> splitUdimsBox = new ng::CheckBox(settingsGroup, "Split By UDIMs");
     splitUdimsBox->set_checked(_splitByUdims);
     splitUdimsBox->set_callback([this](bool enable)
     {
         _splitByUdims = enable;
     });
 
-    ng::Label* materialLoading = new ng::Label(settingsGroup, "Material Loading Options");
+    ng::ref<ng::Label> materialLoading = new ng::Label(settingsGroup, "Material Loading Options");
     materialLoading->set_font_size(20);
     materialLoading->set_font("sans-bold");
 
-    ng::CheckBox* mergeMaterialsBox = new ng::CheckBox(settingsGroup, "Merge Materials");
+    ng::ref<ng::CheckBox> mergeMaterialsBox = new ng::CheckBox(settingsGroup, "Merge Materials");
     mergeMaterialsBox->set_checked(_mergeMaterials);
     mergeMaterialsBox->set_callback([this](bool enable)
     {
         _mergeMaterials = enable;
     });
 
-    ng::CheckBox* showInputsBox = new ng::CheckBox(settingsGroup, "Show All Inputs");
+    ng::ref<ng::CheckBox> showInputsBox = new ng::CheckBox(settingsGroup, "Show All Inputs");
     showInputsBox->set_checked(_showAllInputs);
     showInputsBox->set_callback([this](bool enable)
     {
         _showAllInputs = enable;
     });
 
-    ng::CheckBox* flattenBox = new ng::CheckBox(settingsGroup, "Flatten Subgraphs");
+    ng::ref<ng::CheckBox> flattenBox = new ng::CheckBox(settingsGroup, "Flatten Subgraphs");
     flattenBox->set_checked(_flattenSubgraphs);
     flattenBox->set_callback([this](bool enable)
     {
         _flattenSubgraphs = enable;
     });
 
-    ng::Label* envLoading = new ng::Label(settingsGroup, "Environment Loading Options");
+    ng::ref<ng::Label> envLoading = new ng::Label(settingsGroup, "Environment Loading Options");
     envLoading->set_font_size(20);
     envLoading->set_font("sans-bold");
 
-    ng::CheckBox* normalizeEnvBox = new ng::CheckBox(settingsGroup, "Normalize Environment");
+    ng::ref<ng::CheckBox> normalizeEnvBox = new ng::CheckBox(settingsGroup, "Normalize Environment");
     normalizeEnvBox->set_checked(_normalizeEnvironment);
     normalizeEnvBox->set_callback([this](bool enable)
     {
         _normalizeEnvironment = enable;
     });
 
-    ng::CheckBox* splitDirectLightBox = new ng::CheckBox(settingsGroup, "Split Direct Light");
+    ng::ref<ng::CheckBox> splitDirectLightBox = new ng::CheckBox(settingsGroup, "Split Direct Light");
     splitDirectLightBox->set_checked(_splitDirectLight);
     splitDirectLightBox->set_callback([this](bool enable)
     {
         _splitDirectLight = enable;
     });
 
-    ng::Label* translationLabel = new ng::Label(settingsGroup, "Translation Options (T)");
+    ng::ref<ng::Label> translationLabel = new ng::Label(settingsGroup, "Translation Options (T)");
     translationLabel->set_font_size(20);
     translationLabel->set_font("sans-bold");
 
-    ng::Widget* targetShaderGroup = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> targetShaderGroup = new ng::Widget(settingsGroup);
     targetShaderGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     new ng::Label(targetShaderGroup, "Target Shader");
-    ng::TextBox* targetShaderBox = new ng::TextBox(targetShaderGroup, _targetShader);
+    ng::ref<ng::TextBox> targetShaderBox = new ng::TextBox(targetShaderGroup, _targetShader);
     targetShaderBox->set_callback([this](const std::string& choice)
     {
         _targetShader = choice;
@@ -1056,46 +1046,46 @@ void Viewer::createAdvancedSettings(Widget* parent)
     targetShaderBox->set_font_size(16);
     targetShaderBox->set_editable(true);
 
-    ng::Label* textureLabel = new ng::Label(settingsGroup, "Texture Baking Options (B)");
+    ng::ref<ng::Label> textureLabel = new ng::Label(settingsGroup, "Texture Baking Options (B)");
     textureLabel->set_font_size(20);
     textureLabel->set_font("sans-bold");
 
-    ng::CheckBox* bakeHdrBox = new ng::CheckBox(settingsGroup, "Bake HDR Textures");
+    ng::ref<ng::CheckBox> bakeHdrBox = new ng::CheckBox(settingsGroup, "Bake HDR Textures");
     bakeHdrBox->set_checked(_bakeHdr);
     bakeHdrBox->set_callback([this](bool enable)
     {
         _bakeHdr = enable;
     });
 
-    ng::CheckBox* bakeAverageBox = new ng::CheckBox(settingsGroup, "Bake Averaged Textures");
+    ng::ref<ng::CheckBox> bakeAverageBox = new ng::CheckBox(settingsGroup, "Bake Averaged Textures");
     bakeAverageBox->set_checked(_bakeAverage);
     bakeAverageBox->set_callback([this](bool enable)
     {
         _bakeAverage = enable;
     });
 
-    ng::CheckBox* bakeOptimized = new ng::CheckBox(settingsGroup, "Optimize Baked Constants");
+    ng::ref<ng::CheckBox> bakeOptimized = new ng::CheckBox(settingsGroup, "Optimize Baked Constants");
     bakeOptimized->set_checked(_bakeOptimize);
     bakeOptimized->set_callback([this](bool enable)
     {
         _bakeOptimize = enable;
     });
 
-    ng::CheckBox* bakeDocumentPerMaterial= new ng::CheckBox(settingsGroup, "Bake Document Per Material");
+    ng::ref<ng::CheckBox> bakeDocumentPerMaterial= new ng::CheckBox(settingsGroup, "Bake Document Per Material");
     bakeDocumentPerMaterial->set_checked(_bakeDocumentPerMaterial);
     bakeDocumentPerMaterial->set_callback([this](bool enable)
     {
         _bakeDocumentPerMaterial = enable;
     });    
 
-    ng::Label* wedgeLabel = new ng::Label(settingsGroup, "Wedge Render Options (W)");
+    ng::ref<ng::Label> wedgeLabel = new ng::Label(settingsGroup, "Wedge Render Options (W)");
     wedgeLabel->set_font_size(20);
     wedgeLabel->set_font("sans-bold");
 
-    ng::Widget* wedgeNameGroup = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> wedgeNameGroup = new ng::Widget(settingsGroup);
     wedgeNameGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     new ng::Label(wedgeNameGroup, "Property Name");
-    ng::TextBox* wedgeNameBox = new ng::TextBox(wedgeNameGroup, _wedgePropertyName);
+    ng::ref<ng::TextBox> wedgeNameBox = new ng::TextBox(wedgeNameGroup, _wedgePropertyName);
     wedgeNameBox->set_callback([this](const std::string& choice)
     {
         _wedgePropertyName = choice;
@@ -1104,12 +1094,12 @@ void Viewer::createAdvancedSettings(Widget* parent)
     wedgeNameBox->set_font_size(16);
     wedgeNameBox->set_editable(true);
 
-    ng::Widget* wedgeMinGroup = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> wedgeMinGroup = new ng::Widget(settingsGroup);
     wedgeMinGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     mx::UIProperties wedgeProp;
     wedgeProp.uiSoftMin = mx::Value::createValue(0.0f);
     wedgeProp.uiSoftMax = mx::Value::createValue(1.0f);
-    ng::FloatBox<float>* wedgeMinBox = createFloatWidget(wedgeMinGroup, "Property Min:",
+    ng::ref<ng::FloatBox<float>> wedgeMinBox = createFloatWidget(wedgeMinGroup, "Property Min:",
         _wedgePropertyMax, &wedgeProp, [this](float value)
     {
         _wedgePropertyMin = value;
@@ -1117,9 +1107,9 @@ void Viewer::createAdvancedSettings(Widget* parent)
     wedgeMinBox->set_value(0.0);
     wedgeMinBox->set_editable(true);
 
-    ng::Widget* wedgeMaxGroup = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> wedgeMaxGroup = new ng::Widget(settingsGroup);
     wedgeMaxGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
-    ng::FloatBox<float>* wedgeMaxBox = createFloatWidget(wedgeMaxGroup, "Property Max:",
+    ng::ref<ng::FloatBox<float>> wedgeMaxBox = createFloatWidget(wedgeMaxGroup, "Property Max:",
         _wedgePropertyMax, &wedgeProp, [this](float value)
     {
         _wedgePropertyMax = value;
@@ -1127,13 +1117,13 @@ void Viewer::createAdvancedSettings(Widget* parent)
     wedgeMaxBox->set_value(1.0);
     wedgeMaxBox->set_editable(true);
 
-    ng::Widget* wedgeCountGroup = new ng::Widget(settingsGroup);
+    ng::ref<ng::Widget> wedgeCountGroup = new ng::Widget(settingsGroup);
     wedgeCountGroup->set_layout(new ng::BoxLayout(ng::Orientation::Horizontal));
     mx::UIProperties wedgeCountProp;
     wedgeCountProp.uiMin = mx::Value::createValue(1);
     wedgeCountProp.uiSoftMax = mx::Value::createValue(8);
     wedgeCountProp.uiStep = mx::Value::createValue(1);
-    ng::IntBox<int>* wedgeCountBox = createIntWidget(wedgeCountGroup, "Image Count:",
+    ng::ref<ng::IntBox<int>> wedgeCountBox = createIntWidget(wedgeCountGroup, "Image Count:",
         _wedgeImageCount, &wedgeCountProp, [this](int value)
     {
         _wedgeImageCount = value;
@@ -1141,7 +1131,7 @@ void Viewer::createAdvancedSettings(Widget* parent)
     wedgeCountBox->set_value(8);
     wedgeCountBox->set_editable(true);
 
-    createDocumentationInterface(advancedPopup, scrollPanel);
+    createDocumentationInterface(advancedPopup);
 }
 
 void Viewer::updateGeometrySelections()
@@ -2441,7 +2431,7 @@ void Viewer::updateCameras()
 void Viewer::updateDisplayedProperties()
 {
     _propertyEditor.updateContents(this);
-    createSaveMaterialsInterface(_propertyEditor.getWindow(), "Save Material");
+    createSaveMaterialsInterface((ng::ref<ng::Widget>) _propertyEditor.getWindow(), "Save Material");
     perform_layout();
 }
 
diff --git a/source/MaterialXView/Viewer.h b/source/MaterialXView/Viewer.h
index 08712f3c78..8f0257e1e1 100644
--- a/source/MaterialXView/Viewer.h
+++ b/source/MaterialXView/Viewer.h
@@ -179,7 +179,7 @@ class Viewer : public ng::Screen
     }
 
     // Return the underlying NanoGUI window.
-    ng::Window* getWindow() const
+    ng::ref<ng::Window> getWindow() const
     {
         return _window;
     }
@@ -283,13 +283,13 @@ class Viewer : public ng::Screen
     void updateMaterialSelectionUI();
     void updateDisplayedProperties();
 
-    void createLoadMeshInterface(Widget* parent, const std::string& label);
-    void createLoadMaterialsInterface(Widget* parent, const std::string& label);
-    void createLoadEnvironmentInterface(Widget* parent, const std::string& label);
-    void createSaveMaterialsInterface(Widget* parent, const std::string& label);
-    void createPropertyEditorInterface(Widget* parent, const std::string& label);
-    void createAdvancedSettings(Widget* parent);
-    void createDocumentationInterface(Widget* parent, ng::VScrollPanel* scrollPanel);
+    void createLoadMeshInterface(ng::ref<Widget> parent, const std::string& label);
+    void createLoadMaterialsInterface(ng::ref<Widget> parent, const std::string& label);
+    void createLoadEnvironmentInterface(ng::ref<Widget> parent, const std::string& label);
+    void createSaveMaterialsInterface(ng::ref<Widget> parent, const std::string& label);
+    void createPropertyEditorInterface(ng::ref<Widget> parent, const std::string& label);
+    void createAdvancedSettings(ng::ref<Widget> parent);
+    void createDocumentationInterface(ng::ref<Widget> parent);
 
     // Return the ambient occlusion image, if any, associated with the given material.
     mx::ImagePtr getAmbientOcclusionImage(mx::MaterialPtr material);
@@ -318,7 +318,7 @@ class Viewer : public ng::Screen
     void setShaderInterfaceType(mx::ShaderInterfaceType interfaceType);
 
   private:
-    ng::Window* _window;
+    ng::ref<ng::Window> _window;
     RenderPipelinePtr _renderPipeline;
 
     mx::FilePath _materialFilename;
@@ -380,15 +380,15 @@ class Viewer : public ng::Screen
     // Geometry selections
     std::vector<mx::MeshPartitionPtr> _geometryList;
     size_t _selectedGeom;
-    ng::Label* _geomLabel;
-    ng::ComboBox* _geometrySelectionBox;
+    ng::ref<ng::Label> _geomLabel;
+    ng::ref<ng::ComboBox> _geometrySelectionBox;
 
     // Material selections
     std::vector<mx::MaterialPtr> _materials;
     mx::MaterialPtr _wireMaterial;
     size_t _selectedMaterial;
-    ng::Label* _materialLabel;
-    ng::ComboBox* _materialSelectionBox;
+    ng::ref<ng::Label> _materialLabel;
+    ng::ref<ng::ComboBox> _materialSelectionBox;
     PropertyEditor _propertyEditor;
 
     // Material assignments
@@ -475,11 +475,15 @@ class Viewer : public ng::Screen
 
     // Frame timing
     bool _frameTiming;
-    ng::Label* _timingLabel;
-    ng::Widget* _timingPanel;
-    ng::TextBox* _timingText;
+    ng::ref<ng::Label> _timingLabel;
+    ng::ref<ng::Widget> _timingPanel;
+    ng::ref<ng::TextBox> _timingText;
     mx::ScopedTimer _frameTimer;
     double _avgFrameTime;
+
+    // Documentation UI
+    ng::ref<ng::Button> _shortcutsButton;
+    ng::ref<ng::Widget> _shortcutsTable;
 };
 
 extern const mx::Vector3 DEFAULT_CAMERA_POSITION;