diff --git a/apps/sample-gui/CMakeLists.txt b/apps/sample-gui/CMakeLists.txt
index 7190117..8692893 100644
--- a/apps/sample-gui/CMakeLists.txt
+++ b/apps/sample-gui/CMakeLists.txt
@@ -7,6 +7,8 @@ list(APPEND client_HEADERS
     audio_editor/AudioEditorView.h
     image_editor/ImageEditorView.h
     image_editor/ImageViewWidget.h
+    canvas/CanvasView.h
+    canvas/CanvasController.h
     web_client/WebClientView.h)
 
 
@@ -18,6 +20,8 @@ list(APPEND client_LIB_INCLUDES
     audio_editor/AudioEditorView.cpp
     image_editor/ImageEditorView.cpp
     image_editor/ImageViewWidget.cpp
+    canvas/CanvasView.cpp
+    canvas/CanvasController.cpp
     web_client/WebClientView.cpp
     MediaTool.cpp)
    
@@ -37,6 +41,7 @@ target_include_directories(sample_gui PUBLIC
     "${CMAKE_CURRENT_SOURCE_DIR}/audio_editor"
     "${CMAKE_CURRENT_SOURCE_DIR}/image_editor"
     "${CMAKE_CURRENT_SOURCE_DIR}/web_client"
+    "${CMAKE_CURRENT_SOURCE_DIR}/canvas"
                               )
 target_link_libraries(sample_gui PUBLIC client windows console core network database geometry audio web)
 set_property(TARGET sample_gui PROPERTY FOLDER apps)
diff --git a/apps/sample-gui/MediaTool.cpp b/apps/sample-gui/MediaTool.cpp
index 2f83e4c..7f377a5 100644
--- a/apps/sample-gui/MediaTool.cpp
+++ b/apps/sample-gui/MediaTool.cpp
@@ -4,6 +4,8 @@
 #include "AudioEditorView.h"
 #include "ImageEditorView.h"
 #include "WebClientView.h"
+#include "CanvasView.h"
+
 #include "TabbedPanelWidget.h"
 #include "TopBar.h"
 #include "TextNode.h"
@@ -31,9 +33,9 @@ void MediaTool::initializeViews()
     auto path = mMainApplication->getCommandLineArgs()->getLaunchPath();
     path /= "out.txt";
     textEditor->setName("TextEditor");
-    textEditor->GetController()->SetSavePath(path);
-    textEditor->GetController()->SetLoadPath(path);
-    textEditor->Initialize();
+    textEditor->getController()->SetSavePath(path);
+    textEditor->getController()->SetLoadPath(path);
+    textEditor->initialize();
     tabbedPanel->addPanel(std::move(textEditor), "Text Editor");
 
     auto audioEditor = AudioEditorView::Create();
@@ -48,6 +50,10 @@ void MediaTool::initializeViews()
     webClient->setName("webClient");
     tabbedPanel->addPanel(std::move(webClient), "Web Client");
 
+    auto canvas = CanvasView::Create();
+    canvas->setName("CanvasView");
+    tabbedPanel->addPanel(std::move(canvas), "Canvas");
+
     auto topBar = TopBar::Create();
     auto statusBar = StatusBar::Create();
 
diff --git a/apps/sample-gui/canvas/CanvasController.cpp b/apps/sample-gui/canvas/CanvasController.cpp
new file mode 100644
index 0000000..83829d3
--- /dev/null
+++ b/apps/sample-gui/canvas/CanvasController.cpp
@@ -0,0 +1,6 @@
+#include "CanvasController.h"
+
+std::unique_ptr<CanvasController> CanvasController::Create()
+{
+    return std::make_unique<CanvasController>();
+}
diff --git a/apps/sample-gui/canvas/CanvasController.h b/apps/sample-gui/canvas/CanvasController.h
new file mode 100644
index 0000000..9d56ec5
--- /dev/null
+++ b/apps/sample-gui/canvas/CanvasController.h
@@ -0,0 +1,9 @@
+#pragma once
+
+#include <memory>
+
+class CanvasController
+{
+public:
+    static std::unique_ptr<CanvasController> Create();
+};
diff --git a/apps/sample-gui/canvas/CanvasView.cpp b/apps/sample-gui/canvas/CanvasView.cpp
new file mode 100644
index 0000000..c8fbc6e
--- /dev/null
+++ b/apps/sample-gui/canvas/CanvasView.cpp
@@ -0,0 +1,75 @@
+#include "CanvasView.h"
+
+#include "HorizontalSpacer.h"
+#include "VerticalSpacer.h"
+
+#include "CanvasController.h"
+
+#include "Theme.h"
+
+#include "TextNode.h"
+#include "Label.h"
+#include "Button.h"
+
+#include <iostream>
+
+CanvasView::CanvasView()
+      : mController(CanvasController::Create())
+{
+    initialize();
+}
+
+CanvasView::~CanvasView()
+{
+
+}
+
+std::unique_ptr<CanvasView> CanvasView::Create()
+{
+    return std::make_unique<CanvasView>();
+}
+
+void CanvasView::initialize()
+{
+    auto label = Label::Create();
+    label->setLabel("Canvas");
+    label->setBackgroundColor(Theme::getBannerBackground());
+    label->setMargin(1);
+
+
+
+    auto hSpacer = HorizontalSpacer::Create();
+    hSpacer->addWidgetWithScale(std::move(label), 1);
+    //hSpacer->addWidgetWithScale(std::move(textBox), 14);
+
+    auto cache_button_spacer = initializeCacheButtons();
+    hSpacer->addWidgetWithScale(std::move(cache_button_spacer), 1);
+
+    addWidget(std::move(hSpacer));
+}
+
+std::unique_ptr<Widget> CanvasView::initializeCacheButtons()
+{
+    auto saveButton = Button::Create();
+    saveButton->setLabel("Save");
+    saveButton->setBackgroundColor(Theme::getButtonPrimaryBackground());
+    saveButton->setMargin(2);
+
+    auto clearButton = Button::Create();
+    clearButton->setLabel("Clear");
+    clearButton->setBackgroundColor(Theme::getButtonPrimaryBackground());
+    clearButton->setMargin(2);
+
+    auto loadButton = Button::Create();
+    loadButton->setLabel("Load");
+    loadButton->setBackgroundColor(Theme::getButtonPrimaryBackground());
+    loadButton->setMargin(2);
+
+    auto buttonSpacer = VerticalSpacer::Create();
+    buttonSpacer->AddWidgetWithScale(std::move(saveButton), 1);
+    buttonSpacer->AddWidgetWithScale(std::move(clearButton), 1);
+    buttonSpacer->AddWidgetWithScale(std::move(loadButton), 1);
+
+    return buttonSpacer;
+}
+
diff --git a/apps/sample-gui/canvas/CanvasView.h b/apps/sample-gui/canvas/CanvasView.h
new file mode 100644
index 0000000..ddc4c3e
--- /dev/null
+++ b/apps/sample-gui/canvas/CanvasView.h
@@ -0,0 +1,26 @@
+#pragma once
+
+#include "Widget.h"
+
+class CanvasController;
+
+class CanvasView : public Widget
+{
+public:
+    CanvasView();
+
+    ~CanvasView();
+
+    static std::unique_ptr<CanvasView> Create();
+
+private:
+
+    void initialize();
+
+    std::unique_ptr<Widget> initializeCacheButtons();
+
+    //std::unique_ptr<Widget> initializeCacheButtons();
+
+    std::unique_ptr<CanvasController> mController;
+};
+using CanvasViewPtr = std::unique_ptr<CanvasView>;
diff --git a/apps/sample-gui/text_editor/TextEditorController.h b/apps/sample-gui/text_editor/TextEditorController.h
index 2a62067..37d717d 100644
--- a/apps/sample-gui/text_editor/TextEditorController.h
+++ b/apps/sample-gui/text_editor/TextEditorController.h
@@ -5,10 +5,6 @@
 
 class TextEditorController
 {
-    TextEditorModelUPtr mModel;
-    std::filesystem::path mSavePath;
-    std::filesystem::path mLoadPath;
-
 public:
 
     TextEditorController();
@@ -28,6 +24,11 @@ public:
     void SetSavePath(const std::filesystem::path& path);
 
     void SetLoadPath(const std::filesystem::path& path);
+
+private:
+    TextEditorModelUPtr mModel;
+    std::filesystem::path mSavePath;
+    std::filesystem::path mLoadPath;
 };
 
 using TextEditorControllerUPtr = std::unique_ptr<TextEditorController>;
diff --git a/apps/sample-gui/text_editor/TextEditorView.cpp b/apps/sample-gui/text_editor/TextEditorView.cpp
index b557819..26e322c 100644
--- a/apps/sample-gui/text_editor/TextEditorView.cpp
+++ b/apps/sample-gui/text_editor/TextEditorView.cpp
@@ -16,12 +16,12 @@ TextEditorView::TextEditorView()
 
 }
 
-TextEditorController* TextEditorView::GetController()
+TextEditorController* TextEditorView::getController()
 {
     return mController.get();
 }
 
-void TextEditorView::Initialize()
+void TextEditorView::initialize()
 {
     auto label = Label::Create();
     label->setLabel("Text Editor");
diff --git a/apps/sample-gui/text_editor/TextEditorView.h b/apps/sample-gui/text_editor/TextEditorView.h
index 68d80ae..57aae3d 100644
--- a/apps/sample-gui/text_editor/TextEditorView.h
+++ b/apps/sample-gui/text_editor/TextEditorView.h
@@ -5,21 +5,23 @@
 #include "Label.h"
 #include "TextBox.h"
 #include "TextEditorController.h"
+
 #include <functional>
 
 class TextEditorView : public Widget
 {
-    TextBox* mTextBox;
-    TextEditorControllerUPtr mController;
-
 public:
 
     TextEditorView();
 
     static std::unique_ptr<TextEditorView> Create();
 
-    TextEditorController* GetController();
+    TextEditorController* getController();
 
-    void Initialize();
+    void initialize();
+
+private:
+    TextBox* mTextBox;
+    TextEditorControllerUPtr mController;
 };
 using TextEditorViewUPtr = std::unique_ptr<TextEditorView>;
diff --git a/src/mesh/AbstractFace.cpp b/src/mesh/AbstractFace.cpp
index c41a394..c3f51c4 100644
--- a/src/mesh/AbstractFace.cpp
+++ b/src/mesh/AbstractFace.cpp
@@ -1,11 +1,18 @@
 #include "AbstractFace.h"
 
+#include "Edge.h"
+
 AbstractFace::AbstractFace(unsigned id)
     : mId(id)
 {
 
 }
 
+AbstractFace::~AbstractFace()
+{
+
+}
+
 void AbstractFace::addVectorAttribute(const std::string& tag, const std::vector<double>& values)
 {
     mVectorAttributes[tag] = values;
@@ -20,3 +27,8 @@ std::vector<double> AbstractFace::getVectorAttribute(const std::string& tag) con
     }
     return {};
 }
+
+void AbstractFace::setIndex(std::size_t idx)
+{
+    mId = idx;
+}
diff --git a/src/mesh/AbstractFace.h b/src/mesh/AbstractFace.h
index 5c4649d..511d457 100644
--- a/src/mesh/AbstractFace.h
+++ b/src/mesh/AbstractFace.h
@@ -5,12 +5,14 @@
 #include <unordered_map>
 #include <string>
 
+class Edge;
+
 class AbstractFace
 {
 public:
     AbstractFace(unsigned id=0);
 
-    virtual ~AbstractFace() = default;
+    virtual ~AbstractFace();
 
     virtual std::vector<unsigned> getNodeIds() const = 0;
 
@@ -18,6 +20,16 @@ public:
 
     std::vector<double> getVectorAttribute(const std::string& tag) const;
 
+    void setIndex(std::size_t idx);
+
+    virtual unsigned getNumNodes() const = 0;
+
+    virtual void associateWidthEdges() = 0;
+
+    virtual void replaceEdge(Edge* original, Edge* replacement) = 0;
+
+    virtual std::vector<unsigned> getEdgeIds() const = 0;
+
 protected:
     unsigned mId{0};
     std::unordered_map<std::string, std::vector<double> > mVectorAttributes;
diff --git a/src/mesh/AbstractMesh.h b/src/mesh/AbstractMesh.h
index 6acfe90..975f55d 100644
--- a/src/mesh/AbstractMesh.h
+++ b/src/mesh/AbstractMesh.h
@@ -40,6 +40,8 @@ public:
         return ret;
     }
 
+    virtual std::unique_ptr<AbstractMesh> copy() const = 0;
+
     std::vector<std::vector<double> > getNodeVectorAttributes(const std::string& tag);
 
     std::vector<double> getVectorAttribute(const std::string& tag) const;
diff --git a/src/mesh/CMakeLists.txt b/src/mesh/CMakeLists.txt
index e1b239b..f654d47 100644
--- a/src/mesh/CMakeLists.txt
+++ b/src/mesh/CMakeLists.txt
@@ -7,6 +7,7 @@ list(APPEND mesh_LIB_INCLUDES
         Node.cpp
         QuadMesh.cpp
         TriMesh.cpp
+        FaceMesh.cpp
         LineMesh.cpp
         MeshPrimitives.cpp
         MeshBuilder.cpp)
diff --git a/src/mesh/Edge.cpp b/src/mesh/Edge.cpp
index 35d8dec..5fc6137 100644
--- a/src/mesh/Edge.cpp
+++ b/src/mesh/Edge.cpp
@@ -28,3 +28,95 @@ unsigned Edge::getNode1Id() const
 {
     return mNode1->getIndex();
 }
+
+bool Edge::isOverlapping(Edge* edge) const
+{
+    auto overlaps = edge->getNode0()->isCoincident(mNode0) && edge->getNode1()->isCoincident(mNode1);
+    if (overlaps)
+    {
+        return true;
+    }
+    else
+    {
+        return edge->getNode1()->isCoincident(mNode0) && edge->getNode0()->isCoincident(mNode1);
+    }
+}
+
+bool Edge::hasSameNodes(Edge* edge) const
+{
+    return edge->getNode0() == edge->getNode1() || edge->getNode1() == edge->getNode0();
+}
+
+void Edge::replaceNodes(Node* node0, Node* node1)
+{
+    mNode0 = node0;
+    mNode1 = node1;
+}
+
+Node* Edge::getNode0() const
+{
+    return mNode0;
+}
+
+Node* Edge::getNode1() const
+{
+    return mNode1;
+}
+
+Node* Edge::getOtherNode(Node* node) const
+{
+    if (node == mNode0)
+    {
+        return mNode1;
+    }
+    else
+    {
+        return mNode0;
+    }
+}
+
+unsigned Edge::getId() const
+{
+    return mId;
+}
+
+void Edge::setState(State state)
+{
+    mState = state;
+}
+
+Edge::State Edge::getState() const
+{
+    return mState;
+}
+
+void Edge::clearConnectivity()
+{
+    mAssociatedFaceIds.clear();
+}
+
+unsigned Edge::getNumConnectedFaces() const
+{
+    return mAssociatedFaceIds.size();
+}
+
+void Edge::associateFace(unsigned faceId)
+{
+    mAssociatedFaceIds.push_back(faceId);
+}
+
+unsigned Edge::getConnectedFaceId(std::size_t idx) const
+{
+    return mAssociatedFaceIds[idx];
+}
+
+void Edge::associateWithNodes()
+{
+    mNode0->associateEdge(mId);
+    mNode1->associateEdge(mId);
+}
+
+void Edge::setIndex(unsigned idx)
+{
+    mId = idx;
+}
diff --git a/src/mesh/Edge.h b/src/mesh/Edge.h
index 6e73af9..83d7d9d 100644
--- a/src/mesh/Edge.h
+++ b/src/mesh/Edge.h
@@ -1,23 +1,65 @@
 #pragma once
 
-class Node;
-
 #include <memory>
+#include <vector>
+
+class Node;
 
 class Edge
 {
 public:
+    enum class State
+    {
+        HEALTHY,
+        DIRTY
+    };
+
     Edge(Node* node0, Node* node1, unsigned id = 0);
+
     ~Edge();
 
     static std::unique_ptr<Edge> Create(Node* node0, Node* node1, unsigned id = 0);
 
+    void associateFace(unsigned faceId);
+
+    void associateWithNodes();
+
+    void clearConnectivity();
+
+    unsigned getConnectedFaceId(std::size_t idx) const;
+
+    State getState() const;
+
+    unsigned getId() const;
+
     unsigned getNode0Id() const;
 
     unsigned getNode1Id() const;
 
+    Node* getNode0() const;
+
+    Node* getNode1() const;
+
+    unsigned getNumConnectedFaces() const;
+
+    Node* getOtherNode(Node* node) const;
+
+    bool isOverlapping(Edge* edge) const;
+
+    bool hasSameNodes(Edge* edge) const;
+
+    void replaceNodes(Node* node0, Node* node1);
+
+    void setState(State state);
+
+    void setIndex(unsigned idx);
+
 private:
     unsigned mId{0};
     Node* mNode0{nullptr};
     Node* mNode1{nullptr};
+
+    std::vector<unsigned> mAssociatedFaceIds;
+
+    State mState{State::HEALTHY};
 };
diff --git a/src/mesh/FaceMesh.cpp b/src/mesh/FaceMesh.cpp
new file mode 100644
index 0000000..b08b77e
--- /dev/null
+++ b/src/mesh/FaceMesh.cpp
@@ -0,0 +1,182 @@
+#include "FaceMesh.h"
+
+#include "Node.h"
+#include "Edge.h"
+#include "AbstractFace.h"
+
+FaceMesh::~FaceMesh()
+{
+
+}
+
+void FaceMesh::populate(VecNodes& nodes, VecEdges& edges, VecFaces& faces)
+{
+    mNodes = std::move(nodes);
+    mEdges = std::move(edges);
+    mFaces = std::move(faces);
+
+    resetIds();
+    resetConnectivity();
+}
+
+std::vector<unsigned> FaceMesh::getFaceNodeIds() const
+{
+    if (mFaces.empty())
+    {
+        return {};
+    }
+
+    auto nodes_per_face = mFaces[0]->getNumNodes();
+    std::vector<unsigned> ids(nodes_per_face*mFaces.size());
+
+    for(std::size_t idx=0; idx<mFaces.size(); idx++)
+    {
+        const auto nodeIds = mFaces[idx]->getNodeIds();
+        for(std::size_t jdx=0; jdx<nodes_per_face; jdx++)
+        {
+            ids[nodes_per_face*idx + jdx] = nodeIds[jdx];
+        }
+    }
+    return ids;
+}
+
+std::vector<std::vector<double> > FaceMesh::getFaceVectorAttributes(const std::string& tag)
+{
+    std::vector<std::vector<double> > attribs(mFaces.size());
+    for(std::size_t idx=0; idx<mFaces.size(); idx++)
+    {
+        attribs[idx] = {mFaces[idx]->getVectorAttribute(tag)};
+    }
+    return attribs;
+}
+
+void FaceMesh::addConstantFaceVectorAttribute(const std::string& tag, const std::vector<double>& values)
+{
+    for (const auto& face : mFaces)
+    {
+        face->addVectorAttribute(tag, values);
+    }
+}
+
+void FaceMesh::resetIds()
+{
+    unsigned count = 0;
+    for (auto& node : mNodes)
+    {
+        node->setIndex(count);
+    }
+
+    count = 0;
+    for (auto& edge : mEdges)
+    {
+        edge->setIndex(count);
+    }
+
+    count = 0;
+    for (auto& face : mFaces)
+    {
+        face->setIndex(count);
+    }
+}
+
+void FaceMesh::resetConnectivity()
+{
+    for (auto& node : mNodes)
+    {
+        node->clearConnectivity();
+    }
+
+    for (auto& edge : mEdges)
+    {
+        edge->associateWithNodes();
+        edge->clearConnectivity();
+    }
+
+    for (auto& face : mFaces)
+    {
+        face->associateWidthEdges();
+    }
+}
+
+void FaceMesh::replaceIfOverlapping(FaceMesh* mesh, Node* target_node) const
+{
+    for (auto& node : mNodes)
+    {
+        if (node->getNumConnectedEdges() == 3 && node->isCoincident(target_node))
+        {
+            target_node->setState(Node::State::DIRTY);
+            for (unsigned idx=0; idx<3; idx++)
+            {
+                auto edge = mesh->mEdges[idx].get();
+                edge->replaceNodes(target_node, node.get());
+            }
+            break;
+        }
+    }
+}
+
+void FaceMesh::replaceIfOverlapping(FaceMesh* mesh, Edge* target_edge) const
+{
+    for (auto& edge : mEdges)
+    {
+        if (edge->getNumConnectedFaces() == 2 && target_edge->hasSameNodes(edge.get()))
+        {
+            target_edge->setState(Edge::State::DIRTY);
+            for (unsigned idx=0; idx<2; idx++)
+            {
+                auto face = mesh->mFaces[idx].get();
+                face->replaceEdge(target_edge, edge.get());
+            }
+            break;
+        }
+    }
+}
+
+void FaceMesh::merge(std::unique_ptr<FaceMesh> mesh)
+{
+    if (mesh->getType() != getType())
+    {
+        return;
+    }
+
+    for (auto& node : mesh->mNodes)
+    {
+        if (node->getNumConnectedEdges() == 3)
+        {
+            replaceIfOverlapping(mesh.get(), node.get());
+        }
+    }
+
+    for (auto& node : mesh->mNodes)
+    {
+        if (node->getState() == Node::State::HEALTHY)
+        {
+            mNodes.push_back(std::move(node));
+        }
+    }
+
+    for (auto& edge : mesh->mEdges)
+    {
+        if (edge->getNumConnectedFaces() == 2)
+        {
+            replaceIfOverlapping(mesh.get(), edge.get());
+        }
+    }
+
+    for (auto& edge : mesh->mEdges)
+    {
+        if (edge->getState() == Edge::State::HEALTHY)
+        {
+            mEdges.push_back(std::move(edge));
+        }
+    }
+
+    for (auto& face : mesh->mFaces)
+    {
+        mFaces.push_back(std::move(face));
+    }
+
+    mesh.reset();
+    resetIds();
+    resetConnectivity();
+}
diff --git a/src/mesh/FaceMesh.h b/src/mesh/FaceMesh.h
new file mode 100644
index 0000000..2596115
--- /dev/null
+++ b/src/mesh/FaceMesh.h
@@ -0,0 +1,47 @@
+#pragma once
+
+#include "AbstractMesh.h"
+
+#include <string>
+#include <unordered_map>
+
+class Edge;
+class AbstractFace;
+
+using EdgePtr = std::unique_ptr<Edge>;
+using AbstractFacePtr = std::unique_ptr<AbstractFace>;
+
+using VecEdges = std::vector<EdgePtr>;
+using VecFaces = std::vector<AbstractFacePtr>;
+
+class FaceMesh : public AbstractMesh
+{
+public:
+    FaceMesh() = default;
+
+    ~FaceMesh();
+
+    virtual std::unique_ptr<AbstractMesh> copy() const = 0;
+
+    void populate(VecNodes& nodes, VecEdges& edges, VecFaces& faces);
+
+    std::vector<unsigned> getFaceNodeIds() const;
+
+    void addConstantFaceVectorAttribute(const std::string& tag, const std::vector<double>& values);
+
+    std::vector<std::vector<double> > getFaceVectorAttributes(const std::string& tag);
+
+    void merge(std::unique_ptr<FaceMesh> mesh);
+
+protected:
+    void resetConnectivity();
+
+    void resetIds();
+
+    void replaceIfOverlapping(FaceMesh* mesh, Node* node) const;
+
+    void replaceIfOverlapping(FaceMesh* mesh, Edge* edge) const;
+
+    VecEdges mEdges;
+    VecFaces mFaces;
+};
diff --git a/src/mesh/LineMesh.cpp b/src/mesh/LineMesh.cpp
index 3823244..4a864de 100644
--- a/src/mesh/LineMesh.cpp
+++ b/src/mesh/LineMesh.cpp
@@ -13,6 +13,16 @@ void LineMesh::populate(VecNodes& nodes, VecEdges& edges)
     mEdges = std::move(edges);
 }
 
+std::unique_ptr<AbstractMesh> LineMesh::copy() const
+{
+    return nullptr;
+}
+
+LineMesh::MeshType LineMesh::getType() const
+{
+    return LineMesh::MeshType::LINE;
+}
+
 std::vector<unsigned> LineMesh::getEdgeNodeIds() const
 {
     std::vector<unsigned> ids(2*mEdges.size());
diff --git a/src/mesh/LineMesh.h b/src/mesh/LineMesh.h
index 0116036..3cf98ad 100644
--- a/src/mesh/LineMesh.h
+++ b/src/mesh/LineMesh.h
@@ -20,10 +20,9 @@ public:
 
     std::vector<unsigned> getEdgeNodeIds() const;
 
-    MeshType getType() const override
-    {
-        return MeshType::LINE;
-    }
+    MeshType getType() const override;
+
+    std::unique_ptr<AbstractMesh> copy() const override;
 
 private:
     VecEdges mEdges;
diff --git a/src/mesh/MeshPrimitives.cpp b/src/mesh/MeshPrimitives.cpp
index 066d3ae..38308ca 100644
--- a/src/mesh/MeshPrimitives.cpp
+++ b/src/mesh/MeshPrimitives.cpp
@@ -2,6 +2,8 @@
 
 #include "MeshBuilder.h"
 
+#include <math.h>
+
 #include <iostream>
 
 std::unique_ptr<TriMesh> MeshPrimitives::buildRectangleAsTriMesh()
@@ -29,6 +31,85 @@ std::unique_ptr<TriMesh> MeshPrimitives::buildRectangleAsTriMesh()
     return MeshBuilder::buildTriMesh(locations, edge_ids, face_ids);
 }
 
+std::unique_ptr<TriMesh> MeshPrimitives::buildRoundedRectangleAsTriMesh(double radius, double aspect_ratio, unsigned num_segments)
+{
+    unsigned num_fans = 4;
+    unsigned num_nodes_per_fan = num_segments + 2;
+    VecPoints locations(num_fans * num_nodes_per_fan);
+
+    double rect_start_x = radius;
+    double rect_end_x = 1.0 - radius;
+    double rect_end_y = 1.0 - radius;
+
+    double delta_theta = (M_PI/4.0) / double (num_segments);
+    double running_theta = 0;
+
+    locations[0] = {rect_end_x, radius};
+    unsigned offset = 1;
+    for (unsigned idx=0; idx<=num_segments; idx++)
+    {
+        locations[offset + idx] = {rect_end_x + radius*sin(running_theta), radius*(1.0 - cos(running_theta))};
+        running_theta += delta_theta;
+    }
+    offset += num_segments;
+
+    locations[offset] = {rect_end_x, rect_end_y};
+    offset++;
+    running_theta = 0;
+    for (unsigned idx=0; idx<=num_segments;idx++)
+    {
+        locations[offset + idx] = {rect_end_x + radius*cos(running_theta), rect_end_y + radius*sin(running_theta)};
+        running_theta += delta_theta;
+    }
+    offset += num_segments;
+
+    locations[offset] = {rect_start_x, rect_end_y};
+    offset ++;
+    running_theta = 0;
+    for (unsigned idx=0; idx<=num_segments;idx++)
+    {
+        locations[offset + idx] = {rect_start_x - radius*sin(running_theta), rect_end_y + radius*cos(running_theta)};
+        running_theta += delta_theta;
+    }
+    offset += num_segments;
+
+    locations[offset] = {rect_start_x, radius};
+    offset++;
+    running_theta = 0;
+    for (unsigned idx=0; idx<=num_segments;idx++)
+    {
+        locations[offset + idx] = {rect_start_x - radius*cos(running_theta), radius *(1 - sin(running_theta))};
+        running_theta += delta_theta;
+    }
+
+    unsigned num_edges_per_fan = 2*num_segments + 1;
+    unsigned num_inner_rect_edges = 3*num_fans;
+    EdgeIds edge_ids(num_edges_per_fan*num_fans + num_inner_rect_edges + 1);
+
+    // Fan edges
+    for (unsigned jdx=0; jdx< num_fans; jdx++)
+    {
+        unsigned node_offset = jdx*num_nodes_per_fan;
+        unsigned edge_offset = jdx*num_edges_per_fan;
+
+        // Inner edges
+        for(unsigned idx=0; idx<=num_segments; idx++)
+        {
+            edge_ids[edge_offset + idx] = {node_offset, node_offset + idx + 1};
+        }
+
+        // Outer edges
+        for(unsigned idx=0; idx<num_segments; idx++)
+        {
+            edge_ids[edge_offset + num_segments + 1 + idx] = {node_offset + idx + 1, node_offset + idx + 2};
+        }
+    }
+
+    // Inner rect edges
+    unsigned edge_offset = num_edges_per_fan*num_fans;
+
+}
+
 std::unique_ptr<LineMesh> MeshPrimitives::buildRectangleAsLineMesh()
 {
     VecPoints locations = {
diff --git a/src/mesh/MeshPrimitives.h b/src/mesh/MeshPrimitives.h
index a151764..6c87c43 100644
--- a/src/mesh/MeshPrimitives.h
+++ b/src/mesh/MeshPrimitives.h
@@ -14,4 +14,6 @@ public:
     static std::unique_ptr<TriMesh> buildExplodedGridAsTriMesh(unsigned numX, unsigned numY);
 
     static std::unique_ptr<LineMesh> buildExplodedGridAsLineMesh(unsigned numX, unsigned numY);
+
+    static std::unique_ptr<TriMesh> buildRoundedRectangleAsTriMesh(double radius, double aspect_ratio = 1.0, unsigned num_segments = 4);
 };
diff --git a/src/mesh/Node.cpp b/src/mesh/Node.cpp
index f35ba6f..fde89d5 100644
--- a/src/mesh/Node.cpp
+++ b/src/mesh/Node.cpp
@@ -42,4 +42,75 @@ std::vector<double> Node::getVectorAttribute(const std::string& tag) const
     return {};
 }
 
+const Point& Node::getPoint() const
+{
+    return mPoint;
+}
+
+void Node::scale(double x, double y)
+{
+    mPoint.scale(x, y);
+}
+
+void Node::translate(double x, double y, double z)
+{
+    mPoint.translate(x, y, z);
+}
+
+bool Node::isCoincident(Node* node) const
+{
+    return node->getPoint() == mPoint;
+}
+
+void Node::setState(State state)
+{
+    mState = state;
+}
+
+Node::State Node::getState() const
+{
+    return mState;
+}
+
+void Node::clearConnectivity()
+{
+    mAssociatedEdgeIds.clear();
+    mAssociatedFaceIds.clear();
+}
+
+unsigned Node::getNumConnectedEdges() const
+{
+    return mAssociatedEdgeIds.size();
+}
+
+unsigned Node::getNumConnectedFaces() const
+{
+    return mAssociatedFaceIds.size();
+}
+
+void Node::associateEdge(unsigned edgeId)
+{
+    mAssociatedEdgeIds.push_back(edgeId);
+}
+
+void Node::associateFace(unsigned faceId)
+{
+    mAssociatedFaceIds.push_back(faceId);
+}
+
+unsigned Node::getConnectedEdgeId(std::size_t idx) const
+{
+    return mAssociatedEdgeIds[idx];
+}
+
+unsigned Node::getConnectedFaceId(std::size_t idx) const
+{
+    return mAssociatedFaceIds[idx];
+}
+
+void Node::setIndex(std::size_t idx)
+{
+    mIndex = idx;
+}
+
 
diff --git a/src/mesh/Node.h b/src/mesh/Node.h
index 748dab1..d91e7e1 100644
--- a/src/mesh/Node.h
+++ b/src/mesh/Node.h
@@ -6,41 +6,65 @@
 #include <string>
 #include <vector>
 
-
 class Node
 {
 public:
+
+    enum class State
+    {
+        HEALTHY,
+        DIRTY
+    };
+
     Node(const Point& p, unsigned index = 0);
 
     static std::unique_ptr<Node> Create(const Point& p, unsigned index = 0);
 
     ~Node();
 
-    unsigned getIndex() const;
+    void associateEdge(unsigned edgeId);
 
-    void updateIndex(unsigned index);
-
-    const Point& getPoint() const
-    {
-        return mPoint;
-    }
+    void associateFace(unsigned faceId);
 
     void addVectorAttribute(const std::string& tag, const std::vector<double>& values);
 
+    void clearConnectivity();
+
+    unsigned getIndex() const;
+
+    unsigned getNumConnectedEdges() const;
+
+    unsigned getNumConnectedFaces() const;
+
+    unsigned getConnectedEdgeId(std::size_t idx) const;
+
+    unsigned getConnectedFaceId(std::size_t idx) const;
+
+    State getState() const;
+
+    const Point& getPoint() const;
+
     std::vector<double> getVectorAttribute(const std::string& tag) const;
 
-    void scale(double x, double y)
-    {
-        mPoint.scale(x, y);
-    }
+    bool isCoincident(Node* node) const;
 
-    void translate(double x, double y, double z = 0.0)
-    {
-        mPoint.translate(x, y, z);
-    }
+    void setState(State state);
+
+    void setIndex(std::size_t idx);
+
+    void updateIndex(unsigned index);
+
+    void scale(double x, double y);
+
+    void translate(double x, double y, double z = 0.0);
 
 private:
     std::unordered_map<std::string, std::vector<double> > mVectorAttributes;
     unsigned mIndex{0};
     Point mPoint;
+
+    std::vector<unsigned> mAssociatedEdgeIds;
+    std::vector<unsigned> mAssociatedFaceIds;
+
+    State mState{State::HEALTHY};
 };
diff --git a/src/mesh/TriFace.cpp b/src/mesh/TriFace.cpp
index 461a0fb..a61b3d2 100644
--- a/src/mesh/TriFace.cpp
+++ b/src/mesh/TriFace.cpp
@@ -25,3 +25,51 @@ std::vector<unsigned> TriFace::getNodeIds() const
 {
     return {mEdge0->getNode0Id(), mEdge0->getNode1Id(), mEdge1->getNode1Id()};
 }
+
+unsigned TriFace::getNumNodes() const
+{
+    return 3;
+}
+
+void TriFace::replaceEdge(Edge* original, Edge* replacement)
+{
+    if (original == mEdge0)
+    {
+        mEdge0 = replacement;
+    }
+    else if (original == mEdge1)
+    {
+        mEdge1 = replacement;
+    }
+    else if (original == mEdge2)
+    {
+        mEdge2 = replacement;
+    }
+}
+
+unsigned TriFace::getEdge0Id () const
+{
+    return mEdge0->getId();
+}
+
+unsigned TriFace::getEdge1Id () const
+{
+    return mEdge1->getId();
+}
+
+unsigned TriFace::getEdge2Id () const
+{
+    return mEdge2->getId();
+}
+
+std::vector<unsigned> TriFace::getEdgeIds() const
+{
+    return {mEdge0->getId(), mEdge1->getId(), mEdge2->getId()};
+}
+
+void TriFace::associateWidthEdges()
+{
+    mEdge0->associateFace(mId);
+    mEdge1->associateFace(mId);
+    mEdge2->associateFace(mId);
+}
diff --git a/src/mesh/TriFace.h b/src/mesh/TriFace.h
index 32d70e9..7878117 100644
--- a/src/mesh/TriFace.h
+++ b/src/mesh/TriFace.h
@@ -11,12 +11,22 @@ public:
 
     ~TriFace();
 
-    std::vector<unsigned> getNodeIds() const override;
-
     static std::unique_ptr<TriFace> Create(Edge* edge0, Edge* edge1, Edge* edge2, unsigned id=0);
 
-private:
+    void associateWidthEdges() override;
 
+    std::vector<unsigned> getNodeIds() const override;
+
+    unsigned getNumNodes() const override;
+
+    void replaceEdge(Edge* original, Edge* replacement);
+
+    unsigned getEdge0Id () const;
+    unsigned getEdge1Id () const;
+    unsigned getEdge2Id () const;
+    std::vector<unsigned> getEdgeIds() const override;
+
+private:
     Edge* mEdge0{nullptr};
     Edge* mEdge1{nullptr};
     Edge* mEdge2{nullptr};
diff --git a/src/mesh/TriMesh.cpp b/src/mesh/TriMesh.cpp
index 5251982..18c29f4 100644
--- a/src/mesh/TriMesh.cpp
+++ b/src/mesh/TriMesh.cpp
@@ -1,6 +1,5 @@
 #include "TriMesh.h"
 
-#include "Node.h"
 #include "Edge.h"
 #include "TriFace.h"
 
@@ -9,43 +8,39 @@ TriMesh::~TriMesh()
 
 }
 
-void TriMesh::populate(VecNodes& nodes, VecEdges& edges, VecFaces& faces)
+AbstractMesh::MeshType TriMesh::getType() const
 {
-    mNodes = std::move(nodes);
-    mEdges = std::move(edges);
-    mFaces = std::move(faces);
+    return AbstractMesh::MeshType::TRI;
 }
 
-std::vector<unsigned> TriMesh::getFaceNodeIds() const
+std::unique_ptr<AbstractMesh> TriMesh::copy() const
 {
-    unsigned nodes_per_face = 3;
-    std::vector<unsigned> ids(nodes_per_face*mFaces.size());
-
-    for(std::size_t idx=0; idx<mFaces.size(); idx++)
+    VecNodes nodes(mNodes.size());
+    unsigned count = 0;
+    for (auto& node : mNodes)
     {
-        const auto nodeIds = mFaces[idx]->getNodeIds();
-        for(std::size_t jdx=0; jdx<nodes_per_face; jdx++)
-        {
-            ids[nodes_per_face*idx + jdx] = nodeIds[jdx];
-        }
+        nodes[count] = std::make_unique<Node>(node->getPoint());
+        count++;
     }
-    return ids;
-}
 
-std::vector<std::vector<double> > TriMesh::getFaceVectorAttributes(const std::string& tag)
-{
-    std::vector<std::vector<double> > attribs(mFaces.size());
-    for(std::size_t idx=0; idx<mFaces.size(); idx++)
+    VecEdges edges(mEdges.size());
+    count = 0;
+    for (auto& edge : mEdges)
     {
-        attribs[idx] = {mFaces[idx]->getVectorAttribute(tag)};
+        edges[count] = std::make_unique<Edge>(nodes[edge->getNode0Id()].get(), nodes[edge->getNode0Id()].get());
+        count++;
     }
-    return attribs;
-}
 
-void TriMesh::addConstantFaceVectorAttribute(const std::string& tag, const std::vector<double>& values)
-{
-    for (const auto& face : mFaces)
+    VecFaces faces(mFaces.size());
+    count = 0;
+    for (auto& face : mFaces)
     {
-        face->addVectorAttribute(tag, values);
+        auto ids = face->getEdgeIds();
+        faces[count] = std::make_unique<TriFace>(edges[ids[0]].get(), edges[ids[1]].get(), edges[ids[2]].get());
+        count++;
     }
+
+    auto mesh = std::make_unique<TriMesh>();
+    mesh->populate(nodes, edges, faces);
+    return mesh;
 }
diff --git a/src/mesh/TriMesh.h b/src/mesh/TriMesh.h
index 79ce181..63700ee 100644
--- a/src/mesh/TriMesh.h
+++ b/src/mesh/TriMesh.h
@@ -1,40 +1,15 @@
 #pragma once
 
-#include "AbstractMesh.h"
+#include "FaceMesh.h"
 
-#include <string>
-#include <unordered_map>
-
-class Edge;
-class TriFace;
-
-using EdgePtr = std::unique_ptr<Edge>;
-using TriFacePtr = std::unique_ptr<TriFace>;
-
-using VecEdges = std::vector<EdgePtr>;
-using VecFaces = std::vector<TriFacePtr>;
-
-class TriMesh : public AbstractMesh
+class TriMesh : public FaceMesh
 {
 public:
     TriMesh() = default;
 
     ~TriMesh();
 
-    void populate(VecNodes& nodes, VecEdges& edges, VecFaces& faces);
+    std::unique_ptr<AbstractMesh> copy() const override;
 
-    std::vector<unsigned> getFaceNodeIds() const;
-
-    void addConstantFaceVectorAttribute(const std::string& tag, const std::vector<double>& values);
-
-    std::vector<std::vector<double> > getFaceVectorAttributes(const std::string& tag);
-
-    MeshType getType() const
-    {
-        return MeshType::TRI;
-    }
-
-private:
-    VecEdges mEdges;
-    VecFaces mFaces;
+    MeshType getType() const;
 };
diff --git a/src/ui_elements/CMakeLists.txt b/src/ui_elements/CMakeLists.txt
index 81e0308..c3a7619 100644
--- a/src/ui_elements/CMakeLists.txt
+++ b/src/ui_elements/CMakeLists.txt
@@ -16,6 +16,7 @@ list(APPEND ui_elements_LIB_INCLUDES
         ui_events/ResizeEvent.cpp
         widgets/Widget.cpp
         widgets/Button.cpp
+        widgets/ButtonGroup.cpp
         widgets/Label.cpp
         widgets/HorizontalSpacer.cpp
         widgets/VerticalSpacer.cpp
diff --git a/src/ui_elements/widgets/ButtonGroup.cpp b/src/ui_elements/widgets/ButtonGroup.cpp
new file mode 100644
index 0000000..e69de29
diff --git a/src/ui_elements/widgets/ButtonGroup.h b/src/ui_elements/widgets/ButtonGroup.h
new file mode 100644
index 0000000..e866a5e
--- /dev/null
+++ b/src/ui_elements/widgets/ButtonGroup.h
@@ -0,0 +1,23 @@
+#pragma once
+
+#include "Widget.h"
+
+class ButtonGroup : public Widget
+{
+public:
+
+    enum class Orientation
+    {
+        HORIZONTAL,
+        VERTICAL
+    };
+
+    ButtonGroup();
+
+    ~ButtonGroup();
+
+    static std::unique_ptr<ButtonGroup> Create();
+
+private:
+    bool mExclusiveActivation{true};
+};