diff --git a/src/libslic3r/Model.cpp b/src/libslic3r/Model.cpp
index c9a097aea3..27ffef636e 100644
--- a/src/libslic3r/Model.cpp
+++ b/src/libslic3r/Model.cpp
@@ -951,25 +951,54 @@ bool ModelObject::needed_repair() const
     return false;
 }
 
-void ModelObject::cut(coordf_t z, Model* model) const
+template<class T> static void cut_reset_transform(T *thing) {
+    const Vec3d offset = thing->get_offset();
+    thing->set_transformation(Geometry::Transformation());
+    thing->set_offset(offset);
+}
+
+ModelObjectPtrs ModelObject::cut(size_t instance, coordf_t z)
 {
-    // clone this one to duplicate instances, materials etc.
-    ModelObject* upper = model->add_object(*this);
-    ModelObject* lower = model->add_object(*this);
+    // Clone the object to duplicate instances, materials etc.
+    ModelObject* upper = ModelObject::new_clone(*this);
+    ModelObject* lower = ModelObject::new_clone(*this);
+    upper->set_model(nullptr);
+    lower->set_model(nullptr);
     upper->sla_support_points.clear();
     lower->sla_support_points.clear();
     upper->clear_volumes();
     lower->clear_volumes();
     upper->input_file = "";
     lower->input_file = "";
-    
-    for (ModelVolume *volume : this->volumes) {
+
+    const auto instance_matrix = instances[instance]->get_matrix(true);
+
+    // Because transformations are going to be applied to meshes directly,
+    // we reset transformation of all instances and volumes,
+    // _except_ for translation, which is preserved in the transformation matrix
+    // and not applied to the mesh transform.
+    // TODO: Do the same for Z-rotation as well?
+
+    // Convert z from relative to bb's base to object coordinates
+    // FIXME: doesn't work well for rotated objects
+    const auto bb = instance_bounding_box(instance, true);
+    z -= bb.min(2);
+
+    for (auto *instance : upper->instances) { cut_reset_transform(instance); }
+    for (auto *instance : lower->instances) { cut_reset_transform(instance); }
+
+    for (ModelVolume *volume : volumes) {
         if (! volume->is_model_part()) {
             // don't cut modifiers
             upper->add_volume(*volume);
             lower->add_volume(*volume);
         } else {
             TriangleMesh upper_mesh, lower_mesh;
+
+            // Transform the mesh by the object transformation matrix
+            volume->mesh.transform(instance_matrix * volume->get_matrix(true));
+            cut_reset_transform(volume);
+
             TriangleMeshSlicer tms(&volume->mesh);
             tms.cut(z, &upper_mesh, &lower_mesh);
 
@@ -977,7 +1006,7 @@ void ModelObject::cut(coordf_t z, Model* model) const
             lower_mesh.repair();
             upper_mesh.reset_repair_stats();
             lower_mesh.reset_repair_stats();
-            
+
             if (upper_mesh.facets_count() > 0) {
                 ModelVolume* vol    = upper->add_volume(upper_mesh);
                 vol->name           = volume->name;
@@ -992,6 +1021,15 @@ void ModelObject::cut(coordf_t z, Model* model) const
             }
         }
     }
+
+    upper->invalidate_bounding_box();
+    lower->invalidate_bounding_box();
+
+    ModelObjectPtrs res;
+    if (upper->volumes.size() > 0) { res.push_back(upper); }
+    if (lower->volumes.size() > 0) { res.push_back(lower); }
+
+    return res;
 }
 
 void ModelObject::split(ModelObjectPtrs* new_objects)
@@ -1011,7 +1049,8 @@ void ModelObject::split(ModelObjectPtrs* new_objects)
         
         mesh->repair();
         
-        ModelObject* new_object = m_model->add_object();
+        // XXX: this seems to be the only real usage of m_model, maybe refactor this so that it's not needed?
+        ModelObject* new_object = m_model->add_object();    
 		new_object->name   = this->name;
 		new_object->config = this->config;
 		new_object->instances.reserve(this->instances.size());
diff --git a/src/libslic3r/Model.hpp b/src/libslic3r/Model.hpp
index 354d71dc46..8e3ee3f306 100644
--- a/src/libslic3r/Model.hpp
+++ b/src/libslic3r/Model.hpp
@@ -237,7 +237,7 @@ public:
     size_t materials_count() const;
     size_t facets_count() const;
     bool needed_repair() const;
-    void cut(coordf_t z, Model* model) const;
+    ModelObjectPtrs cut(size_t instance, coordf_t z);
     void split(ModelObjectPtrs* new_objects);
     void repair();
 
@@ -607,7 +607,7 @@ public:
     bool         delete_object(ModelID id);
     bool         delete_object(ModelObject* object);
     void         clear_objects();
-    
+
     ModelMaterial* add_material(t_model_material_id material_id);
     ModelMaterial* add_material(t_model_material_id material_id, const ModelMaterial &other);
     ModelMaterial* get_material(t_model_material_id material_id) {
diff --git a/src/slic3r.cpp b/src/slic3r.cpp
index e9fa54ce03..376ade95a4 100644
--- a/src/slic3r.cpp
+++ b/src/slic3r.cpp
@@ -192,20 +192,21 @@ int main(int argc, char **argv)
             model.repair();
             model.translate(0, 0, - model.bounding_box().min(2));
             if (! model.objects.empty()) {
-                Model out;
-                model.objects.front()->cut(cli_config.cut, &out);
-                ModelObject &upper = *out.objects[0];
-                ModelObject &lower = *out.objects[1];
-                // Use the input name and trim off the extension.
-                std::string outfile = cli_config.output.value;
-                if (outfile.empty()) 
-                    outfile = model.objects.front()->input_file;
-                outfile = outfile.substr(0, outfile.find_last_of('.'));
-                std::cerr << outfile << "\n";
-                if (upper.facets_count() > 0)
-                    upper.mesh().write_binary((outfile + "_upper.stl").c_str());
-                if (lower.facets_count() > 0)
-                    lower.mesh().write_binary((outfile + "_lower.stl").c_str());
+                // XXX
+                // Model out;
+                // model.objects.front()->cut(cli_config.cut, &out);
+                // ModelObject &upper = *out.objects[0];
+                // ModelObject &lower = *out.objects[1];
+                // // Use the input name and trim off the extension.
+                // std::string outfile = cli_config.output.value;
+                // if (outfile.empty())
+                //     outfile = model.objects.front()->input_file;
+                // outfile = outfile.substr(0, outfile.find_last_of('.'));
+                // std::cerr << outfile << "\n";
+                // if (upper.facets_count() > 0)
+                //     upper.mesh().write_binary((outfile + "_upper.stl").c_str());
+                // if (lower.facets_count() > 0)
+                //     lower.mesh().write_binary((outfile + "_lower.stl").c_str());
             }
         } else if (cli_config.slice) {
             std::string outfile = cli_config.output.value;
diff --git a/src/slic3r/GUI/3DScene.cpp b/src/slic3r/GUI/3DScene.cpp
index 45c700482e..2350cdffcc 100644
--- a/src/slic3r/GUI/3DScene.cpp
+++ b/src/slic3r/GUI/3DScene.cpp
@@ -1915,11 +1915,6 @@ void _3DScene::set_bed_shape(wxGLCanvas* canvas, const Pointfs& shape)
     s_canvas_mgr.set_bed_shape(canvas, shape);
 }
 
-void _3DScene::set_cutting_plane(wxGLCanvas* canvas, float z, const ExPolygons& polygons)
-{
-    s_canvas_mgr.set_cutting_plane(canvas, z, polygons);
-}
-
 void _3DScene::set_color_by(wxGLCanvas* canvas, const std::string& value)
 {
     s_canvas_mgr.set_color_by(canvas, value);
diff --git a/src/slic3r/GUI/3DScene.hpp b/src/slic3r/GUI/3DScene.hpp
index 5d81b57bbd..16523af686 100644
--- a/src/slic3r/GUI/3DScene.hpp
+++ b/src/slic3r/GUI/3DScene.hpp
@@ -577,8 +577,6 @@ public:
 
     static void set_bed_shape(wxGLCanvas* canvas, const Pointfs& shape);
 
-    static void set_cutting_plane(wxGLCanvas* canvas, float z, const ExPolygons& polygons);
-
     static void set_color_by(wxGLCanvas* canvas, const std::string& value);
 
     static bool is_layers_editing_enabled(wxGLCanvas* canvas);
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 1f8ca9aaee..6e47c08673 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -641,70 +641,6 @@ void GLCanvas3D::Axes::render(bool depth_test) const
     ::glEnd();
 }
 
-GLCanvas3D::CuttingPlane::CuttingPlane()
-    : m_z(-1.0f)
-{
-}
-
-bool GLCanvas3D::CuttingPlane::set(float z, const ExPolygons& polygons)
-{
-    m_z = z;
-
-    // grow slices in order to display them better
-    ExPolygons expolygons = offset_ex(polygons, (float)scale_(0.1));
-    Lines lines = to_lines(expolygons);
-    return m_lines.set_from_lines(lines, m_z);
-}
-
-void GLCanvas3D::CuttingPlane::render(const BoundingBoxf3& bb) const
-{
-    _render_plane(bb);
-    _render_contour();
-}
-
-void GLCanvas3D::CuttingPlane::_render_plane(const BoundingBoxf3& bb) const
-{
-    if (m_z >= 0.0f)
-    {
-        ::glDisable(GL_CULL_FACE);
-        ::glEnable(GL_BLEND);
-        ::glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
-
-        float margin = 20.0f;
-        float min_x = bb.min(0) - margin;
-        float max_x = bb.max(0) + margin;
-        float min_y = bb.min(1) - margin;
-        float max_y = bb.max(1) + margin;
-
-        ::glBegin(GL_QUADS);
-        ::glColor4f(0.8f, 0.8f, 0.8f, 0.5f);
-        ::glVertex3f(min_x, min_y, m_z);
-        ::glVertex3f(max_x, min_y, m_z);
-        ::glVertex3f(max_x, max_y, m_z);
-        ::glVertex3f(min_x, max_y, m_z);
-        ::glEnd();
-
-        ::glEnable(GL_CULL_FACE);
-        ::glDisable(GL_BLEND);
-    }
-}
-
-void GLCanvas3D::CuttingPlane::_render_contour() const
-{
-    ::glEnableClientState(GL_VERTEX_ARRAY);
-
-    if (m_z >= 0.0f)
-    {
-        unsigned int lines_vcount = m_lines.get_vertices_count();
-
-        ::glLineWidth(2.0f);
-        ::glColor3f(0.0f, 0.0f, 0.0f);
-        ::glVertexPointer(3, GL_FLOAT, 0, (GLvoid*)m_lines.get_vertices());
-        ::glDrawArrays(GL_LINES, 0, (GLsizei)lines_vcount);
-    }
-
-    ::glDisableClientState(GL_VERTEX_ARRAY);
-}
 
 GLCanvas3D::Shader::Shader()
     : m_shader(nullptr)
@@ -2380,6 +2316,13 @@ bool GLCanvas3D::Gizmos::init(GLCanvas3D& parent)
 
     m_gizmos.insert(GizmosMap::value_type(Flatten, gizmo));
 
+    gizmo = new GLGizmoCut(parent);
+    if (! gizmo->init()) {
+        return false;
+    }
+
+    m_gizmos.insert({ Cut, gizmo });
+
     gizmo = new GLGizmoSlaSupports(parent);
     if (gizmo == nullptr)
         return false;
@@ -2391,7 +2334,6 @@ bool GLCanvas3D::Gizmos::init(GLCanvas3D& parent)
 
     m_gizmos.insert(GizmosMap::value_type(SlaSupports, gizmo));
 
-
     return true;
 }
 
@@ -2764,6 +2706,13 @@ void GLCanvas3D::Gizmos::render_overlay(const GLCanvas3D& canvas) const
     ::glPopMatrix();
 }
 
+void GLCanvas3D::Gizmos::create_external_gizmo_widgets(wxWindow *parent)
+{
+    for (auto &entry : m_gizmos) {
+        entry.second->create_external_gizmo_widgets(parent);
+    }
+}
+
 void GLCanvas3D::Gizmos::_reset()
 {
     for (GizmosMap::value_type& gizmo : m_gizmos)
@@ -3166,6 +3115,7 @@ GLCanvas3D::GLCanvas3D(wxGLCanvas* canvas)
     , m_regenerate_volumes(true)
     , m_color_by("volume")
     , m_reload_delayed(false)
+    , m_external_gizmo_widgets_parent(nullptr)
 {
     if (m_canvas != nullptr)
     {
@@ -3267,8 +3217,16 @@ bool GLCanvas3D::init(bool useVBOs, bool use_legacy_opengl)
     if (!m_volumes.empty())
         m_volumes.finalize_geometry(m_use_VBOs);
 
-    if (m_gizmos.is_enabled() && !m_gizmos.init(*this))
-        return false;
+    if (m_gizmos.is_enabled()) {
+        if (! m_gizmos.init(*this)) { 
+            return false; 
+        }
+
+        if (m_external_gizmo_widgets_parent != nullptr) {
+            m_gizmos.create_external_gizmo_widgets(m_external_gizmo_widgets_parent);
+            m_canvas->GetParent()->Layout();
+        }
+    }
 
     if (!_init_toolbar())
         return false;
@@ -3371,11 +3329,6 @@ void GLCanvas3D::set_axes_length(float length)
     m_axes.length = length;
 }
 
-void GLCanvas3D::set_cutting_plane(float z, const ExPolygons& polygons)
-{
-    m_cutting_plane.set(z, polygons);
-}
-
 void GLCanvas3D::set_color_by(const std::string& value)
 {
     m_color_by = value;
@@ -3629,7 +3582,6 @@ void GLCanvas3D::render()
 #endif // ENABLE_GIZMOS_ON_TOP
 
     _render_current_gizmo();
-    _render_cutting_plane();
 #if ENABLE_SHOW_CAMERA_TARGET
     _render_camera_target();
 #endif // ENABLE_SHOW_CAMERA_TARGET
@@ -4524,6 +4476,11 @@ void GLCanvas3D::set_tooltip(const std::string& tooltip) const
     }
 }
 
+void GLCanvas3D::set_external_gizmo_widgets_parent(wxWindow *parent)
+{
+    m_external_gizmo_widgets_parent = parent;
+}
+
 bool GLCanvas3D::_is_shown_on_screen() const
 {
     return (m_canvas != nullptr) ? m_canvas->IsShownOnScreen() : false;
@@ -4624,14 +4581,6 @@ bool GLCanvas3D::_init_toolbar()
     if (!m_toolbar.add_item(item))
         return false;
 
-    item.name = "cut";
-    item.tooltip = GUI::L_str("Cut...");
-    item.sprite_id = 7;
-    item.is_toggable = false;
-    item.action_event = EVT_GLTOOLBAR_CUT;
-    if (!m_toolbar.add_item(item))
-        return false;
-
     if (!m_toolbar.add_separator())
         return false;
 
@@ -5030,11 +4979,6 @@ void GLCanvas3D::_render_selection() const
         m_selection.render();
 }
 
-void GLCanvas3D::_render_cutting_plane() const
-{
-    m_cutting_plane.render(volumes_bounding_box());
-}
-
 void GLCanvas3D::_render_warning_texture() const
 {
     if (!m_warning_texture_enabled)
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index 3f76f5b4e7..cf7c840854 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -16,6 +16,7 @@ class wxKeyEvent;
 class wxMouseEvent;
 class wxTimerEvent;
 class wxPaintEvent;
+class wxGLCanvas;
 
 
 namespace Slic3r {
@@ -219,23 +220,6 @@ class GLCanvas3D
         void render(bool depth_test) const;
     };
 
-    class CuttingPlane
-    {
-        float m_z;
-        GeometryBuffer m_lines;
-
-    public:
-        CuttingPlane();
-
-        bool set(float z, const ExPolygons& polygons);
-
-        void render(const BoundingBoxf3& bb) const;
-
-    private:
-        void _render_plane(const BoundingBoxf3& bb) const;
-        void _render_contour() const;
-    };
-
     class Shader
     {
         GLShader* m_shader;
@@ -479,6 +463,8 @@ public:
         Selection();
 
         void set_volumes(GLVolumePtrs* volumes);
+
+        Model* get_model() const { return m_model; }
         void set_model(Model* model);
 
         EMode get_mode() const { return m_mode; }
@@ -580,6 +566,7 @@ private:
             Rotate,
             Flatten,
             SlaSupports,
+            Cut,
             Num_Types
         };
 
@@ -642,6 +629,8 @@ private:
 
         void render_overlay(const GLCanvas3D& canvas) const;
 
+        void create_external_gizmo_widgets(wxWindow *parent);
+
     private:
         void _reset();
 
@@ -698,7 +687,6 @@ private:
     Camera m_camera;
     Bed m_bed;
     Axes m_axes;
-    CuttingPlane m_cutting_plane;
     LayersEditing m_layers_editing;
     Shader m_shader;
     Mouse m_mouse;
@@ -734,6 +722,8 @@ private:
 
     GCodePreviewVolumeIndex m_gcode_preview_volume_index;
 
+    wxWindow *m_external_gizmo_widgets_parent;
+
     void post_event(wxEvent &&event);
     void viewport_changed();
 
@@ -775,8 +765,6 @@ public:
 
     void set_axes_length(float length);
 
-    void set_cutting_plane(float z, const ExPolygons& polygons);
-
     void set_color_by(const std::string& value);
 
     float get_camera_zoom() const;
@@ -855,6 +843,8 @@ public:
 
     void set_tooltip(const std::string& tooltip) const;
 
+    void set_external_gizmo_widgets_parent(wxWindow *parent);
+
 private:
     bool _is_shown_on_screen() const;
     void _force_zoom_to_bed();
@@ -881,7 +871,6 @@ private:
     void _render_axes(bool depth_test) const;
     void _render_objects() const;
     void _render_selection() const;
-    void _render_cutting_plane() const;
     void _render_warning_texture() const;
     void _render_legend_texture() const;
     void _render_layer_editing_overlay() const;
diff --git a/src/slic3r/GUI/GLCanvas3DManager.cpp b/src/slic3r/GUI/GLCanvas3DManager.cpp
index 7172195200..abf7834605 100644
--- a/src/slic3r/GUI/GLCanvas3DManager.cpp
+++ b/src/slic3r/GUI/GLCanvas3DManager.cpp
@@ -293,13 +293,6 @@ void GLCanvas3DManager::set_bed_shape(wxGLCanvas* canvas, const Pointfs& shape)
         it->second->set_bed_shape(shape);
 }
 
-void GLCanvas3DManager::set_cutting_plane(wxGLCanvas* canvas, float z, const ExPolygons& polygons)
-{
-    CanvasesMap::iterator it = _get_canvas(canvas);
-    if (it != m_canvases.end())
-        it->second->set_cutting_plane(z, polygons);
-}
-
 void GLCanvas3DManager::set_color_by(wxGLCanvas* canvas, const std::string& value)
 {
     CanvasesMap::iterator it = _get_canvas(canvas);
diff --git a/src/slic3r/GUI/GLCanvas3DManager.hpp b/src/slic3r/GUI/GLCanvas3DManager.hpp
index 237d3558c4..097d3a118f 100644
--- a/src/slic3r/GUI/GLCanvas3DManager.hpp
+++ b/src/slic3r/GUI/GLCanvas3DManager.hpp
@@ -99,8 +99,6 @@ public:
 
     void set_bed_shape(wxGLCanvas* canvas, const Pointfs& shape);
 
-    void set_cutting_plane(wxGLCanvas* canvas, float z, const ExPolygons& polygons);
-
     void set_color_by(wxGLCanvas* canvas, const std::string& value);
 
     bool is_layers_editing_enabled(wxGLCanvas* canvas) const;
diff --git a/src/slic3r/GUI/GLGizmo.cpp b/src/slic3r/GUI/GLGizmo.cpp
index 8cbb850685..b8988077e7 100644
--- a/src/slic3r/GUI/GLGizmo.cpp
+++ b/src/slic3r/GUI/GLGizmo.cpp
@@ -1,4 +1,4 @@
-#include "../../libslic3r/libslic3r.h"
+#include "libslic3r/libslic3r.h"
 #include "GLGizmo.hpp"
 
 #include "GUI.hpp"
@@ -8,15 +8,29 @@
 #include "PresetBundle.hpp"
 
 #include <Eigen/Dense>
-#include "../../libslic3r/Geometry.hpp"
+#include "libslic3r/Geometry.hpp"
 
 #include <igl/unproject_onto_mesh.h>
 #include <GL/glew.h>
 
 #include <SLA/SLASupportTree.hpp>
 
-#include <iostream>
+#include <cstdio>
 #include <numeric>
+#include <algorithm>
+
+#include <wx/sizer.h>
+#include <wx/panel.h>
+#include <wx/button.h>
+#include <wx/checkbox.h>
+#include <wx/stattext.h>
+#include <wx/debug.h>
+
+#include "GUI.hpp"
+#include "GUI_Utils.hpp"
+#include "GUI_App.hpp"
+
+// TODO: Display tooltips quicker on Linux
 
 static const float DEFAULT_BASE_COLOR[3] = { 0.625f, 0.625f, 0.625f };
 static const float DEFAULT_DRAG_COLOR[3] = { 1.0f, 1.0f, 1.0f };
@@ -252,6 +266,8 @@ void GLGizmoBase::render_grabbers_for_picking(const BoundingBoxf3& box) const
     }
 }
 
+void GLGizmoBase::create_external_gizmo_widgets(wxWindow *parent) {}
+
 void GLGizmoBase::set_tooltip(const std::string& tooltip) const
 {
     m_parent.set_tooltip(tooltip);
@@ -259,9 +275,10 @@ void GLGizmoBase::set_tooltip(const std::string& tooltip) const
 
 std::string GLGizmoBase::format(float value, unsigned int decimals) const
 {
-    char buf[1024];
-    ::sprintf(buf, "%.*f", decimals, value);
-    return buf;
+    size_t needed_size = std::snprintf(nullptr, 0, "%.*f", decimals, value);
+    std::string res(needed_size, '\0');
+    std::snprintf(&res.front(), res.size(), "%.*f", decimals, value);
+    return res;
 }
 
 const float GLGizmoRotate::Offset = 5.0f;
@@ -1770,5 +1787,237 @@ std::string GLGizmoSlaSupports::on_get_name() const
     return L("SLA Support Points");
 }
 
+
+
+// GLGizmoCut
+
+class GLGizmoCutPanel : public wxPanel
+{
+public:
+    GLGizmoCutPanel(wxWindow *parent);
+
+    void display(bool display);
+private:
+    bool m_active;
+    wxCheckBox *m_cb_rotate;
+    wxButton *m_btn_cut;
+    wxButton *m_btn_cancel;
+};
+
+GLGizmoCutPanel::GLGizmoCutPanel(wxWindow *parent)
+    : wxPanel(parent)
+    , m_active(false)
+    , m_cb_rotate(new wxCheckBox(this, wxID_ANY, _(L("Rotate lower part upwards"))))
+    , m_btn_cut(new wxButton(this, wxID_OK, _(L("Perform cut"))))
+    , m_btn_cancel(new wxButton(this, wxID_CANCEL, _(L("Cancel"))))
+{
+    enum { MARGIN = 5 };
+
+    auto *sizer = new wxBoxSizer(wxHORIZONTAL);
+
+    auto *label = new wxStaticText(this, wxID_ANY, _(L("Cut object:")));
+    sizer->Add(label, 0, wxALL | wxALIGN_CENTER, MARGIN);
+    sizer->Add(m_cb_rotate, 0, wxALL | wxALIGN_CENTER, MARGIN);
+    sizer->AddStretchSpacer();
+    sizer->Add(m_btn_cut, 0, wxALL | wxALIGN_CENTER, MARGIN);
+    sizer->Add(m_btn_cancel, 0, wxALL | wxALIGN_CENTER, MARGIN);
+
+    SetSizer(sizer);
+}
+
+void GLGizmoCutPanel::display(bool display)
+{
+    Show(display);
+    GetParent()->Layout();
+}
+
+
+const double GLGizmoCut::Offset = 10.0;
+const double GLGizmoCut::Margin = 20.0;
+const std::array<float, 3> GLGizmoCut::GrabberColor = { 1.0, 0.5, 0.0 };
+
+GLGizmoCut::GLGizmoCut(GLCanvas3D& parent)
+    : GLGizmoBase(parent)
+    , m_cut_z(0.0)
+    , m_panel(nullptr)
+{}
+
+void GLGizmoCut::create_external_gizmo_widgets(wxWindow *parent)
+{
+    wxASSERT(m_panel == nullptr);
+
+    m_panel = new GLGizmoCutPanel(parent);
+    parent->GetSizer()->Add(m_panel, 0, wxEXPAND);
+
+    parent->Layout();
+    parent->Fit();
+    auto prev_heigh = parent->GetMinSize().GetHeight();
+    parent->SetMinSize(wxSize(-1, std::max(prev_heigh, m_panel->GetSize().GetHeight())));
+
+    m_panel->Hide();
+    m_panel->Bind(wxEVT_BUTTON, [this](wxCommandEvent&) {
+        perform_cut();
+    }, wxID_OK);
+}
+
+bool GLGizmoCut::on_init()
+{
+    // TODO: icon
+
+    std::string path = resources_dir() + "/icons/overlay/";
+
+    if (!m_textures[Off].load_from_file(path + "cut_off.png", false)) {
+        return false;
+    }
+
+    if (!m_textures[Hover].load_from_file(path + "cut_hover.png", false)) {
+        return false;
+    }
+
+    if (!m_textures[On].load_from_file(path + "cut_on.png", false)) {
+        return false;
+    }
+
+    m_grabbers.emplace_back();
+
+    return true;
+}
+
+std::string GLGizmoCut::on_get_name() const
+{
+    return L("Cut");
+}
+
+void GLGizmoCut::on_set_state()
+{
+    // Reset m_cut_z on gizmo activation
+    if (get_state() == On) {
+        m_cut_z = 0.0;
+    }
+
+    // Display or hide the extra panel
+    if (m_panel != nullptr) {
+        m_panel->display(get_state() == On);
+    }
+}
+
+bool GLGizmoCut::on_is_activable(const GLCanvas3D::Selection& selection) const
+{
+    return selection.is_single_full_instance() && !selection.is_wipe_tower();
+}
+
+void GLGizmoCut::on_start_dragging(const GLCanvas3D::Selection& selection)
+{
+    if (m_hover_id == -1) { return; }
+
+    const BoundingBoxf3& box = selection.get_bounding_box();
+    m_start_z = m_cut_z;
+    m_max_z = box.size()(2) / 2.0;
+    m_drag_pos = m_grabbers[m_hover_id].center;
+    m_drag_center = box.center();
+    m_drag_center(2) += m_cut_z;
+}
+
+void GLGizmoCut::on_update(const UpdateData& data)
+{
+    if (m_hover_id != -1) {
+        // Clamp the plane to the object's bounding box
+        const double new_z = m_start_z + calc_projection(data.mouse_ray);
+        m_cut_z = std::max(-m_max_z, std::min(m_max_z, new_z));
+    }
+}
+
+void GLGizmoCut::on_render(const GLCanvas3D::Selection& selection) const
+{
+    if (m_grabbers[0].dragging) {
+        set_tooltip("Z: " + format(m_cut_z, 2));
+    }
+
+    const BoundingBoxf3& box = selection.get_bounding_box();
+    Vec3d plane_center = box.center();
+    plane_center(2) += m_cut_z;
+
+    const float min_x = box.min(0) - Margin;
+    const float max_x = box.max(0) + Margin;
+    const float min_y = box.min(1) - Margin;
+    const float max_y = box.max(1) + Margin;
+    ::glEnable(GL_DEPTH_TEST);
+    ::glDisable(GL_CULL_FACE);
+    ::glEnable(GL_BLEND);
+    ::glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA);
+
+    // Draw the cutting plane
+    ::glBegin(GL_QUADS);
+    ::glColor4f(0.8f, 0.8f, 0.8f, 0.5f);
+    ::glVertex3f(min_x, min_y, plane_center(2));
+    ::glVertex3f(max_x, min_y, plane_center(2));
+    ::glVertex3f(max_x, max_y, plane_center(2));
+    ::glVertex3f(min_x, max_y, plane_center(2));
+    ::glEnd();
+
+    ::glEnable(GL_CULL_FACE);
+    ::glDisable(GL_BLEND);
+
+    // TODO: draw cut part contour?
+
+    // Draw the grabber and the connecting line
+    m_grabbers[0].center = plane_center;
+    m_grabbers[0].center(2) = plane_center(2) + Offset;
+
+    ::glDisable(GL_DEPTH_TEST);
+    ::glLineWidth(m_hover_id != -1 ? 2.0f : 1.5f);
+    ::glColor3f(1.0, 1.0, 0.0);
+    ::glBegin(GL_LINES);
+    ::glVertex3dv(plane_center.data());
+    ::glVertex3dv(m_grabbers[0].center.data());
+    ::glEnd();
+
+    std::copy(std::begin(GrabberColor), std::end(GrabberColor), m_grabbers[0].color);
+    m_grabbers[0].render(m_hover_id == 0, box.max_size());
+}
+
+void GLGizmoCut::on_render_for_picking(const GLCanvas3D::Selection& selection) const
+{
+    ::glDisable(GL_DEPTH_TEST);
+
+    render_grabbers_for_picking(selection.get_bounding_box());
+}
+
+void GLGizmoCut::perform_cut()
+{
+    const auto &selection = m_parent.get_selection();
+
+    const auto instance_idx = selection.get_instance_idx();
+    const auto object_idx = selection.get_object_idx();
+
+    wxCHECK_RET(instance_idx >= 0 && object_idx >= 0, "GLGizmoCut: Invalid object selection");
+
+    wxGetApp().plater()->cut(object_idx, instance_idx, m_cut_z);
+}
+
+double GLGizmoCut::calc_projection(const Linef3& mouse_ray) const
+{
+    double projection = 0.0;
+
+    const Vec3d starting_vec = m_drag_pos - m_drag_center;
+    const double len_starting_vec = starting_vec.norm();
+    if (len_starting_vec != 0.0)
+    {
+        Vec3d mouse_dir = mouse_ray.unit_vector();
+        // finds the intersection of the mouse ray with the plane parallel to the camera viewport and passing throught the starting position
+        // use ray-plane intersection see i.e. https://en.wikipedia.org/wiki/Line%E2%80%93plane_intersection algebric form
+        // in our case plane normal and ray direction are the same (orthogonal view)
+        // when moving to perspective camera the negative z unit axis of the camera needs to be transformed in world space and used as plane normal
+        Vec3d inters = mouse_ray.a + (m_drag_pos - mouse_ray.a).dot(mouse_dir) / mouse_dir.squaredNorm() * mouse_dir;
+        // vector from the starting position to the found intersection
+        Vec3d inters_vec = inters - m_drag_pos;
+
+        // finds projection of the vector along the staring direction
+        projection = inters_vec.dot(starting_vec.normalized());
+    }
+    return projection;
+}
+
+
 } // namespace GUI
 } // namespace Slic3r
diff --git a/src/slic3r/GUI/GLGizmo.hpp b/src/slic3r/GUI/GLGizmo.hpp
index eac9693bcb..376c286904 100644
--- a/src/slic3r/GUI/GLGizmo.hpp
+++ b/src/slic3r/GUI/GLGizmo.hpp
@@ -6,7 +6,13 @@
 #include "../../libslic3r/Point.hpp"
 #include "../../libslic3r/BoundingBox.hpp"
 
+#include <array>
 #include <vector>
+#include <memory>
+
+
+class wxWindow;
+
 
 namespace Slic3r {
 
@@ -120,6 +126,8 @@ public:
     void render(const GLCanvas3D::Selection& selection) const { on_render(selection); }
     void render_for_picking(const GLCanvas3D::Selection& selection) const { on_render_for_picking(selection); }
 
+    virtual void create_external_gizmo_widgets(wxWindow *parent);
+
 protected:
     virtual bool on_init() = 0;
     virtual std::string on_get_name() const = 0;
@@ -450,6 +458,43 @@ protected:
     bool on_is_activable(const GLCanvas3D::Selection& selection) const override;
 };
 
+
+class GLGizmoCutPanel;
+
+class GLGizmoCut : public GLGizmoBase
+{
+    static const double Offset;
+    static const double Margin;
+    static const std::array<float, 3> GrabberColor;
+
+    double m_cut_z;
+    double m_start_z;
+    double m_max_z;
+    Vec3d m_drag_pos;
+    Vec3d m_drag_center;
+    GLGizmoCutPanel *m_panel;
+
+public:
+    explicit GLGizmoCut(GLCanvas3D& parent);
+
+    virtual void create_external_gizmo_widgets(wxWindow *parent);
+
+protected:
+    virtual bool on_init();
+    virtual std::string on_get_name() const;
+    virtual void on_set_state();
+    virtual bool on_is_activable(const GLCanvas3D::Selection& selection) const;
+    virtual void on_start_dragging(const GLCanvas3D::Selection& selection);
+    virtual void on_update(const UpdateData& data);
+    virtual void on_render(const GLCanvas3D::Selection& selection) const;
+    virtual void on_render_for_picking(const GLCanvas3D::Selection& selection) const;
+
+private:
+    void perform_cut();
+    double calc_projection(const Linef3& mouse_ray) const;
+};
+
+
 } // namespace GUI
 } // namespace Slic3r
 
diff --git a/src/slic3r/GUI/GLToolbar.cpp b/src/slic3r/GUI/GLToolbar.cpp
index 26ca4a4dca..0e99f88ff8 100644
--- a/src/slic3r/GUI/GLToolbar.cpp
+++ b/src/slic3r/GUI/GLToolbar.cpp
@@ -24,7 +24,6 @@ wxDEFINE_EVENT(EVT_GLTOOLBAR_MORE, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLTOOLBAR_FEWER, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLTOOLBAR_SPLIT_OBJECTS, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLTOOLBAR_SPLIT_VOLUMES, SimpleEvent);
-wxDEFINE_EVENT(EVT_GLTOOLBAR_CUT, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLTOOLBAR_LAYERSEDITING, SimpleEvent);
 
 
diff --git a/src/slic3r/GUI/GLToolbar.hpp b/src/slic3r/GUI/GLToolbar.hpp
index 6669bc9664..dde62c6452 100644
--- a/src/slic3r/GUI/GLToolbar.hpp
+++ b/src/slic3r/GUI/GLToolbar.hpp
@@ -24,7 +24,6 @@ wxDECLARE_EVENT(EVT_GLTOOLBAR_MORE, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLTOOLBAR_FEWER, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLTOOLBAR_SPLIT_OBJECTS, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLTOOLBAR_SPLIT_VOLUMES, SimpleEvent);
-wxDECLARE_EVENT(EVT_GLTOOLBAR_CUT, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLTOOLBAR_LAYERSEDITING, SimpleEvent);
 
 class GLToolbarItem
diff --git a/src/slic3r/GUI/GUI_Utils.cpp b/src/slic3r/GUI/GUI_Utils.cpp
index c9fa96f4c6..43b3c38f71 100644
--- a/src/slic3r/GUI/GUI_Utils.cpp
+++ b/src/slic3r/GUI/GUI_Utils.cpp
@@ -15,6 +15,18 @@ namespace Slic3r {
 namespace GUI {
 
 
+wxTopLevelWindow* find_toplevel_parent(wxWindow *window)
+{
+    for (; window != nullptr; window = window->GetParent()) {
+        if (window->IsTopLevel()) {
+            return dynamic_cast<wxTopLevelWindow*>(window);
+        }
+    }
+
+    return nullptr;
+}
+
+
 CheckboxFileDialog::ExtraPanel::ExtraPanel(wxWindow *parent)
     : wxPanel(parent, wxID_ANY)
 {
diff --git a/src/slic3r/GUI/GUI_Utils.hpp b/src/slic3r/GUI/GUI_Utils.hpp
index fe96e5a1b8..9cee986b0c 100644
--- a/src/slic3r/GUI/GUI_Utils.hpp
+++ b/src/slic3r/GUI/GUI_Utils.hpp
@@ -6,6 +6,7 @@
 
 #include <boost/optional.hpp>
 
+#include <wx/event.h>
 #include <wx/filedlg.h>
 #include <wx/gdicmn.h>
 #include <wx/panel.h>
@@ -19,6 +20,48 @@ namespace Slic3r {
 namespace GUI {
 
 
+wxTopLevelWindow* find_toplevel_parent(wxWindow *window);
+
+
+class EventGuard
+{
+public:
+    EventGuard() {}
+    EventGuard(const EventGuard&) = delete;
+    EventGuard(EventGuard &&other) : unbinder(std::move(other.unbinder)) {}
+
+    ~EventGuard() {
+        if (unbinder) {
+            unbinder(false);
+        }
+    }
+
+    template<class EvTag, class Fun> void bind(wxEvtHandler *emitter, const EvTag &type, Fun fun)
+    {
+        // This is a way to type-erase both the event type as well as the handler:
+
+        unbinder = std::move([=](bool bind) {
+            if (bind) {
+                emitter->Bind(type, fun);
+            } else {
+                emitter->Unbind(type, fun);
+            }
+        });
+
+        unbinder(true);
+    }
+
+    EventGuard& operator=(const EventGuard&) = delete;
+    EventGuard& operator=(EventGuard &&other)
+    {
+        unbinder.swap(other.unbinder);
+        return *this;
+    }
+private:
+    std::function<void(bool)> unbinder;
+};
+
+
 class CheckboxFileDialog : public wxFileDialog
 {
 public:
diff --git a/src/slic3r/GUI/MainFrame.cpp b/src/slic3r/GUI/MainFrame.cpp
index c5883dcf52..85ac442f71 100644
--- a/src/slic3r/GUI/MainFrame.cpp
+++ b/src/slic3r/GUI/MainFrame.cpp
@@ -7,6 +7,7 @@
 #include <wx/menu.h>
 #include <wx/progdlg.h>
 #include <wx/tooltip.h>
+#include <wx/glcanvas.h>
 #include <wx/debug.h>
 
 #include "Tab.hpp"
@@ -100,7 +101,6 @@ wxFrame(NULL, wxID_ANY, SLIC3R_BUILD, wxDefaultPosition, wxDefaultSize, wxDEFAUL
     });
 
     update_ui_from_settings();
-    return;
 }
 
 void MainFrame::init_tabpanel()
diff --git a/src/slic3r/GUI/MainFrame.hpp b/src/slic3r/GUI/MainFrame.hpp
index 7722d0b65f..b324586c45 100644
--- a/src/slic3r/GUI/MainFrame.hpp
+++ b/src/slic3r/GUI/MainFrame.hpp
@@ -81,6 +81,7 @@ public:
     MainFrame(const bool no_plater, const bool loaded);
     ~MainFrame() {}
 
+    Plater*     plater() { return m_plater; }
 
     void        init_tabpanel();
     const std::map<std::string, Tab*>& options_tabs() const { return m_options_tabs; }
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index 7768df7dd5..cb0e04e37c 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -20,7 +20,8 @@
 #include <wx/progdlg.h>
 #include <wx/wupdlock.h>
 #include <wx/colordlg.h>
-#include <wx/numdlg.h> 
+#include <wx/numdlg.h>
+#include <wx/debug.h>
 
 #include "libslic3r/libslic3r.h"
 #include "libslic3r/PrintConfig.hpp"
@@ -881,6 +882,7 @@ struct Plater::priv
     // GUI elements
     wxNotebook *notebook;
     Sidebar *sidebar;
+    wxWindow *panel3d;
     wxGLCanvas *canvas3D;    // TODO: Use GLCanvas3D when we can
     Preview *preview;
 
@@ -959,7 +961,6 @@ struct Plater::priv
     void on_action_add(SimpleEvent&);
     void on_action_split_objects(SimpleEvent&);
     void on_action_split_volumes(SimpleEvent&);
-    void on_action_cut(SimpleEvent&);
     void on_action_layersediting(SimpleEvent&);
 
     void on_object_select(SimpleEvent&);
@@ -978,7 +979,6 @@ private:
     bool can_decrease_instances() const;
     bool can_split_to_objects() const;
     bool can_split_to_volumes() const;
-    bool can_cut_object() const;
     bool layers_height_allowed() const;
     bool can_delete_all() const;
     bool can_arrange() const;
@@ -988,19 +988,20 @@ private:
 const std::regex Plater::priv::pattern_bundle(".*[.](amf|amf[.]xml|zip[.]amf|3mf|prusa)", std::regex::icase);
 const std::regex Plater::priv::pattern_3mf(".*3mf", std::regex::icase);
 const std::regex Plater::priv::pattern_zip_amf(".*[.]zip[.]amf", std::regex::icase);
-Plater::priv::priv(Plater *q, MainFrame *main_frame) :
-    q(q),
-    main_frame(main_frame),
-    config(Slic3r::DynamicPrintConfig::new_from_defaults_keys({
+Plater::priv::priv(Plater *q, MainFrame *main_frame)
+    : q(q)
+    , main_frame(main_frame)
+    , config(Slic3r::DynamicPrintConfig::new_from_defaults_keys({
         "bed_shape", "complete_objects", "extruder_clearance_radius", "skirts", "skirt_distance",
         "brim_width", "variable_layer_height", "serial_port", "serial_speed", "host_type", "print_host",
         "printhost_apikey", "printhost_cafile", "nozzle_diameter", "single_extruder_multi_material",
         "wipe_tower", "wipe_tower_x", "wipe_tower_y", "wipe_tower_width", "wipe_tower_rotation_angle",
-		"extruder_colour", "filament_colour", "max_print_height", "printer_model", "printer_technology"
-    })),
-    notebook(new wxNotebook(q, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxNB_BOTTOM)),
-    sidebar(new Sidebar(q)),
-    canvas3D(GLCanvas3DManager::create_wxglcanvas(notebook))
+        "extruder_colour", "filament_colour", "max_print_height", "printer_model", "printer_technology"
+        }))
+    , notebook(new wxNotebook(q, wxID_ANY, wxDefaultPosition, wxDefaultSize, wxNB_BOTTOM))
+    , sidebar(new Sidebar(q))
+    , panel3d(new wxWindow(notebook, wxID_ANY))
+    , canvas3D(GLCanvas3DManager::create_wxglcanvas(panel3d))
 #if ENABLE_NEW_MENU_LAYOUT
     , project_filename(wxEmptyString)
 #endif // ENABLE_NEW_MENU_LAYOUT
@@ -1027,9 +1028,19 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame) :
 
     _3DScene::add_canvas(canvas3D);
     _3DScene::allow_multisample(canvas3D, GLCanvas3DManager::can_multisample());
-    notebook->AddPage(canvas3D, _(L("3D")));
+
+    auto *panel3dsizer = new wxBoxSizer(wxVERTICAL);
+    panel3dsizer->Add(canvas3D, 1, wxEXPAND);
+    auto *panel_gizmo_widgets = new wxPanel(panel3d, wxID_ANY);
+    panel_gizmo_widgets->SetSizer(new wxBoxSizer(wxVERTICAL));
+    panel3dsizer->Add(panel_gizmo_widgets, 0, wxEXPAND);
+
+    panel3d->SetSizer(panel3dsizer);
+    notebook->AddPage(panel3d, _(L("3D")));
     preview = new GUI::Preview(notebook, config, &print, &gcode_preview_data, [this](){ schedule_background_process(); });
 
+    _3DScene::get_canvas(canvas3D)->set_external_gizmo_widgets_parent(panel_gizmo_widgets);
+
     // XXX: If have OpenGL
     _3DScene::enable_picking(canvas3D, true);
     _3DScene::enable_moving(canvas3D, true);
@@ -1092,7 +1103,6 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame) :
     canvas3D->Bind(EVT_GLTOOLBAR_FEWER, [q](SimpleEvent&) { q->decrease_instances(); });
     canvas3D->Bind(EVT_GLTOOLBAR_SPLIT_OBJECTS, &priv::on_action_split_objects, this);
     canvas3D->Bind(EVT_GLTOOLBAR_SPLIT_VOLUMES, &priv::on_action_split_volumes, this);
-    canvas3D->Bind(EVT_GLTOOLBAR_CUT, &priv::on_action_cut, this);
     canvas3D->Bind(EVT_GLTOOLBAR_LAYERSEDITING, &priv::on_action_layersediting, this);
 
     // Preview events:
@@ -1475,7 +1485,6 @@ void Plater::priv::selection_changed()
     _3DScene::enable_toolbar_item(canvas3D, "fewer", can_decrease_instances());
     _3DScene::enable_toolbar_item(canvas3D, "splitobjects", can_split_to_objects());
     _3DScene::enable_toolbar_item(canvas3D, "splitvolumes", can_split_to_volumes());
-    _3DScene::enable_toolbar_item(canvas3D, "cut", can_cut_object());
     _3DScene::enable_toolbar_item(canvas3D, "layersediting", layers_height_allowed());
     // forces a frame render to update the view (to avoid a missed update if, for example, the context menu appears)
     _3DScene::render(canvas3D);
@@ -1970,11 +1979,6 @@ void Plater::priv::on_action_split_volumes(SimpleEvent&)
     split_volume();
 }
 
-void Plater::priv::on_action_cut(SimpleEvent&)
-{
-    // TODO
-}
-
 void Plater::priv::on_action_layersediting(SimpleEvent&)
 {
     bool enable = !_3DScene::is_layers_editing_enabled(canvas3D);
@@ -2114,12 +2118,6 @@ bool Plater::priv::can_split_to_volumes() const
     return (0 <= obj_idx) && (obj_idx < (int)model.objects.size()) && !model.objects[obj_idx]->is_multiparts();
 }
 
-bool Plater::priv::can_cut_object() const
-{
-    int obj_idx = get_selected_object_idx();
-    return (0 <= obj_idx) && (obj_idx < (int)model.objects.size());
-}
-
 bool Plater::priv::layers_height_allowed() const
 {
     int obj_idx = get_selected_object_idx();
@@ -2313,6 +2311,21 @@ void Plater::set_number_of_copies(/*size_t num*/)
         decrease_instances(-diff);
 }
 
+void Plater::cut(size_t obj_idx, size_t instance_idx, coordf_t z)
+{
+    wxCHECK_RET(obj_idx < p->model.objects.size(), "obj_idx out of bounds");
+    auto *object = p->model.objects[obj_idx];
+
+    wxCHECK_RET(instance_idx < object->instances.size(), "instance_idx out of bounds");
+
+    const auto new_objects = object->cut(instance_idx, z);
+
+    remove(obj_idx);
+    p->load_model_objects(new_objects);
+
+    p->arrange();
+}
+
 void Plater::export_gcode(fs::path output_path)
 {
     if (p->model.objects.empty())
diff --git a/src/slic3r/GUI/Plater.hpp b/src/slic3r/GUI/Plater.hpp
index f23fbe72f3..d6716c620a 100644
--- a/src/slic3r/GUI/Plater.hpp
+++ b/src/slic3r/GUI/Plater.hpp
@@ -135,6 +135,8 @@ public:
     void decrease_instances(size_t num = 1);
     void set_number_of_copies(/*size_t num*/);
 
+    void cut(size_t obj_idx, size_t instance_idx, coordf_t z);
+
     // Note: empty path means "use the default"
     void export_gcode(boost::filesystem::path output_path = boost::filesystem::path());
     void export_stl();