diff --git a/src/slic3r/CMakeLists.txt b/src/slic3r/CMakeLists.txt
index 0b2dd67020..17b76e6296 100644
--- a/src/slic3r/CMakeLists.txt
+++ b/src/slic3r/CMakeLists.txt
@@ -136,8 +136,6 @@ set(SLIC3R_GUI_SOURCES
     GUI/ProgressStatusBar.cpp
     GUI/PrintHostDialogs.cpp
     GUI/PrintHostDialogs.hpp
-    GUI/ThumbnailGenerator.cpp
-    GUI/ThumbnailGenerator.hpp
     Utils/Http.cpp
     Utils/Http.hpp
     Utils/FixModelByWin10.cpp
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index c55d64b472..8d16187cb8 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -7,6 +7,9 @@
 #include "libslic3r/ClipperUtils.hpp"
 #include "libslic3r/PrintConfig.hpp"
 #include "libslic3r/GCode/PreviewData.hpp"
+#if ENABLE_THUMBNAIL_GENERATOR
+#include "libslic3r/GCode/ThumbnailData.hpp"
+#endif // ENABLE_THUMBNAIL_GENERATOR
 #include "libslic3r/Geometry.hpp"
 #include "libslic3r/ExtrusionEntity.hpp"
 #include "libslic3r/Utils.hpp"
@@ -1643,6 +1646,64 @@ void GLCanvas3D::render()
 #endif // ENABLE_RENDER_STATISTICS
 }
 
+#if ENABLE_THUMBNAIL_GENERATOR
+void GLCanvas3D::render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only)
+{
+    auto is_visible = [](const GLVolume& v) -> bool {
+        bool ret = v.printable;
+        ret &= (!v.shader_outside_printer_detection_enabled || !v.is_outside);
+        return ret;
+    };
+
+    static const float orange[] = { 0.99f, 0.49f, 0.26f };
+    static const float gray[] = { 0.64f, 0.64f, 0.64f };
+
+    thumbnail_data.set(w, h);
+
+    GLVolumePtrs visible_volumes;
+
+    for (GLVolume* vol : m_volumes.volumes)
+    {
+        if (!printable_only || is_visible(*vol))
+            visible_volumes.push_back(vol);
+    }
+
+    if (visible_volumes.empty())
+        return;
+
+    BoundingBoxf3 box;
+    for (const GLVolume* vol : visible_volumes)
+    {
+        box.merge(vol->transformed_bounding_box());
+    }
+
+    Camera camera;
+    camera.zoom_to_box(box, thumbnail_data.width, thumbnail_data.height);
+    camera.apply_viewport(0, 0, thumbnail_data.width, thumbnail_data.height);
+    camera.apply_view_matrix();
+    camera.apply_projection(box);
+
+    glsafe(::glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT));
+    glsafe(::glEnable(GL_LIGHTING));
+    glsafe(::glEnable(GL_DEPTH_TEST));
+
+    for (const GLVolume* vol : visible_volumes)
+    {
+        glsafe(::glColor3fv((vol->printable && !vol->is_outside) ? orange : gray));
+        vol->render();
+    }
+
+    glsafe(::glDisable(GL_DEPTH_TEST));
+    glsafe(::glDisable(GL_LIGHTING));
+    glsafe(::glReadPixels(0, 0, thumbnail_data.width, thumbnail_data.height, GL_RGBA, GL_UNSIGNED_BYTE, (void*)thumbnail_data.pixels.data()));
+
+    std::cout << "Generated thumbnail " << thumbnail_data.width << "x" << thumbnail_data.height << std::endl;
+
+    // force a frame render to restore the default framebuffer
+    render();
+}
+#endif // ENABLE_THUMBNAIL_GENERATOR
+
 void GLCanvas3D::select_all()
 {
     m_selection.add_all();
diff --git a/src/slic3r/GUI/GLCanvas3D.hpp b/src/slic3r/GUI/GLCanvas3D.hpp
index eb3c60bd16..611e9a932b 100644
--- a/src/slic3r/GUI/GLCanvas3D.hpp
+++ b/src/slic3r/GUI/GLCanvas3D.hpp
@@ -36,6 +36,9 @@ class GLShader;
 class ExPolygon;
 class BackgroundSlicingProcess;
 class GCodePreviewData;
+#if ENABLE_THUMBNAIL_GENERATOR
+struct ThumbnailData;
+#endif // ENABLE_THUMBNAIL_GENERATOR
 struct SlicingParameters;
 enum LayerHeightEditActionType : unsigned int;
 
@@ -446,10 +449,6 @@ public:
     wxGLCanvas* get_wxglcanvas() { return m_canvas; }
 	const wxGLCanvas* get_wxglcanvas() const { return m_canvas; }
 
-#if ENABLE_THUMBNAIL_GENERATOR
-    const GLVolumeCollection& get_volumes() const { return m_volumes; }
-#endif // ENABLE_THUMBNAIL_GENERATOR
-
     bool init();
     void post_event(wxEvent &&event);
 
@@ -523,6 +522,9 @@ public:
     bool is_dragging() const { return m_gizmos.is_dragging() || m_moving; }
 
     void render();
+#if ENABLE_THUMBNAIL_GENERATOR
+    void render_thumbnail(ThumbnailData& thumbnail_data, unsigned int w, unsigned int h, bool printable_only);
+#endif // ENABLE_THUMBNAIL_GENERATOR
 
     void select_all();
     void deselect_all();
diff --git a/src/slic3r/GUI/Plater.cpp b/src/slic3r/GUI/Plater.cpp
index f9167cec9f..0ebd208fa2 100644
--- a/src/slic3r/GUI/Plater.cpp
+++ b/src/slic3r/GUI/Plater.cpp
@@ -32,6 +32,9 @@
 #include "libslic3r/Format/AMF.hpp"
 #include "libslic3r/Format/3mf.hpp"
 #include "libslic3r/GCode/PreviewData.hpp"
+#if ENABLE_THUMBNAIL_GENERATOR
+#include "libslic3r/GCode/ThumbnailData.hpp"
+#endif // ENABLE_THUMBNAIL_GENERATOR
 #include "libslic3r/Model.hpp"
 #include "libslic3r/Polygon.hpp"
 #include "libslic3r/Print.hpp"
@@ -62,9 +65,6 @@
 #include "GUI_Preview.hpp"
 #include "3DBed.hpp"
 #include "Camera.hpp"
-#if ENABLE_THUMBNAIL_GENERATOR
-#include "ThumbnailGenerator.hpp"
-#endif // ENABLE_THUMBNAIL_GENERATOR
 #include "Tab.hpp"
 #include "PresetBundle.hpp"
 #include "BackgroundSlicingProcess.hpp"
@@ -1370,6 +1370,9 @@ struct Plater::priv
     Slic3r::Model               model;
     PrinterTechnology           printer_technology = ptFFF;
     Slic3r::GCodePreviewData    gcode_preview_data;
+#if ENABLE_THUMBNAIL_GENERATOR
+    Slic3r::ThumbnailData       thumbnail_data;
+#endif // ENABLE_THUMBNAIL_GENERATOR
 
     // GUI elements
     wxSizer* panel_sizer{ nullptr };
@@ -1381,9 +1384,6 @@ struct Plater::priv
     View3D* view3D;
     GLToolbar view_toolbar;
     Preview *preview;
-#if ENABLE_THUMBNAIL_GENERATOR
-    ThumbnailGenerator thumbnail_generator;
-#endif // ENABLE_THUMBNAIL_GENERATOR
 
     BackgroundSlicingProcess    background_process;
     bool suppressed_backround_processing_update { false };
@@ -1999,7 +1999,7 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame)
     background_process.set_sla_print(&sla_print);
     background_process.set_gcode_preview_data(&gcode_preview_data);
 #if ENABLE_THUMBNAIL_GENERATOR
-    background_process.set_thumbnail_data(&thumbnail_generator.get_data());
+    background_process.set_thumbnail_data(&thumbnail_data);
 #endif // ENABLE_THUMBNAIL_GENERATOR
     background_process.set_slicing_completed_event(EVT_SLICING_COMPLETED);
     background_process.set_finished_event(EVT_PROCESS_COMPLETED);
@@ -3627,7 +3627,7 @@ bool Plater::priv::init_object_menu()
 #if ENABLE_THUMBNAIL_GENERATOR
 void Plater::priv::generate_thumbnail(unsigned int w, unsigned int h, bool printable_only)
 {
-    thumbnail_generator.generate(view3D->get_canvas3d()->get_volumes().volumes, w, h, printable_only);
+    view3D->get_canvas3d()->render_thumbnail(thumbnail_data, w, h, printable_only);
 }
 #endif // ENABLE_THUMBNAIL_GENERATOR
 
@@ -4671,7 +4671,7 @@ void Plater::export_3mf(const boost::filesystem::path& output_path)
     wxBusyCursor wait;
 #if ENABLE_THUMBNAIL_GENERATOR
     p->generate_thumbnail(THUMBNAIL_SIZE_3MF.first, THUMBNAIL_SIZE_3MF.second, false);
-    if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr, &p->thumbnail_generator.get_data())) {
+    if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr, &p->thumbnail_data)) {
 #else
     if (Slic3r::store_3mf(path_u8.c_str(), &p->model, export_config ? &cfg : nullptr)) {
 #endif // ENABLE_THUMBNAIL_GENERATOR
@@ -5171,13 +5171,6 @@ void Plater::paste_from_clipboard()
     p->view3D->get_canvas3d()->get_selection().paste_from_clipboard();
 }
 
-#if ENABLE_THUMBNAIL_GENERATOR
-void Plater::generate_thumbnail(unsigned int w, unsigned int h, bool printable_only)
-{
-    p->generate_thumbnail(w, h, printable_only);
-}
-#endif // ENABLE_THUMBNAIL_GENERATOR
-
 void Plater::msw_rescale()
 {
     p->preview->msw_rescale();
diff --git a/src/slic3r/GUI/Plater.hpp b/src/slic3r/GUI/Plater.hpp
index 7c671f6695..00ceb89bc3 100644
--- a/src/slic3r/GUI/Plater.hpp
+++ b/src/slic3r/GUI/Plater.hpp
@@ -240,10 +240,6 @@ public:
     void copy_selection_to_clipboard();
     void paste_from_clipboard();
 
-#if ENABLE_THUMBNAIL_GENERATOR
-    void generate_thumbnail(unsigned int w, unsigned int h, bool printable_only);
-#endif // ENABLE_THUMBNAIL_GENERATOR
-
     bool can_delete() const;
     bool can_delete_all() const;
     bool can_increase_instances() const;