diff --git a/sandboxes/opencsg/CMakeLists.txt b/sandboxes/opencsg/CMakeLists.txt
index 9a216a7dc..651fbe82f 100644
--- a/sandboxes/opencsg/CMakeLists.txt
+++ b/sandboxes/opencsg/CMakeLists.txt
@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.0)
 
 project(OpenCSG-example)
 
-add_executable(opencsg_example main.cpp  GLScene.hpp GLScene.cpp Canvas.hpp 
+add_executable(opencsg_example main.cpp  GLScene.hpp GLScene.cpp 
     ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/ProgressStatusBar.cpp
     ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/I18N.hpp
     ${CMAKE_CURRENT_SOURCE_DIR}/../../src/slic3r/GUI/I18N.cpp)
diff --git a/sandboxes/opencsg/Canvas.hpp b/sandboxes/opencsg/Canvas.hpp
deleted file mode 100644
index 424579945..000000000
--- a/sandboxes/opencsg/Canvas.hpp
+++ /dev/null
@@ -1,48 +0,0 @@
-#ifndef CANVAS_HPP
-#define CANVAS_HPP
-
-#include <memory>
-
-// For compilers that support precompilation, includes "wx/wx.h".
-#include <wx/wxprec.h>
-#ifndef WX_PRECOMP
-#include <wx/wx.h>
-#endif
-
-#include <wx/glcanvas.h>
-#include <wx/msgdlg.h>
-
-#include "GLScene.hpp"
-
-namespace Slic3r { namespace GL {
-
-class Canvas: public wxGLCanvas, public Slic3r::GL::Display
-{
-    std::unique_ptr<wxGLContext> m_context;
-public:
-    
-    void set_active(long w, long h) override
-    {
-        SetCurrent(*m_context);
-        Slic3r::GL::Display::set_active(w, h);
-    }
-    
-    void swap_buffers() override { SwapBuffers(); }
-        
-    template<class...Args>
-    Canvas(Args &&...args): wxGLCanvas(std::forward<Args>(args)...)
-    {
-        auto ctx = new wxGLContext(this);
-        if (!ctx || !ctx->IsOK()) {
-            wxMessageBox("Could not create OpenGL context.", "Error",
-                         wxOK | wxICON_ERROR);
-            return;
-        }
-        
-        m_context.reset(ctx);
-    }
-};
-
-}} // namespace Slic3r::GL
-
-#endif // CANVAS_HPP
diff --git a/sandboxes/opencsg/GLScene.hpp b/sandboxes/opencsg/GLScene.hpp
index 5a4afb396..68cc59b01 100644
--- a/sandboxes/opencsg/GLScene.hpp
+++ b/sandboxes/opencsg/GLScene.hpp
@@ -21,16 +21,16 @@ template<class T> using uqptr = std::unique_ptr<T>;
 template<class T> using wkptr = std::weak_ptr<T>;
 
 template<class T, class A = std::allocator<T>>
-using Collection = std::vector<T, A>;
+using vector = std::vector<T, A>;
 
-template<class L> void cleanup(Collection<std::weak_ptr<L>> &listeners) {
+template<class L> void cleanup(vector<std::weak_ptr<L>> &listeners) {
     auto it = std::remove_if(listeners.begin(), listeners.end(),
                              [](auto &l) { return !l.lock(); });
     listeners.erase(it, listeners.end());
 }
 
 template<class F, class L, class...Args>
-void call(F &&f, Collection<std::weak_ptr<L>> &listeners, Args&&... args) {
+void call(F &&f, vector<std::weak_ptr<L>> &listeners, Args&&... args) {
     for (auto &l : listeners)
         if (auto p = l.lock()) ((p.get())->*f)(std::forward<Args>(args)...);
 }
@@ -57,7 +57,7 @@ public:
     };
     
 private:
-    Collection<wkptr<Listener>> m_listeners;
+    vector<wkptr<Listener>> m_listeners;
         
 public:
     virtual ~MouseInput() = default;
@@ -104,9 +104,9 @@ public:
 
     // Vertices and their normals, interleaved to be used by void
     // glInterleavedArrays(GL_N3F_V3F, 0, x)
-    Collection<float> vertices_and_normals_interleaved;
-    Collection<int>   triangle_indices;
-    Collection<int>   quad_indices;
+    vector<float> vertices_and_normals_interleaved;
+    vector<int>   triangle_indices;
+    vector<int>   quad_indices;
 
     // When the geometry data is loaded into the graphics card as Vertex
     // Buffer Objects, the above mentioned std::vectors are cleared and the
@@ -271,7 +271,7 @@ public:
     }
     
 private:
-    Collection<wkptr<Listener>> m_listeners;
+    vector<wkptr<Listener>> m_listeners;
 };
 
 class Display : public Scene::Listener
@@ -283,9 +283,9 @@ protected:
     CSGSettings m_csgsettings;
     
     struct SceneCache {
-        Collection<shptr<Primitive>> primitives;
-        Collection<Primitive *> primitives_free;
-        Collection<OpenCSG::Primitive *> primitives_csg;
+        vector<shptr<Primitive>> primitives;
+        vector<Primitive *> primitives_free;
+        vector<OpenCSG::Primitive *> primitives_csg;
         
         void clear();
         
@@ -332,8 +332,9 @@ class Controller : public std::enable_shared_from_this<Controller>,
     bool m_left_btn = false, m_right_btn = false;
 
     shptr<Scene>               m_scene;
-    Collection<wkptr<Display>> m_displays;
+    vector<wkptr<Display>> m_displays;
     
+    // Call a method of Camera on all the cameras of the attached displays
     template<class F, class...Args>
     void call_cameras(F &&f, Args&&... args) {
         for (wkptr<Display> &l : m_displays)
diff --git a/sandboxes/opencsg/main.cpp b/sandboxes/opencsg/main.cpp
index d01687428..c2f8a74aa 100644
--- a/sandboxes/opencsg/main.cpp
+++ b/sandboxes/opencsg/main.cpp
@@ -15,9 +15,9 @@
 #include <wx/tglbtn.h>
 #include <wx/combobox.h>
 #include <wx/spinctrl.h>
+#include <wx/msgdlg.h>
 #include <wx/glcanvas.h>
 
-#include "Canvas.hpp"
 #include "GLScene.hpp"
 
 #include "libslic3r/Model.hpp"
@@ -29,6 +29,33 @@
 
 using namespace Slic3r::GL;
 
+class Canvas: public wxGLCanvas, public Slic3r::GL::Display
+{
+    std::unique_ptr<wxGLContext> m_context;
+public:
+    
+    void set_active(long w, long h) override
+    {
+        SetCurrent(*m_context);
+        Slic3r::GL::Display::set_active(w, h);
+    }
+    
+    void swap_buffers() override { SwapBuffers(); }
+    
+    template<class...Args>
+    Canvas(Args &&...args): wxGLCanvas(std::forward<Args>(args)...)
+    {
+        auto ctx = new wxGLContext(this);
+        if (!ctx || !ctx->IsOK()) {
+            wxMessageBox("Could not create OpenGL context.", "Error",
+                         wxOK | wxICON_ERROR);
+            return;
+        }
+        
+        m_context.reset(ctx);
+    }
+};
+
 class MyFrame: public wxFrame
 {
     shptr<Scene>      m_scene;    // Model