diff --git a/applications/Mapple/paint_canvas.cpp b/applications/Mapple/paint_canvas.cpp
index c7e59a2d..e01fc06e 100644
--- a/applications/Mapple/paint_canvas.cpp
+++ b/applications/Mapple/paint_canvas.cpp
@@ -1878,17 +1878,24 @@ void PaintCanvas::showCoordinatesUnderMouse(bool b) {
 
 
 void PaintCanvas::draw() {
-    // To have split views of different rendering styles for the same object/scene.
-    //glEnable(GL_SCISSOR_TEST);
-    //int scissor[4];
-    //glGetIntegerv(GL_SCISSOR_BOX, scissor);
-    //glScissor(scissor[0], scissor[1], scissor[2] * 0.5f, scissor[3]);
-    //current_model()->renderer()->get_lines_drawable("edges")->set_visible(false);
-    //Viewer::draw();
-    //glScissor(scissor[2] * 0.5f, scissor[1], scissor[2] * 0.5f, scissor[3]);
-    //current_model()->renderer()->get_lines_drawable("edges")->set_visible(true);
-    //Viewer::draw();
-    //glScissor(scissor[0], scissor[1], scissor[2], scissor[3]);
+#if 0
+    // Example code: split the view to have different rendering styles for the same object/scene.
+    glEnable(GL_SCISSOR_TEST);
+    int viewport[4];
+    glGetIntegerv(GL_VIEWPORT, viewport);
+    glScissor(viewport[0], viewport[1], viewport[2] * 0.5f, viewport[3]);
+    for (const auto m : models_) {
+        for (auto d : m->renderer()->triangles_drawables())
+            d->draw(camera());
+    }
+    glScissor(viewport[2] * 0.5f, viewport[1], viewport[2] * 0.5f, viewport[3]);
+    for (const auto m : models_) {
+        for (auto d : m->renderer()->lines_drawables())
+            d->draw(camera());
+    }
+    glScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
+
+#else 
 
     if (models_.empty())
         return;
@@ -1965,4 +1972,5 @@ void PaintCanvas::draw() {
 
     if (edl())
         edl()->end();
+#endif
 }
diff --git a/easy3d/viewer/viewer.cpp b/easy3d/viewer/viewer.cpp
index c745390c..dc673064 100644
--- a/easy3d/viewer/viewer.cpp
+++ b/easy3d/viewer/viewer.cpp
@@ -1729,17 +1729,24 @@ namespace easy3d {
 
 
     void Viewer::draw() const {
-        // To have split views of different rendering styles for the same object/scene.
-        //glEnable(GL_SCISSOR_TEST);
-        //int scissor[4];
-        //glGetIntegerv(GL_SCISSOR_BOX, scissor);
-        //glScissor(scissor[0], scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(false);
-        //Viewer::draw();
-        //glScissor(scissor[2] * 0.5f, scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(true);
-        //Viewer::draw();
-        //glScissor(scissor[0], scissor[1], scissor[2], scissor[3]);
+#if 0
+        // Example code: split the view to have different rendering styles for the same object/scene.
+        glEnable(GL_SCISSOR_TEST);
+        int viewport[4];
+        glGetIntegerv(GL_VIEWPORT, viewport);
+        glScissor(viewport[0], viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->triangles_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[2] * 0.5f, viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->lines_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
+
+#else 
 
         for (const auto m : models_) {
             if (!m->renderer()->is_visible())
@@ -1786,6 +1793,7 @@ namespace easy3d {
             draw_face_labels(current_model(), texter_, 1, vec3(0, 0, 1));
             draw_vertex_labels(current_model(), texter_, 1, vec3(0, 1, 0));
         }
+#endif
 #endif
     }
 
diff --git a/tutorials/Tutorial_203_Viewer_wxWidgets/viewer.cpp b/tutorials/Tutorial_203_Viewer_wxWidgets/viewer.cpp
index 01986d8c..7fbb68b8 100644
--- a/tutorials/Tutorial_203_Viewer_wxWidgets/viewer.cpp
+++ b/tutorials/Tutorial_203_Viewer_wxWidgets/viewer.cpp
@@ -789,17 +789,24 @@ namespace easy3d {
 
 
     void Viewer::draw() const {
-        // To have split views of different rendering styles for the same object/scene.
-        //glEnable(GL_SCISSOR_TEST);
-        //int scissor[4];
-        //glGetIntegerv(GL_SCISSOR_BOX, scissor);
-        //glScissor(scissor[0], scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(false);
-        //Viewer::draw();
-        //glScissor(scissor[2] * 0.5f, scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(true);
-        //Viewer::draw();
-        //glScissor(scissor[0], scissor[1], scissor[2], scissor[3]);
+#if 0
+        // Example code: split the view to have different rendering styles for the same object/scene.
+        glEnable(GL_SCISSOR_TEST);
+        int viewport[4];
+        glGetIntegerv(GL_VIEWPORT, viewport);
+        glScissor(viewport[0], viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->triangles_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[2] * 0.5f, viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->lines_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
+
+#else 
 
         for (const auto m : models_) {
             if (!m->renderer()->is_visible())
@@ -837,5 +844,6 @@ namespace easy3d {
             if (d->is_visible())
                 d->draw(camera());
         }
+#endif
     }
 }
\ No newline at end of file
diff --git a/tutorials/Tutorial_204_Viewer_Qt/viewer.cpp b/tutorials/Tutorial_204_Viewer_Qt/viewer.cpp
index c8305241..0b95daf1 100644
--- a/tutorials/Tutorial_204_Viewer_Qt/viewer.cpp
+++ b/tutorials/Tutorial_204_Viewer_Qt/viewer.cpp
@@ -984,17 +984,24 @@ namespace easy3d {
 
 
     void Viewer::draw() {
-        // To have split views of different rendering styles for the same object/scene.
-        //glEnable(GL_SCISSOR_TEST);
-        //int scissor[4];
-        //glGetIntegerv(GL_SCISSOR_BOX, scissor);
-        //glScissor(scissor[0], scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(false);
-        //Viewer::draw();
-        //glScissor(scissor[2] * 0.5f, scissor[1], scissor[2] * 0.5f, scissor[3]);
-        //current_model()->renderer()->get_lines_drawable("edges")->set_visible(true);
-        //Viewer::draw();
-        //glScissor(scissor[0], scissor[1], scissor[2], scissor[3]);
+#if 0
+        // Example code: split the view to have different rendering styles for the same object/scene.
+        glEnable(GL_SCISSOR_TEST);
+        int viewport[4];
+        glGetIntegerv(GL_VIEWPORT, viewport);
+        glScissor(viewport[0], viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->triangles_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[2] * 0.5f, viewport[1], viewport[2] * 0.5f, viewport[3]);
+        for (const auto m : models_) {
+            for (auto d : m->renderer()->lines_drawables())
+                d->draw(camera());
+        }
+        glScissor(viewport[0], viewport[1], viewport[2], viewport[3]);
+
+#else 
 
         easy3d_debug_log_gl_error
 
@@ -1030,6 +1037,7 @@ namespace easy3d {
 			if (d->is_visible())
 				d->draw(camera());
 		}
+#endif
     }
 
 }
\ No newline at end of file