diff --git a/resources/shaders/gouraud_light_instanced.vs b/resources/shaders/gouraud_light_instanced.vs
index a8931361d0..997b6a2bf9 100644
--- a/resources/shaders/gouraud_light_instanced.vs
+++ b/resources/shaders/gouraud_light_instanced.vs
@@ -34,7 +34,9 @@ void main()
     float NdotL = max(dot(eye_normal, LIGHT_TOP_DIR), 0.0);
 
     intensity.x = INTENSITY_AMBIENT + NdotL * LIGHT_TOP_DIFFUSE;
-    vec4 world_position = vec4(v_position * vec3(vec2(i_scales.x), i_scales.y) + i_offset, 1.0);
+	float width = 1.5 * i_scales.x;
+	float height = 1.5 * i_scales.y;
+    vec4 world_position = vec4(v_position * vec3(vec2(width), height) + i_offset - vec3(0.0, 0.0, 0.5 * i_scales.y), 1.0);
     vec3 eye_position = (gl_ModelViewMatrix * world_position).xyz;
     intensity.y = LIGHT_TOP_SPECULAR * pow(max(dot(-normalize(eye_position), reflect(-LIGHT_TOP_DIR, eye_normal)), 0.0), LIGHT_TOP_SHININESS);
 
diff --git a/src/slic3r/GUI/GCodeViewer.cpp b/src/slic3r/GUI/GCodeViewer.cpp
index 7e8e587a6e..ac97b8dbc5 100644
--- a/src/slic3r/GUI/GCodeViewer.cpp
+++ b/src/slic3r/GUI/GCodeViewer.cpp
@@ -1414,9 +1414,9 @@ void GCodeViewer::load_toolpaths(const GCodeProcessor::Result& gcode_result)
         instances.push_back(curr.position.y());
         instances.push_back(curr.position.z());
         // append width
-        instances.push_back(1.5f * curr.width);
+        instances.push_back(curr.width);
         // append height
-        instances.push_back(1.5f * curr.height);
+        instances.push_back(curr.height);
 
         // append id
         instances_ids.push_back(move_id);
@@ -1428,7 +1428,7 @@ void GCodeViewer::load_toolpaths(const GCodeProcessor::Result& gcode_result)
         const double width = static_cast<double>(1.5f * curr.width);
         const double height = static_cast<double>(1.5f * curr.height);
 
-        const Transform3d trafo = Geometry::assemble_transform(curr.position.cast<double>(), Vec3d::Zero(), { width, width, height });
+        const Transform3d trafo = Geometry::assemble_transform((curr.position - 0.5f * curr.height * Vec3f::UnitZ()).cast<double>(), Vec3d::Zero(), { width, width, height });
         const Eigen::Matrix<double, 3, 3, Eigen::DontAlign> normal_matrix = trafo.matrix().template block<3, 3>(0, 0).inverse().transpose();
 
         for (const auto& entity : data.entities) {