diff --git a/src/slic3r/GUI/3DScene.cpp b/src/slic3r/GUI/3DScene.cpp
index c0d9c4005..193673260 100644
--- a/src/slic3r/GUI/3DScene.cpp
+++ b/src/slic3r/GUI/3DScene.cpp
@@ -216,6 +216,7 @@ GLVolume::GLVolume(float r, float g, float b, float a)
     , m_world_matrix_dirty(true)
     , m_transformed_bounding_box_dirty(true)
 #endif // ENABLE_MODELVOLUME_TRANSFORM
+    , m_sla_shift_z(0.0)
     , m_transformed_convex_hull_bounding_box_dirty(true)
     , m_convex_hull(nullptr)
     , m_convex_hull_owned(false)
@@ -380,7 +381,14 @@ void GLVolume::set_convex_hull(const TriangleMesh *convex_hull, bool owned)
     m_convex_hull_owned = owned;
 }
 
-#if !ENABLE_MODELVOLUME_TRANSFORM
+#if ENABLE_MODELVOLUME_TRANSFORM
+Transform3d GLVolume::world_matrix() const
+{
+    Transform3d m = m_instance_transformation.get_matrix() * m_volume_transformation.get_matrix();
+    m.translation()(2) += m_sla_shift_z;
+    return m;
+}
+#else
 const Transform3f& GLVolume::world_matrix() const
 {
     if (m_world_matrix_dirty)
@@ -390,7 +398,7 @@ const Transform3f& GLVolume::world_matrix() const
     }
     return m_world_matrix;
 }
-#endif // !ENABLE_MODELVOLUME_TRANSFORM
+#endif // ENABLE_MODELVOLUME_TRANSFORM
 
 const BoundingBoxf3& GLVolume::transformed_bounding_box() const
 {
diff --git a/src/slic3r/GUI/3DScene.hpp b/src/slic3r/GUI/3DScene.hpp
index c1a3a3af2..eb6bb9311 100644
--- a/src/slic3r/GUI/3DScene.hpp
+++ b/src/slic3r/GUI/3DScene.hpp
@@ -278,6 +278,8 @@ private:
     // Whether or not is needed to recalculate the world matrix.
     mutable bool          m_world_matrix_dirty;
 #endif // ENABLE_MODELVOLUME_TRANSFORM
+    // Shift in z required by sla supports+pad
+    double m_sla_shift_z;
     // Bounding box of this volume, in unscaled coordinates.
     mutable BoundingBoxf3 m_transformed_bounding_box;
     // Whether or not is needed to recalculate the transformed bounding box.
@@ -426,6 +428,9 @@ public:
     const Vec3d& get_offset() const;
     void set_offset(const Vec3d& offset);
 #endif // ENABLE_MODELVOLUME_TRANSFORM
+     
+    double get_sla_shift_z() const { return m_sla_shift_z; }
+    void set_sla_shift_z(double z) { m_sla_shift_z = z; }
 
     void set_convex_hull(const TriangleMesh *convex_hull, bool owned);
 
@@ -434,7 +439,7 @@ public:
     int                 instance_idx() const { return this->composite_id.instance_id; }
 
 #if ENABLE_MODELVOLUME_TRANSFORM
-    Transform3d world_matrix() const { return m_instance_transformation.get_matrix() * m_volume_transformation.get_matrix(); }
+    Transform3d world_matrix() const;
 #else
     const Transform3f&   world_matrix() const;
 #endif // ENABLE_MODELVOLUME_TRANSFORM
diff --git a/src/slic3r/GUI/GLCanvas3D.cpp b/src/slic3r/GUI/GLCanvas3D.cpp
index 7a618436e..2f704a9ba 100644
--- a/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/src/slic3r/GUI/GLCanvas3D.cpp
@@ -3937,6 +3937,7 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                     delete volume;
             } else {
                 // This GLVolume will be reused.
+                volume->set_sla_shift_z(0.0);
                 map_glvolume_old_to_new[volume_id] = glvolumes_new.size();
                 mvs->volume_idx = glvolumes_new.size();
                 glvolumes_new.emplace_back(volume);
@@ -4045,7 +4046,7 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                                 instances[istep].emplace_back(std::pair<size_t, size_t>(instance_idx, print_instance_idx));
                             else
 								// Recycling an old GLVolume. Update the Object/Instance indices into the current Model.
-                                m_volumes.volumes[it->volume_idx]->composite_id = GLVolume::CompositeID(object_idx, -1, instance_idx);
+                                m_volumes.volumes[it->volume_idx]->composite_id = GLVolume::CompositeID(object_idx, m_volumes.volumes[it->volume_idx]->volume_idx(), instance_idx);
                         }
                 }
 
@@ -4060,11 +4061,11 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                 {
                     // If any volume has been added
                     // Shift-up all volumes of the object so that it has the right elevation with respect to the print bed
-                    Vec3d shift_z(0.0, 0.0, print_object->get_elevation());
+                    double shift_z = print_object->get_elevation();
                     for (GLVolume* volume : m_volumes.volumes)
                     {
                         if (volume->object_idx() == object_idx)
-                            volume->set_instance_offset(volume->get_instance_offset() + shift_z);
+                            volume->set_sla_shift_z(shift_z);
                     }
                 }
             }