diff --git a/xs/CMakeLists.txt b/xs/CMakeLists.txt
index b7d99ed69..1f2a93375 100644
--- a/xs/CMakeLists.txt
+++ b/xs/CMakeLists.txt
@@ -177,6 +177,7 @@ add_library(libslic3r STATIC
     ${LIBDIR}/libslic3r/SurfaceCollection.hpp
     ${LIBDIR}/libslic3r/SVG.cpp
     ${LIBDIR}/libslic3r/SVG.hpp
+    ${LIBDIR}/libslic3r/Technologies.hpp
     ${LIBDIR}/libslic3r/TriangleMesh.cpp
     ${LIBDIR}/libslic3r/TriangleMesh.hpp
     ${LIBDIR}/libslic3r/SLABasePool.hpp
diff --git a/xs/src/libslic3r/Format/3mf.cpp b/xs/src/libslic3r/Format/3mf.cpp
index 464cbb8e6..c5c37a128 100644
--- a/xs/src/libslic3r/Format/3mf.cpp
+++ b/xs/src/libslic3r/Format/3mf.cpp
@@ -1252,9 +1252,13 @@ namespace Slic3r {
         // we extract from the given matrix only the values currently used
 
         // translation
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        Vec3d offset(transform(0, 3), transform(1, 3), transform(2, 3));
+#else
         double offset_x = transform(0, 3);
         double offset_y = transform(1, 3);
         double offset_z = transform(2, 3);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 
         // scale
         double sx = ::sqrt(sqr(transform(0, 0)) + sqr(transform(1, 0)) + sqr(transform(2, 0)));
@@ -1287,8 +1291,12 @@ namespace Slic3r {
 
         double angle_z = (rotation.axis() == Vec3d::UnitZ()) ? rotation.angle() : -rotation.angle();
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        instance.set_offset(offset);
+#else
         instance.offset(0) = offset_x;
         instance.offset(1) = offset_y;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         instance.scaling_factor = sx;
         instance.rotation = angle_z;
     }
diff --git a/xs/src/libslic3r/Format/AMF.cpp b/xs/src/libslic3r/Format/AMF.cpp
index 81617ad72..3f3839d43 100644
--- a/xs/src/libslic3r/Format/AMF.cpp
+++ b/xs/src/libslic3r/Format/AMF.cpp
@@ -29,7 +29,12 @@
 // VERSION NUMBERS
 // 0 : .amf, .amf.xml and .zip.amf files saved by older slic3r. No version definition in them.
 // 1 : Introduction of amf versioning. No other change in data saved into amf files.
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+// 2 : Added z component of offset.
+const unsigned int VERSION_AMF = 2;
+#else
 const unsigned int VERSION_AMF = 1;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 const char* SLIC3RPE_AMF_VERSION = "slic3rpe_amf_version";
 
 const char* SLIC3R_CONFIG_TYPE = "slic3rpe_config";
@@ -119,19 +124,31 @@ struct AMFParserContext
         NODE_TYPE_INSTANCE,             // amf/constellation/instance
         NODE_TYPE_DELTAX,               // amf/constellation/instance/deltax
         NODE_TYPE_DELTAY,               // amf/constellation/instance/deltay
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        NODE_TYPE_DELTAZ,               // amf/constellation/instance/deltaz
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         NODE_TYPE_RZ,                   // amf/constellation/instance/rz
         NODE_TYPE_SCALE,                // amf/constellation/instance/scale
         NODE_TYPE_METADATA,             // anywhere under amf/*/metadata
     };
 
     struct Instance {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        Instance() : deltax_set(false), deltay_set(false), deltaz_set(false), rz_set(false), scale_set(false) {}
+#else
         Instance() : deltax_set(false), deltay_set(false), rz_set(false), scale_set(false) {}
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         // Shift in the X axis.
         float deltax;
         bool  deltax_set;
         // Shift in the Y axis.
         float deltay;
         bool  deltay_set;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        // Shift in the Z axis.
+        float deltaz;
+        bool  deltaz_set;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         // Rotation around the Z axis.
         float rz;
         bool  rz_set;
@@ -254,6 +271,10 @@ void AMFParserContext::startElement(const char *name, const char **atts)
                 node_type_new = NODE_TYPE_DELTAX; 
             else if (strcmp(name, "deltay") == 0)
                 node_type_new = NODE_TYPE_DELTAY;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            else if (strcmp(name, "deltaz") == 0)
+                node_type_new = NODE_TYPE_DELTAZ;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             else if (strcmp(name, "rz") == 0)
                 node_type_new = NODE_TYPE_RZ;
             else if (strcmp(name, "scale") == 0)
@@ -314,7 +335,15 @@ void AMFParserContext::characters(const XML_Char *s, int len)
     {
         switch (m_path.size()) {
         case 4:
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            if (m_path.back() == NODE_TYPE_DELTAX || 
+                m_path.back() == NODE_TYPE_DELTAY || 
+                m_path.back() == NODE_TYPE_DELTAZ || 
+                m_path.back() == NODE_TYPE_RZ || 
+                m_path.back() == NODE_TYPE_SCALE)
+#else
             if (m_path.back() == NODE_TYPE_DELTAX || m_path.back() == NODE_TYPE_DELTAY || m_path.back() == NODE_TYPE_RZ || m_path.back() == NODE_TYPE_SCALE)
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                 m_value[0].append(s, len);
             break;
         case 6:
@@ -354,6 +383,14 @@ void AMFParserContext::endElement(const char * /* name */)
         m_instance->deltay_set = true;
         m_value[0].clear();
         break;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    case NODE_TYPE_DELTAZ:
+        assert(m_instance);
+        m_instance->deltaz = float(atof(m_value[0].c_str()));
+        m_instance->deltaz_set = true;
+        m_value[0].clear();
+        break;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     case NODE_TYPE_RZ:
         assert(m_instance);
         m_instance->rz = float(atof(m_value[0].c_str()));
@@ -498,8 +535,12 @@ void AMFParserContext::endDocument()
         for (const Instance &instance : object.second.instances)
             if (instance.deltax_set && instance.deltay_set) {
                 ModelInstance *mi = m_model.objects[object.second.idx]->add_instance();
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                mi->set_offset(Vec3d((double)instance.deltax, (double)instance.deltay, (double)instance.deltaz));
+#else
                 mi->offset(0) = instance.deltax;
                 mi->offset(1) = instance.deltay;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                 mi->rotation = instance.rz_set ? instance.rz : 0.f;
                 mi->scaling_factor = instance.scale_set ? instance.scale : 1.f;
             }
@@ -800,12 +841,21 @@ bool store_amf(const char *path, Model *model, Print* print, bool export_print_c
                     "    <instance objectid=\"" PRINTF_ZU "\">\n"
                     "      <deltax>%lf</deltax>\n"
                     "      <deltay>%lf</deltay>\n"
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                    "      <deltaz>%lf</deltaz>\n"
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                     "      <rz>%lf</rz>\n"
                     "      <scale>%lf</scale>\n"
                     "    </instance>\n",
                     object_id,
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                    instance->get_offset(X),
+                    instance->get_offset(Y),
+                    instance->get_offset(Z),
+#else
                     instance->offset(0),
                     instance->offset(1),
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                     instance->rotation,
                     instance->scaling_factor);
                 //FIXME missing instance->scaling_factor
diff --git a/xs/src/libslic3r/Format/PRUS.cpp b/xs/src/libslic3r/Format/PRUS.cpp
index 3cf3fc075..45eb56c63 100644
--- a/xs/src/libslic3r/Format/PRUS.cpp
+++ b/xs/src/libslic3r/Format/PRUS.cpp
@@ -166,7 +166,11 @@ bool load_prus(const char *path, Model *model)
             float  trafo[3][4] = { 0 };
             double instance_rotation = 0.;
             double instance_scaling_factor = 1.f;
-            Vec2d instance_offset(0., 0.); 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            Vec3d instance_offset = Vec3d::Zero();
+#else
+            Vec2d instance_offset(0., 0.);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             bool   trafo_set = false;
             unsigned int group_id     = (unsigned int)-1;
             unsigned int extruder_id  = (unsigned int)-1;
@@ -207,8 +211,12 @@ bool load_prus(const char *path, Model *model)
                         for (size_t c = 0; c < 3; ++ c)
                             trafo[r][c] += mat_trafo(r, c);
                     }
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                    instance_offset = Vec3d((double)(position[0] - zero[0]), (double)(position[1] - zero[1]), (double)(position[2] - zero[2]));
+#else
                     instance_offset(0) = position[0] - zero[0];
                     instance_offset(1) = position[1] - zero[1];
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                     trafo[2][3] = position[2] / instance_scaling_factor;
                     trafo_set = true;
                 }
@@ -360,8 +368,12 @@ bool load_prus(const char *path, Model *model)
                         ModelInstance *instance     = model_object->add_instance();
                         instance->rotation          = instance_rotation;
                         instance->scaling_factor    = instance_scaling_factor;
-                        instance->offset            = instance_offset;
-                        ++ num_models;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                        instance->set_offset(instance_offset);
+#else
+                        instance->offset = instance_offset;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
+                        ++num_models;
                         if (group_id != (size_t)-1)
                             group_to_model_object[group_id] = model_object;
                     } else {
diff --git a/xs/src/libslic3r/Model.cpp b/xs/src/libslic3r/Model.cpp
index 19c474cad..1088c2e87 100644
--- a/xs/src/libslic3r/Model.cpp
+++ b/xs/src/libslic3r/Model.cpp
@@ -242,10 +242,19 @@ void Model::center_instances_around_point(const Vec2d &point)
         for (size_t i = 0; i < o->instances.size(); ++ i)
             bb.merge(o->instance_bounding_box(i, false));
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    Vec2d shift2 = point - to_2d(bb.center());
+    Vec3d shift3 = Vec3d(shift2(0), shift2(1), 0.0);
+#else
     Vec2d shift = point - 0.5 * to_2d(bb.size()) - to_2d(bb.min);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     for (ModelObject *o : this->objects) {
         for (ModelInstance *i : o->instances)
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            i->set_offset(i->get_offset() + shift3);
+#else
             i->offset += shift;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         o->invalidate_bounding_box();
     }
 }
@@ -311,8 +320,13 @@ bool Model::arrange_objects(coordf_t dist, const BoundingBoxf* bb)
     size_t idx = 0;
     for (ModelObject *o : this->objects) {
         for (ModelInstance *i : o->instances) {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            Vec2d offset_xy = positions[idx] - instance_centers[idx];
+            i->set_offset(Vec3d(offset_xy(0), offset_xy(1), i->get_offset(Z)));
+#else
             i->offset = positions[idx] - instance_centers[idx];
-            ++ idx;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
+            ++idx;
         }
         o->invalidate_bounding_box();
     }
@@ -336,7 +350,11 @@ void Model::duplicate(size_t copies_num, coordf_t dist, const BoundingBoxf* bb)
         for (const ModelInstance *i : instances) {
             for (const Vec2d &pos : positions) {
                 ModelInstance *instance = o->add_instance(*i);
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                instance->set_offset(instance->get_offset() + Vec3d(pos(0), pos(1), 0.0));
+#else
                 instance->offset += pos;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             }
         }
         o->invalidate_bounding_box();
@@ -366,13 +384,21 @@ void Model::duplicate_objects_grid(size_t x, size_t y, coordf_t dist)
     ModelObject* object = this->objects.front();
     object->clear_instances();
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    Vec3d ext_size = object->bounding_box().size() + dist * Vec3d::Ones();
+#else
     Vec3d size = object->bounding_box().size();
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 
     for (size_t x_copy = 1; x_copy <= x; ++x_copy) {
         for (size_t y_copy = 1; y_copy <= y; ++y_copy) {
             ModelInstance* instance = object->add_instance();
-            instance->offset(0) = (size(0) + dist) * (x_copy-1);
-            instance->offset(1) = (size(1) + dist) * (y_copy-1);
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            instance->set_offset(Vec3d(ext_size(0) * (double)(x_copy - 1), ext_size(1) * (double)(y_copy - 1), 0.0));
+#else
+            instance->offset(0) = (size(0) + dist) * (x_copy - 1);
+            instance->offset(1) = (size(1) + dist) * (y_copy - 1);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         }
     }
 }
@@ -676,12 +702,21 @@ void ModelObject::center_around_origin()
     this->translate(shift);
     this->origin_translation += shift;
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    // set z to zero, translation in z has already been done within the mesh
+    shift(2) = 0.0;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
+
     if (!this->instances.empty()) {
         for (ModelInstance *i : this->instances) {
             // apply rotation and scaling to vector as well before translating instance,
             // in order to leave final position unaltered
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            i->set_offset(i->get_offset() + i->transform_vector(-shift, true));
+#else
             Vec3d i_shift = i->world_matrix(true) * shift;
             i->offset -= to_2d(i_shift);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         }
         this->invalidate_bounding_box();
     }
@@ -1004,8 +1039,13 @@ BoundingBoxf3 ModelInstance::transform_mesh_bounding_box(const TriangleMesh* mes
         }
         // Translate the bounding box.
         if (! dont_translate) {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            bbox.min += this->m_offset;
+            bbox.max += this->m_offset;
+#else
             Eigen::Map<Vec2d>(bbox.min.data()) += this->offset;
             Eigen::Map<Vec2d>(bbox.max.data()) += this->offset;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
         }
     }
     return bbox;
@@ -1032,7 +1072,11 @@ Transform3d ModelInstance::world_matrix(bool dont_translate, bool dont_rotate, b
     Transform3d m = Transform3d::Identity();
 
     if (!dont_translate)
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        m.translate(m_offset);
+#else
         m.translate(Vec3d(offset(0), offset(1), 0.0));
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 
     if (!dont_rotate)
         m.rotate(Eigen::AngleAxisd(rotation, Vec3d::UnitZ()));
diff --git a/xs/src/libslic3r/Model.hpp b/xs/src/libslic3r/Model.hpp
index 8a8af481c..e8cd5473b 100644
--- a/xs/src/libslic3r/Model.hpp
+++ b/xs/src/libslic3r/Model.hpp
@@ -224,15 +224,32 @@ public:
 
     friend class ModelObject;
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+private:
+    Vec3d m_offset;              // in unscaled coordinates
+
+public:
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
+
     double rotation;            // Rotation around the Z axis, in radians around mesh center point
     double scaling_factor;
+#if !ENABLE_MODELINSTANCE_3D_OFFSET
     Vec2d offset;              // in unscaled coordinates
-    
+#endif // !ENABLE_MODELINSTANCE_3D_OFFSET
+
     // flag showing the position of this instance with respect to the print volume (set by Print::validate() using ModelObject::check_instances_print_volume_state())
     EPrintVolumeState print_volume_state;
 
     ModelObject* get_object() const { return this->object; }
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    const Vec3d& get_offset() const { return m_offset; }
+    double get_offset(Axis axis) const { return m_offset(axis); }
+
+    void set_offset(const Vec3d& offset) { m_offset = offset; }
+    void set_offset(Axis axis, double offset) { m_offset(axis) = offset; }
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
+
     // To be called on an external mesh
     void transform_mesh(TriangleMesh* mesh, bool dont_translate = false) const;
     // Calculate a bounding box of a transformed mesh. To be called on an external mesh.
@@ -252,9 +269,15 @@ private:
     // Parent object, owning this instance.
     ModelObject* object;
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    ModelInstance(ModelObject *object) : rotation(0), scaling_factor(1), m_offset(Vec3d::Zero()), object(object), print_volume_state(PVS_Inside) {}
+    ModelInstance(ModelObject *object, const ModelInstance &other) :
+        rotation(other.rotation), scaling_factor(other.scaling_factor), m_offset(other.m_offset), object(object), print_volume_state(PVS_Inside) {}
+#else
     ModelInstance(ModelObject *object) : rotation(0), scaling_factor(1), offset(Vec2d::Zero()), object(object), print_volume_state(PVS_Inside) {}
     ModelInstance(ModelObject *object, const ModelInstance &other) :
         rotation(other.rotation), scaling_factor(other.scaling_factor), offset(other.offset), object(object), print_volume_state(PVS_Inside) {}
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 };
 
 
diff --git a/xs/src/libslic3r/ModelArrange.hpp b/xs/src/libslic3r/ModelArrange.hpp
index a8e7936d6..3c2c2aa29 100644
--- a/xs/src/libslic3r/ModelArrange.hpp
+++ b/xs/src/libslic3r/ModelArrange.hpp
@@ -517,8 +517,13 @@ ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
                     if(item.vertexCount() > 3) {
                         item.rotation(objinst->rotation);
                         item.translation( {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                            ClipperLib::cInt(objinst->get_offset(X) / SCALING_FACTOR),
+                            ClipperLib::cInt(objinst->get_offset(Y) / SCALING_FACTOR)
+#else
                             ClipperLib::cInt(objinst->offset(0)/SCALING_FACTOR),
                             ClipperLib::cInt(objinst->offset(1)/SCALING_FACTOR)
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                         });
                         ret.emplace_back(objinst, item);
                     }
@@ -655,11 +660,19 @@ void applyResult(
         // appropriately
         auto off = item.translation();
         Radians rot = item.rotation();
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        Vec3d foff(off.X*SCALING_FACTOR + batch_offset, off.Y*SCALING_FACTOR, 0.0);
+#else
         Vec2d foff(off.X*SCALING_FACTOR + batch_offset, off.Y*SCALING_FACTOR);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 
         // write the tranformation data into the model instance
         inst_ptr->rotation = rot;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        inst_ptr->set_offset(foff);
+#else
         inst_ptr->offset = foff;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     }
 }
 
diff --git a/xs/src/libslic3r/PrintObject.cpp b/xs/src/libslic3r/PrintObject.cpp
index d03b99416..9d1d58d6d 100644
--- a/xs/src/libslic3r/PrintObject.cpp
+++ b/xs/src/libslic3r/PrintObject.cpp
@@ -102,8 +102,16 @@ bool PrintObject::reload_model_instances()
     copies.reserve(this->_model_object->instances.size());
     for (const ModelInstance *mi : this->_model_object->instances)
     {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        if (mi->is_printable())
+        {
+            const Vec3d& offset = mi->get_offset();
+            copies.emplace_back(Point::new_scale(offset(0), offset(1)));
+        }
+#else
         if (mi->is_printable())
             copies.emplace_back(Point::new_scale(mi->offset(0), mi->offset(1)));
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     }
     return this->set_copies(copies);
 }
diff --git a/xs/src/libslic3r/Technologies.hpp b/xs/src/libslic3r/Technologies.hpp
new file mode 100644
index 000000000..5c4f8617d
--- /dev/null
+++ b/xs/src/libslic3r/Technologies.hpp
@@ -0,0 +1,12 @@
+#ifndef _technologies_h_
+#define _technologies_h_
+
+// 1.42.0 techs
+#define ENABLE_1_42_0 1
+
+// Add z coordinate to model instances' offset
+#define ENABLE_MODELINSTANCE_3D_OFFSET (1 && ENABLE_1_42_0)
+
+#endif // _technologies_h_
+
+
diff --git a/xs/src/libslic3r/libslic3r.h b/xs/src/libslic3r/libslic3r.h
index 925e93031..cf0a19f7a 100644
--- a/xs/src/libslic3r/libslic3r.h
+++ b/xs/src/libslic3r/libslic3r.h
@@ -13,6 +13,8 @@
 #include <vector>
 #include <boost/thread.hpp>
 
+#include "Technologies.hpp"
+
 #define SLIC3R_FORK_NAME "Slic3r Prusa Edition"
 #define SLIC3R_VERSION "1.41.0"
 #define SLIC3R_BUILD "UNKNOWN"
diff --git a/xs/src/slic3r/GUI/3DScene.cpp b/xs/src/slic3r/GUI/3DScene.cpp
index 968b5fbcb..f755fdb03 100644
--- a/xs/src/slic3r/GUI/3DScene.cpp
+++ b/xs/src/slic3r/GUI/3DScene.cpp
@@ -684,7 +684,11 @@ std::vector<int> GLVolumeCollection::load_object(
             }
             v.is_modifier = model_volume->modifier;
             v.shader_outside_printer_detection_enabled = !model_volume->modifier;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            v.set_offset(instance->get_offset());
+#else
             v.set_offset(Vec3d(instance->offset(0), instance->offset(1), 0.0));
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             v.set_rotation(instance->rotation);
             v.set_scaling_factor(instance->scaling_factor);
         }
diff --git a/xs/src/slic3r/GUI/GLCanvas3D.cpp b/xs/src/slic3r/GUI/GLCanvas3D.cpp
index be0e71aa3..78919623f 100644
--- a/xs/src/slic3r/GUI/GLCanvas3D.cpp
+++ b/xs/src/slic3r/GUI/GLCanvas3D.cpp
@@ -1140,8 +1140,10 @@ bool GLCanvas3D::Gizmos::init(GLCanvas3D& parent)
     if (!gizmo->init())
         return false;
 
+#if !ENABLE_MODELINSTANCE_3D_OFFSET
     // temporary disable z grabber
     gizmo->disable_grabber(2);
+#endif // !ENABLE_MODELINSTANCE_3D_OFFSET
 
     m_gizmos.insert(GizmosMap::value_type(Move, gizmo));
 
@@ -2375,7 +2377,11 @@ void GLCanvas3D::update_gizmos_data()
             ModelInstance* model_instance = model_object->instances[0];
             if (model_instance != nullptr)
             {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                m_gizmos.set_position(model_instance->get_offset());
+#else
                 m_gizmos.set_position(Vec3d(model_instance->offset(0), model_instance->offset(1), 0.0));
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                 m_gizmos.set_scale(model_instance->scaling_factor);
                 m_gizmos.set_angle_z(model_instance->rotation);
                 m_gizmos.set_flattening_data(model_object);
@@ -5360,8 +5366,12 @@ void GLCanvas3D::_on_move(const std::vector<int>& volume_idxs)
             ModelObject* model_object = m_model->objects[obj_idx];
             if (model_object != nullptr)
             {
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+                model_object->instances[instance_idx]->set_offset(volume->get_offset());
+#else
                 const Vec3d& offset = volume->get_offset();
                 model_object->instances[instance_idx]->offset = Vec2d(offset(0), offset(1));
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
                 model_object->invalidate_bounding_box();
                 update_position_values();
                 object_moved = true;
diff --git a/xs/src/slic3r/GUI/GLGizmo.cpp b/xs/src/slic3r/GUI/GLGizmo.cpp
index 9c209035b..e23958c1d 100644
--- a/xs/src/slic3r/GUI/GLGizmo.cpp
+++ b/xs/src/slic3r/GUI/GLGizmo.cpp
@@ -1032,6 +1032,7 @@ GLGizmoMove3D::GLGizmoMove3D(GLCanvas3D& parent)
     , m_position(Vec3d::Zero())
     , m_starting_drag_position(Vec3d::Zero())
     , m_starting_box_center(Vec3d::Zero())
+    , m_starting_box_bottom_center(Vec3d::Zero())
 {
 }
 
@@ -1065,17 +1066,19 @@ void GLGizmoMove3D::on_start_dragging(const BoundingBoxf3& box)
     {
         m_starting_drag_position = m_grabbers[m_hover_id].center;
         m_starting_box_center = box.center();
+        m_starting_box_bottom_center = box.center();
+        m_starting_box_bottom_center(2) = box.min(2);
     }
 }
 
 void GLGizmoMove3D::on_update(const Linef3& mouse_ray)
 {
     if (m_hover_id == 0)
-        m_position(0) = 2.0 * m_starting_box_center(0) + calc_displacement(1, mouse_ray) - m_starting_drag_position(0);
+        m_position(0) = 2.0 * m_starting_box_center(0) + calc_projection(X, 1, mouse_ray) - m_starting_drag_position(0);
     else if (m_hover_id == 1)
-        m_position(1) = 2.0 * m_starting_box_center(1) + calc_displacement(2, mouse_ray) - m_starting_drag_position(1);
+        m_position(1) = 2.0 * m_starting_box_center(1) + calc_projection(Y, 2, mouse_ray) - m_starting_drag_position(1);
     else if (m_hover_id == 2)
-        m_position(2) = 2.0 * m_starting_box_center(2) + calc_displacement(1, mouse_ray) - m_starting_drag_position(2);
+        m_position(2) = 2.0 * m_starting_box_bottom_center(2) + calc_projection(Z, 1, mouse_ray) - m_starting_drag_position(2);
 }
 
 void GLGizmoMove3D::on_render(const BoundingBoxf3& box) const
@@ -1144,40 +1147,40 @@ void GLGizmoMove3D::on_render_for_picking(const BoundingBoxf3& box) const
     render_grabbers_for_picking(box);
 }
 
-double GLGizmoMove3D::calc_displacement(unsigned int preferred_plane_id, const Linef3& mouse_ray) const
+double GLGizmoMove3D::calc_projection(Axis axis, unsigned int preferred_plane_id, const Linef3& mouse_ray) const
 {
-    double displacement = 0.0;
+    double projection = 0.0;
 
-    Vec3d starting_vec = m_starting_drag_position - m_starting_box_center;
+    Vec3d starting_vec = (axis == Z) ? m_starting_drag_position - m_starting_box_bottom_center : m_starting_drag_position - m_starting_box_center;
     double len_starting_vec = starting_vec.norm();
     if (len_starting_vec == 0.0)
-        return displacement;
+        return projection;
 
     Vec3d starting_vec_dir = starting_vec.normalized();
     Vec3d mouse_dir = mouse_ray.unit_vector();
 
     unsigned int plane_id = select_best_plane(mouse_dir, preferred_plane_id);
 
-    switch (plane_id)
+    switch (plane_id) 
     {
     case 0:
     {
-        displacement = starting_vec_dir.dot(intersection_on_plane_xy(mouse_ray, m_starting_box_center));
+        projection = starting_vec_dir.dot(intersection_on_plane_xy(mouse_ray, (axis == Z) ? m_starting_box_bottom_center : m_starting_box_center));
         break;
     }
     case 1:
     {
-        displacement = starting_vec_dir.dot(intersection_on_plane_xz(mouse_ray, m_starting_box_center));
+        projection = starting_vec_dir.dot(intersection_on_plane_xz(mouse_ray, (axis == Z) ? m_starting_box_bottom_center : m_starting_box_center));
         break;
     }
     case 2:
     {
-        displacement = starting_vec_dir.dot(intersection_on_plane_yz(mouse_ray, m_starting_box_center));
+        projection = starting_vec_dir.dot(intersection_on_plane_yz(mouse_ray, (axis == Z) ? m_starting_box_bottom_center : m_starting_box_center));
         break;
     }
     }
 
-    return displacement;
+    return projection;
 }
 
 GLGizmoFlatten::GLGizmoFlatten(GLCanvas3D& parent)
@@ -1233,10 +1236,19 @@ void GLGizmoFlatten::on_render(const BoundingBoxf3& box) const
         else
             ::glColor4f(0.9f, 0.9f, 0.9f, 0.5f);
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        for (Vec3d offset : m_instances_positions) {
+            offset += dragged_offset;
+#else
         for (Vec2d offset : m_instances_positions) {
             offset += to_2d(dragged_offset);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             ::glPushMatrix();
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            ::glTranslated(offset(0), offset(1), offset(2));
+#else
             ::glTranslatef((GLfloat)offset(0), (GLfloat)offset(1), 0.0f);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             ::glBegin(GL_POLYGON);
             for (const Vec3d& vertex : m_planes[i].vertices)
                 ::glVertex3f((GLfloat)vertex(0), (GLfloat)vertex(1), (GLfloat)vertex(2));
@@ -1255,9 +1267,17 @@ void GLGizmoFlatten::on_render_for_picking(const BoundingBoxf3& box) const
     for (unsigned int i = 0; i < m_planes.size(); ++i)
     {
         ::glColor3f(1.0f, 1.0f, picking_color_component(i));
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+        for (const Vec3d& offset : m_instances_positions) {
+#else
         for (const Vec2d& offset : m_instances_positions) {
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             ::glPushMatrix();
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            ::glTranslated(offset(0), offset(1), offset(2));
+#else
             ::glTranslatef((GLfloat)offset(0), (GLfloat)offset(1), 0.0f);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
             ::glBegin(GL_POLYGON);
             for (const Vec3d& vertex : m_planes[i].vertices)
                 ::glVertex3f((GLfloat)vertex(0), (GLfloat)vertex(1), (GLfloat)vertex(2));
@@ -1275,7 +1295,11 @@ void GLGizmoFlatten::set_flattening_data(const ModelObject* model_object)
     if (m_model_object && !m_model_object->instances.empty()) {
         m_instances_positions.clear();
         for (const auto* instance : m_model_object->instances)
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+            m_instances_positions.emplace_back(instance->get_offset());
+#else
             m_instances_positions.emplace_back(instance->offset);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     }
 
     if (is_plane_update_necessary())
diff --git a/xs/src/slic3r/GUI/GLGizmo.hpp b/xs/src/slic3r/GUI/GLGizmo.hpp
index fc2912d3a..2430b5af5 100644
--- a/xs/src/slic3r/GUI/GLGizmo.hpp
+++ b/xs/src/slic3r/GUI/GLGizmo.hpp
@@ -287,6 +287,7 @@ class GLGizmoMove3D : public GLGizmoBase
     Vec3d m_position;
     Vec3d m_starting_drag_position;
     Vec3d m_starting_box_center;
+    Vec3d m_starting_box_bottom_center;
 
 public:
     explicit GLGizmoMove3D(GLCanvas3D& parent);
@@ -302,7 +303,7 @@ protected:
     virtual void on_render_for_picking(const BoundingBoxf3& box) const;
 
 private:
-    double calc_displacement(unsigned int preferred_plane_id, const Linef3& mouse_ray) const;
+    double calc_projection(Axis axis, unsigned int preferred_plane_id, const Linef3& mouse_ray) const;
 };
 
 class GLGizmoFlatten : public GLGizmoBase
@@ -328,7 +329,11 @@ private:
     SourceDataSummary m_source_data;
 
     std::vector<PlaneData> m_planes;
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    Pointf3s m_instances_positions;
+#else
     std::vector<Vec2d> m_instances_positions;
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     Vec3d m_starting_center;
     const ModelObject* m_model_object = nullptr;
 
diff --git a/xs/src/slic3r/GUI/GUI_ObjectParts.cpp b/xs/src/slic3r/GUI/GUI_ObjectParts.cpp
index ff69eaffe..b2f5deeed 100644
--- a/xs/src/slic3r/GUI/GUI_ObjectParts.cpp
+++ b/xs/src/slic3r/GUI/GUI_ObjectParts.cpp
@@ -1771,9 +1771,15 @@ void update_position_values()
     auto og = get_optgroup(ogFrequentlyObjectSettings);
     auto instance = (*m_objects)[m_selected_object_id]->instances.front();
 
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    og->set_value("position_x", int(instance->get_offset(X)));
+    og->set_value("position_y", int(instance->get_offset(Y)));
+    og->set_value("position_z", int(instance->get_offset(Z)));
+#else
     og->set_value("position_x", int(instance->offset(0)));
     og->set_value("position_y", int(instance->offset(1)));
     og->set_value("position_z", 0);
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 }
 
 void update_position_values(const Vec3d& position)
diff --git a/xs/xsp/Model.xsp b/xs/xsp/Model.xsp
index a5925775d..6ae7d6415 100644
--- a/xs/xsp/Model.xsp
+++ b/xs/xsp/Model.xsp
@@ -358,15 +358,28 @@ ModelMaterial::attributes()
         %code%{ RETVAL = THIS->rotation; %};
     double scaling_factor()
         %code%{ RETVAL = THIS->scaling_factor; %};
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    Vec2d* offset()
+        %code%{ RETVAL = new Vec2d(THIS->get_offset(X), THIS->get_offset(Y)); %};
+#else
     Ref<Vec2d> offset()
         %code%{ RETVAL = &THIS->offset; %};
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
 
     void set_rotation(double val)
         %code%{ THIS->rotation = val; THIS->get_object()->invalidate_bounding_box(); %};
     void set_scaling_factor(double val)
         %code%{ THIS->scaling_factor = val; THIS->get_object()->invalidate_bounding_box(); %};
+#if ENABLE_MODELINSTANCE_3D_OFFSET
+    void set_offset(Vec2d *offset)
+        %code%{ 
+            THIS->set_offset(X, (*offset)(0));
+            THIS->set_offset(Y, (*offset)(1));
+        %};
+#else
     void set_offset(Vec2d *offset)
         %code%{ THIS->offset = *offset; %};
+#endif // ENABLE_MODELINSTANCE_3D_OFFSET
     
     void transform_mesh(TriangleMesh* mesh, bool dont_translate = false) const;
     void transform_polygon(Polygon* polygon) const;