Merge branch 'master' of https://github.com/Prusa3d/Slic3r

src/libslic3r/ModelArrange.cpp

@@ -539,7 +539,7 @@ public:
 // 2D shape from top view.
 using ShapeData2D = std::vector<std::pair<Slic3r::ModelInstance*, Item>>;
 
-ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
+ShapeData2D projectModelFromTop(const Slic3r::Model &model, const WipeTowerInfo& wti) {
     ShapeData2D ret;
 
     // Count all the items on the bin (all the object's instances)
@@ -600,6 +600,28 @@ ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
         }
     }
 
+    // The wipe tower is a separate case (in case there is one), let's duplicate the code
+    if (wti.is_wipe_tower) {
+        Points pts;
+        pts.emplace_back(coord_t(scale_(0.)), coord_t(scale_(0.)));
+        pts.emplace_back(coord_t(scale_(wti.bb_size(0))), coord_t(scale_(0.)));
+        pts.emplace_back(coord_t(scale_(wti.bb_size(0))), coord_t(scale_(wti.bb_size(1))));
+        pts.emplace_back(coord_t(scale_(-0.)), coord_t(scale_(wti.bb_size(1))));
+        pts.emplace_back(coord_t(scale_(-0.)), coord_t(scale_(0.)));
+        Polygon p(std::move(pts));
+        ClipperLib::Path clpath = Slic3rMultiPoint_to_ClipperPath(p);
+        ClipperLib::Polygon pn;
+        pn.Contour = clpath;
+        // Efficient conversion to item.
+        Item item(std::move(pn));
+        item.rotation(wti.rotation),
+        item.translation({
+        ClipperLib::cInt(wti.pos(0)/SCALING_FACTOR),
+        ClipperLib::cInt(wti.pos(1)/SCALING_FACTOR)
+        });
+        ret.emplace_back(nullptr, item);
+    }
+
     return ret;
 }
 
@@ -608,7 +630,8 @@ ShapeData2D projectModelFromTop(const Slic3r::Model &model) {
 void applyResult(
         IndexedPackGroup::value_type& group,
         Coord batch_offset,
-        ShapeData2D& shapemap)
+        ShapeData2D& shapemap,
+        WipeTowerInfo& wti)
 {
     for(auto& r : group) {
         auto idx = r.first;     // get the original item index
@@ -617,18 +640,25 @@ void applyResult(
         // Get the model instance from the shapemap using the index
         ModelInstance *inst_ptr = shapemap[idx].first;
 
-        // Get the transformation data from the item object and scale it
-        // appropriately
-        auto off = item.translation();
-        Radians rot = item.rotation();
+            // Get the transformation data from the item object and scale it
+            // appropriately
+            auto off = item.translation();
+            Radians rot = item.rotation();
 
-        Vec3d foff(off.X*SCALING_FACTOR + batch_offset,
-                   off.Y*SCALING_FACTOR,
-                   inst_ptr->get_offset()(Z));
+            Vec3d foff(off.X*SCALING_FACTOR + batch_offset,
+                       off.Y*SCALING_FACTOR,
+                       inst_ptr ? inst_ptr->get_offset()(Z) : 0.);
 
-        // write the transformation data into the model instance
-        inst_ptr->set_rotation(Z, rot);
-        inst_ptr->set_offset(foff);
+        if (inst_ptr) {
+            // write the transformation data into the model instance
+            inst_ptr->set_rotation(Z, rot);
+            inst_ptr->set_offset(foff);
+        }
+        else { // this is the wipe tower - we will modify the struct with the info
+               // and leave it up to the called to actually move the wipe tower
+            wti.pos = Vec2d(foff(0), foff(1));
+            wti.rotation = rot;
+        }
     }
 }
 
@@ -714,6 +744,7 @@ BedShapeHint bedShape(const Polyline &bed) {
 // The final client function to arrange the Model. A progress indicator and
 // a stop predicate can be also be passed to control the process.
 bool arrange(Model &model,              // The model with the geometries
+             WipeTowerInfo& wti,        // Wipe tower info
              coord_t min_obj_distance,  // Has to be in scaled (clipper) measure
              const Polyline &bed,       // The bed geometry.
              BedShapeHint bedhint,      // Hint about the bed geometry type.
@@ -726,7 +757,7 @@ bool arrange(Model &model,              // The model with the geometries
     bool ret = true;
 
     // Get the 2D projected shapes with their 3D model instance pointers
-    auto shapemap = arr::projectModelFromTop(model);
+    auto shapemap = arr::projectModelFromTop(model, wti);
 
     // Copy the references for the shapes only as the arranger expects a
     // sequence of objects convertible to Item or ClipperPolygon
@@ -796,7 +827,7 @@ bool arrange(Model &model,              // The model with the geometries
     if(result.empty() || stopcondition()) return false;
 
     if(first_bin_only) {
-        applyResult(result.front(), 0, shapemap);
+        applyResult(result.front(), 0, shapemap, wti);
     } else {
 
         const auto STRIDE_PADDING = 1.2;
@@ -806,7 +837,7 @@ bool arrange(Model &model,              // The model with the geometries
         Coord batch_offset = 0;
 
         for(auto& group : result) {
-            applyResult(group, batch_offset, shapemap);
+            applyResult(group, batch_offset, shapemap, wti);
 
             // Only the first pack group can be placed onto the print bed. The
             // other objects which could not fit will be placed next to the
@@ -823,10 +854,11 @@ bool arrange(Model &model,              // The model with the geometries
 void find_new_position(const Model &model,
                        ModelInstancePtrs toadd,
                        coord_t min_obj_distance,
-                       const Polyline &bed)
+                       const Polyline &bed,
+                       WipeTowerInfo& wti)
 {
     // Get the 2D projected shapes with their 3D model instance pointers
-    auto shapemap = arr::projectModelFromTop(model);
+    auto shapemap = arr::projectModelFromTop(model, wti);
 
     // Copy the references for the shapes only as the arranger expects a
     // sequence of objects convertible to Item or ClipperPolygon

src/libslic3r/ModelArrange.hpp

@@ -40,6 +40,13 @@ struct BedShapeHint {
 
 BedShapeHint bedShape(const Polyline& bed);
 
+struct WipeTowerInfo {
+    bool is_wipe_tower = false;
+    Vec2d pos;
+    Vec2d bb_size;
+    double rotation;
+};
+
 /**
  * \brief Arranges the model objects on the screen.
  *
@@ -66,7 +73,9 @@ BedShapeHint bedShape(const Polyline& bed);
  * packed. The unsigned argument is the number of items remaining to pack.
  * \param stopcondition A predicate returning true if abort is needed.
  */
-bool arrange(Model &model, coord_t min_obj_distance,
+bool arrange(Model &model,
+             WipeTowerInfo& wipe_tower_info,
+             coord_t min_obj_distance,
              const Slic3r::Polyline& bed,
              BedShapeHint bedhint,
              bool first_bin_only,
@@ -78,7 +87,8 @@ bool arrange(Model &model, coord_t min_obj_distance,
 void find_new_position(const Model& model,
                        ModelInstancePtrs instances_to_add,
                        coord_t min_obj_distance,
-                       const Slic3r::Polyline& bed);
+                       const Slic3r::Polyline& bed,
+                       WipeTowerInfo& wti);
 
 }   // arr
 }   // Slic3r

src/slic3r/GUI/3DScene.cpp

@@ -716,12 +716,12 @@ int GLVolumeCollection::load_wipe_tower_preview(
     brim_mesh.translate(-brim_width, -brim_width, 0.f);
     mesh.merge(brim_mesh);
 
-    mesh.rotate(rotation_angle, &origin_of_rotation); // rotates the box according to the config rotation setting
-
     this->volumes.emplace_back(new GLVolume(color));
     GLVolume &v = *this->volumes.back();
     v.indexed_vertex_array.load_mesh(mesh, use_VBOs);
     v.set_volume_offset(Vec3d(pos_x, pos_y, 0.0));
+    v.set_volume_rotation(Vec3d(0., 0., (M_PI/180.) * rotation_angle));
+
     // finalize_geometry() clears the vertex arrays, therefore the bounding box has to be computed before finalize_geometry().
     v.bounding_box = v.indexed_vertex_array.bounding_box();
     v.indexed_vertex_array.finalize_geometry(use_VBOs);

src/slic3r/GUI/GLCanvas3D.cpp

@@ -16,6 +16,7 @@
 #include "slic3r/GUI/GLShader.hpp"
 #include "slic3r/GUI/GUI.hpp"
 #include "slic3r/GUI/PresetBundle.hpp"
+#include "slic3r/GUI/Tab.hpp"
 #include "GUI_App.hpp"
 #include "GUI_ObjectList.hpp"
 #include "GUI_ObjectManipulation.hpp"
@@ -1202,6 +1203,7 @@ wxDEFINE_EVENT(EVT_GLCANVAS_INSTANCE_MOVED, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLCANVAS_INSTANCE_ROTATED, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLCANVAS_INSTANCE_SCALED, SimpleEvent);
 wxDEFINE_EVENT(EVT_GLCANVAS_WIPETOWER_MOVED, Vec3dEvent);
+wxDEFINE_EVENT(EVT_GLCANVAS_WIPETOWER_ROTATED, Vec3dEvent);
 wxDEFINE_EVENT(EVT_GLCANVAS_ENABLE_ACTION_BUTTONS, Event<bool>);
 wxDEFINE_EVENT(EVT_GLCANVAS_UPDATE_GEOMETRY, Vec3dsEvent<2>);
 wxDEFINE_EVENT(EVT_GLCANVAS_MOUSE_DRAGGING_FINISHED, SimpleEvent);
@@ -3116,6 +3118,10 @@ void GLCanvas3D::do_rotate()
     for (const GLVolume* v : m_volumes.volumes)
     {
         int object_idx = v->object_idx();
+        if (object_idx == 1000) { // the wipe tower
+            Vec3d offset = v->get_volume_offset();
+            post_event(Vec3dEvent(EVT_GLCANVAS_WIPETOWER_ROTATED, Vec3d(offset(0), offset(1), v->get_volume_rotation()(2))));
+        }
         if ((object_idx < 0) || ((int)m_model->objects.size() <= object_idx))
             continue;
 
@@ -3312,6 +3318,38 @@ void GLCanvas3D::update_ui_from_settings()
 #endif
 }
 
+
+
+arr::WipeTowerInfo GLCanvas3D::get_wipe_tower_info() const
+{
+    arr::WipeTowerInfo wti;
+    for (const GLVolume* vol : m_volumes.volumes) {
+        if (vol->is_wipe_tower) {
+            wti.is_wipe_tower = true;
+            wti.pos = Vec2d(m_config->opt_float("wipe_tower_x"),
+                            m_config->opt_float("wipe_tower_y"));
+            wti.rotation = (M_PI/180.) * m_config->opt_float("wipe_tower_rotation_angle");
+            const BoundingBoxf3& bb = vol->bounding_box;
+            wti.bb_size = Vec2d(bb.size()(0), bb.size()(1));
+            break;
+        }
+    }
+    return wti;
+}
+
+
+void GLCanvas3D::arrange_wipe_tower(const arr::WipeTowerInfo& wti) const
+{
+    if (wti.is_wipe_tower) {
+        DynamicPrintConfig cfg;
+        cfg.opt<ConfigOptionFloat>("wipe_tower_x", true)->value = wti.pos(0);
+        cfg.opt<ConfigOptionFloat>("wipe_tower_y", true)->value = wti.pos(1);
+        cfg.opt<ConfigOptionFloat>("wipe_tower_rotation_angle", true)->value = (180./M_PI) * wti.rotation;
+        wxGetApp().get_tab(Preset::TYPE_PRINT)->load_config(cfg);
+    }
+}
+
+
 Linef3 GLCanvas3D::mouse_ray(const Point& mouse_pos)
 {
     float z0 = 0.0f;
@@ -4315,6 +4353,7 @@ void GLCanvas3D::_render_selection_sidebar_hints() const
         m_shader.stop_using();
 }
 
+
 void GLCanvas3D::_update_volumes_hover_state() const
 {
     for (GLVolume* v : m_volumes.volumes)

src/slic3r/GUI/GLCanvas3D.hpp

@@ -4,6 +4,7 @@
 #include <stddef.h>
 #include <memory>
 
+#include "libslic3r/ModelArrange.hpp"
 #include "3DScene.hpp"
 #include "GLToolbar.hpp"
 #include "Event.hpp"
@@ -116,6 +117,7 @@ wxDECLARE_EVENT(EVT_GLCANVAS_INSTANCE_MOVED, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLCANVAS_WIPETOWER_MOVED, Vec3dEvent);
 wxDECLARE_EVENT(EVT_GLCANVAS_INSTANCE_ROTATED, SimpleEvent);
 wxDECLARE_EVENT(EVT_GLCANVAS_INSTANCE_SCALED, SimpleEvent);
+wxDECLARE_EVENT(EVT_GLCANVAS_WIPETOWER_ROTATED, Vec3dEvent);
 wxDECLARE_EVENT(EVT_GLCANVAS_ENABLE_ACTION_BUTTONS, Event<bool>);
 wxDECLARE_EVENT(EVT_GLCANVAS_UPDATE_GEOMETRY, Vec3dsEvent<2>);
 wxDECLARE_EVENT(EVT_GLCANVAS_MOUSE_DRAGGING_FINISHED, SimpleEvent);
@@ -608,6 +610,9 @@ public:
     int get_move_volume_id() const { return m_mouse.drag.move_volume_idx; }
     int get_first_hover_volume_idx() const { return m_hover_volume_idxs.empty() ? -1 : m_hover_volume_idxs.front(); }
 
+    arr::WipeTowerInfo get_wipe_tower_info() const;
+    void arrange_wipe_tower(const arr::WipeTowerInfo& wti) const;
+
     // Returns the view ray line, in world coordinate, at the given mouse position.
     Linef3 mouse_ray(const Point& mouse_pos);
 

src/slic3r/GUI/Gizmos/GLGizmoRotate.hpp

@@ -102,7 +102,7 @@ protected:
             m_gizmos[i].set_hover_id((m_hover_id == i) ? 0 : -1);
         }
     }
-    virtual bool on_is_activable(const Selection& selection) const { return !selection.is_wipe_tower(); }
+    virtual bool on_is_activable(const Selection& selection) const { return true; }
     virtual void on_enable_grabber(unsigned int id)
     {
         if ((0 <= id) && (id < 3))

src/slic3r/GUI/Gizmos/GLGizmosManager.cpp

@@ -4,6 +4,7 @@
 #include "slic3r/GUI/3DScene.hpp"
 #include "slic3r/GUI/GUI_App.hpp"
 #include "slic3r/GUI/GUI_ObjectManipulation.hpp"
+#include "slic3r/GUI/PresetBundle.hpp"
 
 #include <GL/glew.h>
 #include <wx/glcanvas.h>
@@ -264,8 +265,11 @@ void GLGizmosManager::update_data(GLCanvas3D& canvas)
 
     const Selection& selection = canvas.get_selection();
 
-    bool enable_move_z = !selection.is_wipe_tower();
-    enable_grabber(Move, 2, enable_move_z);
+    bool is_wipe_tower = selection.is_wipe_tower();
+    enable_grabber(Move, 2, !is_wipe_tower);
+    enable_grabber(Rotate, 0, !is_wipe_tower);
+    enable_grabber(Rotate, 1, !is_wipe_tower);
+
     bool enable_scale_xyz = selection.is_single_full_instance() || selection.is_single_volume() || selection.is_single_modifier();
     for (int i = 0; i < 6; ++i)
     {
@@ -290,6 +294,14 @@ void GLGizmosManager::update_data(GLCanvas3D& canvas)
         set_flattening_data(nullptr);
         set_sla_support_data(nullptr, selection);
     }
+    else if (is_wipe_tower)
+    {
+        DynamicPrintConfig& config = wxGetApp().preset_bundle->prints.get_edited_preset().config;
+        set_scale(Vec3d::Ones());
+        set_rotation(Vec3d(0., 0., (M_PI/180.) * dynamic_cast<const ConfigOptionFloat*>(config.option("wipe_tower_rotation_angle"))->value));
+        set_flattening_data(nullptr);
+        set_sla_support_data(nullptr, selection);
+    }
     else
     {
         set_scale(Vec3d::Ones());

src/slic3r/GUI/Plater.cpp

@@ -1314,6 +1314,7 @@ struct Plater::priv
     void on_object_select(SimpleEvent&);
     void on_right_click(Vec2dEvent&);
     void on_wipetower_moved(Vec3dEvent&);
+    void on_wipetower_rotated(Vec3dEvent&);
     void on_update_geometry(Vec3dsEvent<2>&);
     void on_3dcanvas_mouse_dragging_finished(SimpleEvent&);
 
@@ -1448,6 +1449,7 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame)
         { if (evt.data == 1) this->q->increase_instances(); else if (this->can_decrease_instances()) this->q->decrease_instances(); });
     view3D_canvas->Bind(EVT_GLCANVAS_INSTANCE_MOVED, [this](SimpleEvent&) { update(); });
     view3D_canvas->Bind(EVT_GLCANVAS_WIPETOWER_MOVED, &priv::on_wipetower_moved, this);
+    view3D_canvas->Bind(EVT_GLCANVAS_WIPETOWER_ROTATED, &priv::on_wipetower_rotated, this);
     view3D_canvas->Bind(EVT_GLCANVAS_INSTANCE_ROTATED, [this](SimpleEvent&) { update(); });
     view3D_canvas->Bind(EVT_GLCANVAS_INSTANCE_SCALED, [this](SimpleEvent&) { update(); });
     view3D_canvas->Bind(EVT_GLCANVAS_ENABLE_ACTION_BUTTONS, [this](Event<bool> &evt) { this->sidebar->enable_buttons(evt.data); });
@@ -1455,6 +1457,7 @@ Plater::priv::priv(Plater *q, MainFrame *main_frame)
     view3D_canvas->Bind(EVT_GLCANVAS_MOUSE_DRAGGING_FINISHED, &priv::on_3dcanvas_mouse_dragging_finished, this);
     view3D_canvas->Bind(EVT_GLCANVAS_TAB, [this](SimpleEvent&) { select_next_view_3D(); });
     view3D_canvas->Bind(EVT_GLCANVAS_RESETGIZMOS, [this](SimpleEvent&) { reset_all_gizmos(); });
+
     // 3DScene/Toolbar:
     view3D_canvas->Bind(EVT_GLTOOLBAR_ADD, &priv::on_action_add, this);
     view3D_canvas->Bind(EVT_GLTOOLBAR_DELETE, [q](SimpleEvent&) { q->remove_selected(); });
@@ -1877,7 +1880,13 @@ std::vector<size_t> Plater::priv::load_model_objects(const ModelObjectPtrs &mode
     Polyline bed; bed.points.reserve(bedpoints.size());
     for(auto& v : bedpoints) bed.append(Point::new_scale(v(0), v(1)));
 
-    arr::find_new_position(model, new_instances, min_obj_distance, bed);
+    arr::WipeTowerInfo wti = view3D->get_canvas3d()->get_wipe_tower_info();
+
+    arr::find_new_position(model, new_instances, min_obj_distance, bed, wti);
+
+    // it remains to move the wipe tower:
+    view3D->get_canvas3d()->arrange_wipe_tower(wti);
+
 #endif /* AUTOPLACEMENT_ON_LOAD */
 
     if (scaled_down) {
@@ -2134,6 +2143,8 @@ void Plater::priv::arrange()
 
     statusfn(0, arrangestr);
 
+    arr::WipeTowerInfo wti = view3D->get_canvas3d()->get_wipe_tower_info();
+
     try {
         arr::BedShapeHint hint;
 
@@ -2141,6 +2152,7 @@ void Plater::priv::arrange()
         hint.type = arr::BedShapeType::WHO_KNOWS;
 
         arr::arrange(model,
+                     wti,
                      min_obj_distance,
                      bed,
                      hint,
@@ -2152,6 +2164,9 @@ void Plater::priv::arrange()
                                    "Some geometries may be invalid."));
     }
 
+    // it remains to move the wipe tower:
+    view3D->get_canvas3d()->arrange_wipe_tower(wti);
+
     statusfn(0, L("Arranging done."));
     statusbar()->set_range(prev_range);
     statusbar()->set_cancel_callback(); // remove cancel button
@@ -2254,7 +2269,8 @@ void Plater::priv::sla_optimize_rotation() {
         oi->set_rotation(rt);
     }
 
-    arr::find_new_position(model, o->instances, coord_t(mindist/SCALING_FACTOR), bed);
+    arr::WipeTowerInfo wti; // useless in SLA context
+    arr::find_new_position(model, o->instances, coord_t(mindist/SCALING_FACTOR), bed, wti);
 
     // Correct the z offset of the object which was corrupted be the rotation
     o->ensure_on_bed();
@@ -2862,6 +2878,15 @@ void Plater::priv::on_wipetower_moved(Vec3dEvent &evt)
     wxGetApp().get_tab(Preset::TYPE_PRINT)->load_config(cfg);
 }
 
+void Plater::priv::on_wipetower_rotated(Vec3dEvent& evt)
+{
+    DynamicPrintConfig cfg;
+    cfg.opt<ConfigOptionFloat>("wipe_tower_x", true)->value = evt.data(0);
+    cfg.opt<ConfigOptionFloat>("wipe_tower_y", true)->value = evt.data(1);
+    cfg.opt<ConfigOptionFloat>("wipe_tower_rotation_angle", true)->value = Geometry::rad2deg(evt.data(2));
+    wxGetApp().get_tab(Preset::TYPE_PRINT)->load_config(cfg);
+}
+
 void Plater::priv::on_update_geometry(Vec3dsEvent<2>&)
 {
     // TODO

src/slic3r/GUI/Selection.cpp

@@ -499,100 +499,111 @@ void Selection::rotate(const Vec3d& rotation, TransformationType transformation_
     // Only relative rotation values are allowed in the world coordinate system.
     assert(!transformation_type.world() || transformation_type.relative());
 
-    int rot_axis_max = 0;
-    if (rotation.isApprox(Vec3d::Zero()))
-    {
-        for (unsigned int i : m_list)
+    if (!is_wipe_tower()) {
+        int rot_axis_max = 0;
+        if (rotation.isApprox(Vec3d::Zero()))
         {
-            GLVolume &volume = *(*m_volumes)[i];
-            if (m_mode == Instance)
-            {
-                volume.set_instance_rotation(m_cache.volumes_data[i].get_instance_rotation());
-                volume.set_instance_offset(m_cache.volumes_data[i].get_instance_position());
-            }
-            else if (m_mode == Volume)
-            {
-                volume.set_volume_rotation(m_cache.volumes_data[i].get_volume_rotation());
-                volume.set_volume_offset(m_cache.volumes_data[i].get_volume_position());
-            }
-        }
-    }
-    else
-    {
-        //FIXME this does not work for absolute rotations (transformation_type.absolute() is true)
-        rotation.cwiseAbs().maxCoeff(&rot_axis_max);
-
-        // For generic rotation, we want to rotate the first volume in selection, and then to synchronize the other volumes with it.
-        std::vector<int> object_instance_first(m_model->objects.size(), -1);
-        auto rotate_instance = [this, &rotation, &object_instance_first, rot_axis_max, transformation_type](GLVolume &volume, int i) {
-            int first_volume_idx = object_instance_first[volume.object_idx()];
-            if (rot_axis_max != 2 && first_volume_idx != -1) {
-                // Generic rotation, but no rotation around the Z axis.
-                // Always do a local rotation (do not consider the selection to be a rigid body).
-                assert(is_approx(rotation.z(), 0.0));
-                const GLVolume &first_volume = *(*m_volumes)[first_volume_idx];
-                const Vec3d    &rotation = first_volume.get_instance_rotation();
-                double z_diff = Geometry::rotation_diff_z(m_cache.volumes_data[first_volume_idx].get_instance_rotation(), m_cache.volumes_data[i].get_instance_rotation());
-                volume.set_instance_rotation(Vec3d(rotation(0), rotation(1), rotation(2) + z_diff));
-            }
-            else {
-                // extracts rotations from the composed transformation
-                Vec3d new_rotation = transformation_type.world() ?
-                    Geometry::extract_euler_angles(Geometry::assemble_transform(Vec3d::Zero(), rotation) * m_cache.volumes_data[i].get_instance_rotation_matrix()) :
-                    transformation_type.absolute() ? rotation : rotation + m_cache.volumes_data[i].get_instance_rotation();
-                if (rot_axis_max == 2 && transformation_type.joint()) {
-                    // Only allow rotation of multiple instances as a single rigid body when rotating around the Z axis.
-                    Vec3d offset = Geometry::assemble_transform(Vec3d::Zero(), Vec3d(0.0, 0.0, new_rotation(2) - m_cache.volumes_data[i].get_instance_rotation()(2))) * (m_cache.volumes_data[i].get_instance_position() - m_cache.dragging_center);
-                    volume.set_instance_offset(m_cache.dragging_center + offset);
-                }
-                volume.set_instance_rotation(new_rotation);
-                object_instance_first[volume.object_idx()] = i;
-            }
-        };
-
-        for (unsigned int i : m_list)
-        {
-            GLVolume &volume = *(*m_volumes)[i];
-            if (is_single_full_instance())
-                rotate_instance(volume, i);
-            else if (is_single_volume() || is_single_modifier())
-            {
-                if (transformation_type.independent())
-                    volume.set_volume_rotation(volume.get_volume_rotation() + rotation);
-                else
-                {
-                    Transform3d m = Geometry::assemble_transform(Vec3d::Zero(), rotation);
-                    Vec3d new_rotation = Geometry::extract_euler_angles(m * m_cache.volumes_data[i].get_volume_rotation_matrix());
-                    volume.set_volume_rotation(new_rotation);
-                }
-            }
-            else
+            for (unsigned int i : m_list)
             {
+                GLVolume &volume = *(*m_volumes)[i];
                 if (m_mode == Instance)
-                    rotate_instance(volume, i);
+                {
+                    volume.set_instance_rotation(m_cache.volumes_data[i].get_instance_rotation());
+                    volume.set_instance_offset(m_cache.volumes_data[i].get_instance_position());
+                }
                 else if (m_mode == Volume)
                 {
-                    // extracts rotations from the composed transformation
-                    Transform3d m = Geometry::assemble_transform(Vec3d::Zero(), rotation);
-                    Vec3d new_rotation = Geometry::extract_euler_angles(m * m_cache.volumes_data[i].get_volume_rotation_matrix());
-                    if (transformation_type.joint())
-                    {
-                        Vec3d local_pivot = m_cache.volumes_data[i].get_instance_full_matrix().inverse() * m_cache.dragging_center;
-                        Vec3d offset = m * (m_cache.volumes_data[i].get_volume_position() - local_pivot);
-                        volume.set_volume_offset(local_pivot + offset);
-                    }
-                    volume.set_volume_rotation(new_rotation);
+                    volume.set_volume_rotation(m_cache.volumes_data[i].get_volume_rotation());
+                    volume.set_volume_offset(m_cache.volumes_data[i].get_volume_position());
                 }
             }
         }
-    }
+        else { // this is not the wipe tower
+            //FIXME this does not work for absolute rotations (transformation_type.absolute() is true)
+            rotation.cwiseAbs().maxCoeff(&rot_axis_max);
 
-#if !DISABLE_INSTANCES_SYNCH
-    if (m_mode == Instance)
-        synchronize_unselected_instances((rot_axis_max == 2) ? SYNC_ROTATION_NONE : SYNC_ROTATION_GENERAL);
-    else if (m_mode == Volume)
-        synchronize_unselected_volumes();
-#endif // !DISABLE_INSTANCES_SYNCH
+            // For generic rotation, we want to rotate the first volume in selection, and then to synchronize the other volumes with it.
+            std::vector<int> object_instance_first(m_model->objects.size(), -1);
+            auto rotate_instance = [this, &rotation, &object_instance_first, rot_axis_max, transformation_type](GLVolume &volume, int i) {
+                int first_volume_idx = object_instance_first[volume.object_idx()];
+                if (rot_axis_max != 2 && first_volume_idx != -1) {
+                    // Generic rotation, but no rotation around the Z axis.
+                    // Always do a local rotation (do not consider the selection to be a rigid body).
+                    assert(is_approx(rotation.z(), 0.0));
+                    const GLVolume &first_volume = *(*m_volumes)[first_volume_idx];
+                    const Vec3d    &rotation = first_volume.get_instance_rotation();
+                    double z_diff = Geometry::rotation_diff_z(m_cache.volumes_data[first_volume_idx].get_instance_rotation(), m_cache.volumes_data[i].get_instance_rotation());
+                    volume.set_instance_rotation(Vec3d(rotation(0), rotation(1), rotation(2) + z_diff));
+                }
+                else {
+                    // extracts rotations from the composed transformation
+                    Vec3d new_rotation = transformation_type.world() ?
+                        Geometry::extract_euler_angles(Geometry::assemble_transform(Vec3d::Zero(), rotation) * m_cache.volumes_data[i].get_instance_rotation_matrix()) :
+                        transformation_type.absolute() ? rotation : rotation + m_cache.volumes_data[i].get_instance_rotation();
+                    if (rot_axis_max == 2 && transformation_type.joint()) {
+                        // Only allow rotation of multiple instances as a single rigid body when rotating around the Z axis.
+                        Vec3d offset = Geometry::assemble_transform(Vec3d::Zero(), Vec3d(0.0, 0.0, new_rotation(2) - m_cache.volumes_data[i].get_instance_rotation()(2))) * (m_cache.volumes_data[i].get_instance_position() - m_cache.dragging_center);
+                        volume.set_instance_offset(m_cache.dragging_center + offset);
+                    }
+                    volume.set_instance_rotation(new_rotation);
+                    object_instance_first[volume.object_idx()] = i;
+                }
+            };
+
+            for (unsigned int i : m_list)
+            {
+                GLVolume &volume = *(*m_volumes)[i];
+                if (is_single_full_instance())
+                    rotate_instance(volume, i);
+                else if (is_single_volume() || is_single_modifier())
+                {
+                    if (transformation_type.independent())
+                        volume.set_volume_rotation(volume.get_volume_rotation() + rotation);
+                    else
+                    {
+                        Transform3d m = Geometry::assemble_transform(Vec3d::Zero(), rotation);
+                        Vec3d new_rotation = Geometry::extract_euler_angles(m * m_cache.volumes_data[i].get_volume_rotation_matrix());
+                        volume.set_volume_rotation(new_rotation);
+                    }
+                }
+                else
+                {
+                    if (m_mode == Instance)
+                        rotate_instance(volume, i);
+                    else if (m_mode == Volume)
+                    {
+                        // extracts rotations from the composed transformation
+                        Transform3d m = Geometry::assemble_transform(Vec3d::Zero(), rotation);
+                        Vec3d new_rotation = Geometry::extract_euler_angles(m * m_cache.volumes_data[i].get_volume_rotation_matrix());
+                        if (transformation_type.joint())
+                        {
+                            Vec3d local_pivot = m_cache.volumes_data[i].get_instance_full_matrix().inverse() * m_cache.dragging_center;
+                            Vec3d offset = m * (m_cache.volumes_data[i].get_volume_position() - local_pivot);
+                            volume.set_volume_offset(local_pivot + offset);
+                        }
+                        volume.set_volume_rotation(new_rotation);
+                    }
+                }
+            }
+        }
+
+    #if !DISABLE_INSTANCES_SYNCH
+        if (m_mode == Instance)
+            synchronize_unselected_instances((rot_axis_max == 2) ? SYNC_ROTATION_NONE : SYNC_ROTATION_GENERAL);
+        else if (m_mode == Volume)
+            synchronize_unselected_volumes();
+    #endif // !DISABLE_INSTANCES_SYNCH
+    }
+    else { // it's the wipe tower that's selected and being rotated
+        GLVolume& volume = *((*m_volumes)[*m_list.begin()]); // the wipe tower is always alone in the selection
+
+        // make sure the wipe tower rotates around its center, not origin
+        // we can assume that only Z rotation changes
+        Vec3d center_local = volume.transformed_bounding_box().center() - volume.get_volume_offset();
+        Vec3d center_local_new = Eigen::AngleAxisd(rotation(2)-volume.get_volume_rotation()(2), Vec3d(0, 0, 1)) * center_local;
+        volume.set_volume_rotation(rotation);
+        volume.set_volume_offset(volume.get_volume_offset() + center_local - center_local_new);
+    }
 
     this->set_bounding_boxes_dirty();
 }