Simplified loading of the SLA support structures into the scene.

Fixed referesh of SLA support structures after Undo / Redo
and when moving an object outside / inside the build volume.

src/slic3r/GUI/GLCanvas3D.cpp

@@ -1858,6 +1858,10 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
     PrinterTechnology printer_technology        = m_process->current_printer_technology();
     int               volume_idx_wipe_tower_old = -1;
 
+    if (printer_technology == ptSLA)
+    	// Always do the full refresh in SLA mode to show / hide SLA support structures when an object is moved outside / inside the build volume.
+    	m_regenerate_volumes = true;
+
     if (m_regenerate_volumes)
     {
         // Release invalidated volumes to conserve GPU memory in case of delayed refresh (see m_reload_delayed).
@@ -1890,7 +1894,10 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
                             state.step[istep].state = PrintStateBase::INVALID;
                         else
     						for (const ModelInstance *model_instance : print_object->model_object()->instances)
-                                aux_volume_state.emplace_back(state.step[istep].timestamp, model_instance->id());
+    							// Only the instances, which are currently printable, will have the SLA support structures kept.
+    							// The instances outside the print bed will have the GLVolumes of their support structures released.
+    							if (model_instance->is_printable())
+                                	aux_volume_state.emplace_back(state.step[istep].timestamp, model_instance->id());
                     }
 				}
 				sla_support_state.emplace_back(state);
@@ -2042,7 +2049,8 @@ void GLCanvas3D::reload_scene(bool refresh_immediately, bool force_full_scene_re
 
 			// Shift-up all volumes of the object so that it has the right elevation with respect to the print bed
 			for (GLVolume* volume : m_volumes.volumes)
-				volume->set_sla_shift_z(shift_zs[volume->object_idx()]);
+				if (volume->object_idx() < m_model->objects.size() && m_model->objects[volume->object_idx()]->instances[volume->instance_idx()]->is_printable())
+					volume->set_sla_shift_z(shift_zs[volume->object_idx()]);
         }
 
         if (printer_technology == ptFFF && m_config->has("nozzle_diameter"))
@@ -2198,7 +2206,8 @@ void GLCanvas3D::load_sla_preview()
     if ((m_canvas != nullptr) && (print != nullptr))
     {
         _set_current();
-        _load_sla_shells();
+        // Reload the SLA support structures into GLVolumes.
+		this->reload_scene(true, true);
         _update_sla_shells_outside_state();
         _show_warning_texture_if_needed(WarningTexture::SlaSupportsOutside);
     }
@@ -5461,56 +5470,6 @@ void GLCanvas3D::_load_fff_shells()
     }
 }
 
-void GLCanvas3D::_load_sla_shells()
-{
-    //FIXME use reload_scene
-#if 1
-    const SLAPrint* print = this->sla_print();
-    if (print->objects().empty())
-        // nothing to render, return
-        return;
-
-    auto add_volume = [this](const SLAPrintObject &object, int volume_id, const SLAPrintObject::Instance& instance,
-        const TriangleMesh &mesh, const float color[4], bool outside_printer_detection_enabled) {
-        m_volumes.volumes.emplace_back(new GLVolume(color));
-        GLVolume& v = *m_volumes.volumes.back();
-        v.indexed_vertex_array.load_mesh(mesh);
-        v.shader_outside_printer_detection_enabled = outside_printer_detection_enabled;
-        v.composite_id.volume_id = volume_id;
-        v.set_instance_offset(unscale(instance.shift(0), instance.shift(1), 0));
-        v.set_instance_rotation(Vec3d(0.0, 0.0, (double)instance.rotation));
-        v.set_instance_mirror(X, object.is_left_handed() ? -1. : 1.);
-        v.set_convex_hull(mesh.convex_hull_3d());
-    };
-
-    // adds objects' volumes 
-    for (const SLAPrintObject* obj : print->objects())
-        if (obj->is_step_done(slaposSliceSupports)) {
-            unsigned int initial_volumes_count = (unsigned int)m_volumes.volumes.size();
-            for (const SLAPrintObject::Instance& instance : obj->instances()) {
-                add_volume(*obj, 0, instance, obj->transformed_mesh(), GLVolume::MODEL_COLOR[0], true);
-                // Set the extruder_id and volume_id to achieve the same color as in the 3D scene when
-                // through the update_volumes_colors_by_extruder() call.
-                m_volumes.volumes.back()->extruder_id = obj->model_object()->volumes.front()->extruder_id();
-                if (obj->is_step_done(slaposSupportTree) && obj->has_mesh(slaposSupportTree))
-                    add_volume(*obj, -int(slaposSupportTree), instance, obj->support_mesh(), GLVolume::SLA_SUPPORT_COLOR, true);
-                if (obj->is_step_done(slaposBasePool) && obj->has_mesh(slaposBasePool))
-                    add_volume(*obj, -int(slaposBasePool), instance, obj->pad_mesh(), GLVolume::SLA_PAD_COLOR, false);
-            }
-            double shift_z = obj->get_current_elevation();
-            for (unsigned int i = initial_volumes_count; i < m_volumes.volumes.size(); ++ i) {
-                GLVolume& v = *m_volumes.volumes[i];
-                // apply shift z
-                v.set_sla_shift_z(shift_z);
-            }
-        }
-
-    update_volumes_colors_by_extruder();
-#else
-    this->reload_scene(true, true);
-#endif
-}
-
 void GLCanvas3D::_update_gcode_volumes_visibility(const GCodePreviewData& preview_data)
 {
     unsigned int size = (unsigned int)m_gcode_preview_volume_index.first_volumes.size();

src/slic3r/GUI/GLCanvas3D.hpp

@@ -730,8 +730,6 @@ private:
     void _load_gcode_unretractions(const GCodePreviewData& preview_data);
     // generates objects and wipe tower geometry
     void _load_fff_shells();
-    // generates objects geometry for sla
-    void _load_sla_shells();
     // sets gcode geometry visibility according to user selection
     void _update_gcode_volumes_visibility(const GCodePreviewData& preview_data);
     void _update_toolpath_volumes_outside_state();