Fix wrong z when zhop is diabled.

src/libslic3r/GCode.cpp

@@ -729,7 +729,6 @@ static std::vector<Vec2d> get_path_of_change_filament(const Print& print)
         gcode += gcodegen.writer().unlift(); // Make sure there is no z-hop (in most cases, there isn't).
 
         double current_z = gcodegen.writer().get_position().z();
-        gcode += gcodegen.writer().travel_to_z(current_z);
 
 
         if (z == -1.) // in case no specific z was provided, print at current_z pos
@@ -6006,14 +6005,15 @@ std::string GCode::travel_to(const Point& point, ExtrusionRole role, std::string
         if (m_spiral_vase) {
             // No lazy z lift for spiral vase mode
             for (size_t i = 1; i < travel.size(); ++i) {
-                gcode += m_writer.travel_to_xy(this->point_to_gcode(travel.points[i]), comment + " travel_to_xy");
+                gcode += m_writer.travel_to_xy(this->point_to_gcode(travel.points[i]), comment);
             }
         } else {
             if (travel.size() == 2) {
                 // No extra movements emitted by avoid_crossing_perimeters, simply move to the end point with z change
                 const auto& dest2d = this->point_to_gcode(travel.points.back());
                 Vec3d dest3d(dest2d(0), dest2d(1), z == DBL_MAX ? m_writer.get_position().z() : z);
-                gcode += m_writer.travel_to_xyz(dest3d, comment + " travel_to_xyz");
+                gcode += m_writer.travel_to_xyz(dest3d, comment, m_need_change_layer_lift_z);
+                m_need_change_layer_lift_z = false;
             } else {
                 // Extra movements emitted by avoid_crossing_perimeters, lift the z to normal height at the beginning, then apply the z
                 // ratio at the last point
@@ -6022,25 +6022,22 @@ std::string GCode::travel_to(const Point& point, ExtrusionRole role, std::string
                         // Lift to normal z at beginning
                         Vec2d dest2d = this->point_to_gcode(travel.points[i]);
                         Vec3d dest3d(dest2d(0), dest2d(1), m_writer.get_position().z());
-                        gcode += m_writer.travel_to_xyz(dest3d, comment + " travel_to_xyz");
+                        gcode += m_writer.travel_to_xyz(dest3d, comment, m_need_change_layer_lift_z);
+                        m_need_change_layer_lift_z = false;
                     } else if (z != DBL_MAX && i == travel.size() - 1) {
                         // Apply z_ratio for the very last point
                         Vec2d dest2d = this->point_to_gcode(travel.points[i]);
                         Vec3d dest3d(dest2d(0), dest2d(1), z);
-                        gcode += m_writer.travel_to_xyz(dest3d, comment + " travel_to_xyz");
+                        gcode += m_writer.travel_to_xyz(dest3d, comment);
                     } else {
                         // For all points in between, no z change
-                        gcode += m_writer.travel_to_xy(this->point_to_gcode(travel.points[i]), comment + " travel_to_xy");
+                        gcode += m_writer.travel_to_xy(this->point_to_gcode(travel.points[i]), comment);
                     }
                 }
             }
         }
         this->set_last_pos(travel.points.back());
     }
-    if (m_need_change_layer_lift_z) {
-        gcode += m_writer._travel_to_z(m_writer.get_position().z(), comment + " travel_to_z");
-        m_need_change_layer_lift_z = false;
-    }
 
     return gcode;
 }

src/libslic3r/GCodeWriter.cpp

@@ -440,7 +440,7 @@ std::string GCodeWriter::travel_to_xy(const Vec2d &point, const std::string &com
     return w.string();
 }
 
-std::string GCodeWriter::travel_to_xyz(const Vec3d &point, const std::string &comment)
+std::string GCodeWriter::travel_to_xyz(const Vec3d &point, const std::string &comment, bool force_z)
 {
     // FIXME: This function was not being used when travel_speed_z was separated (bd6badf).
     // Calculation of feedrate was not updated accordingly. If you want to use
@@ -526,7 +526,7 @@ std::string GCodeWriter::travel_to_xyz(const Vec3d &point, const std::string &co
         this->set_current_position_clear(true);
         return slop_move + xy_z_move;
     }
-    else if (!this->will_move_z(point(2))) {
+    else if (!force_z && !this->will_move_z(point(2))) {
         double nominal_z = m_pos(2) - m_lifted;
         m_lifted -= (point(2) - nominal_z);
         // In case that z_hop == layer_height we could end up with almost zero in_m_lifted

src/libslic3r/GCodeWriter.hpp

@@ -69,7 +69,7 @@ public:
     // SoftFever NOTE: the returned speed is mm/minute
     double      get_current_speed() const { return m_current_speed;}
     std::string travel_to_xy(const Vec2d &point, const std::string &comment = std::string());
-    std::string travel_to_xyz(const Vec3d &point, const std::string &comment = std::string());
+    std::string travel_to_xyz(const Vec3d &point, const std::string &comment = std::string(), bool force_z = false);
     std::string travel_to_z(double z, const std::string &comment = std::string());
     bool        will_move_z(double z) const;
     std::string extrude_to_xy(const Vec2d &point, double dE, const std::string &comment = std::string(), bool force_no_extrusion = false);
@@ -119,7 +119,6 @@ public:
 
     // Returns whether this flavor supports separate print and travel acceleration.
     static bool supports_separate_travel_acceleration(GCodeFlavor flavor);
-    std::string _travel_to_z(double z, const std::string &comment);
   private:
 	// Extruders are sorted by their ID, so that binary search is possible.
     std::vector<Extruder> m_extruders;
@@ -173,6 +172,7 @@ public:
         Print
     };
 
+    std::string _travel_to_z(double z, const std::string &comment);
     std::string _spiral_travel_to_z(double z, const Vec2d &ij_offset, const std::string &comment);
     std::string _retract(double length, double restart_extra, const std::string &comment);
     std::string set_acceleration_internal(Acceleration type, unsigned int acceleration);