SPE-2501: Add an option to specify which extruder controls the bed temperature.

src/libslic3r/GCode.cpp

@@ -1215,7 +1215,7 @@ void GCodeGenerator::_do_export(Print& print, GCodeOutputStream &file, Thumbnail
     // Enable ooze prevention if configured so.
     DoExport::init_ooze_prevention(print, m_ooze_prevention);
 
-    std::string start_gcode = this->placeholder_parser_process("start_gcode", print.config().start_gcode.value, initial_extruder_id);
+    const std::string start_gcode = this->_process_start_gcode(print, initial_extruder_id);
 
     this->_print_first_layer_chamber_temperature(file, print, start_gcode, config().chamber_temperature.get_at(initial_extruder_id), false, false);
     this->_print_first_layer_bed_temperature(file, print, start_gcode, initial_extruder_id, true);
@@ -1888,15 +1888,34 @@ void GCodeGenerator::print_machine_envelope(GCodeOutputStream &file, const Print
     }
 }
 
+std::string GCodeGenerator::_process_start_gcode(const Print& print, unsigned int current_extruder_id)
+{
+    const int num_extruders            = print.config().nozzle_diameter.values.size();
+    const int bed_temperature_extruder = print.config().bed_temperature_extruder;
+    if (0 < bed_temperature_extruder && bed_temperature_extruder <= num_extruders) {
+        const int first_layer_bed_temperature = print.config().first_layer_bed_temperature.get_at(bed_temperature_extruder - 1);
+        DynamicConfig config;
+        config.set_key_value("first_layer_bed_temperature", new ConfigOptionInts(num_extruders, first_layer_bed_temperature));
+        return this->placeholder_parser_process("start_gcode", print.config().start_gcode.value, current_extruder_id, &config);
+    } else {
+        return this->placeholder_parser_process("start_gcode", print.config().start_gcode.value, current_extruder_id);
+    }
+}
+
 // Write 1st layer bed temperatures into the G-code.
 // Only do that if the start G-code does not already contain any M-code controlling an extruder temperature.
 // M140 - Set Extruder Temperature
 // M190 - Set Extruder Temperature and Wait
 void GCodeGenerator::_print_first_layer_bed_temperature(GCodeOutputStream &file, const Print &print, const std::string &gcode, unsigned int first_printing_extruder_id, bool wait)
 {
-    bool autoemit = print.config().autoemit_temperature_commands;
-    // Initial bed temperature based on the first extruder.
-    int  temp = print.config().first_layer_bed_temperature.get_at(first_printing_extruder_id);
+    const bool autoemit                    = print.config().autoemit_temperature_commands;
+    const int  num_extruders               = print.config().nozzle_diameter.values.size();
+    const int  bed_temperature_extruder    = print.config().bed_temperature_extruder;
+    const bool use_first_printing_extruder = bed_temperature_extruder <= 0 || bed_temperature_extruder > num_extruders;
+
+    // Initial bed temperature based on the first printing extruder or based on the extruded in bed_temperature_extruder.
+    int temp = print.config().first_layer_bed_temperature.get_at(use_first_printing_extruder ? first_printing_extruder_id : bed_temperature_extruder - 1);
+
     // Is the bed temperature set by the provided custom G-code?
     int  temp_by_gcode     = -1;
     bool temp_set_by_gcode = custom_gcode_sets_temperature(gcode, 140, 190, false, temp_by_gcode);
@@ -2646,7 +2665,15 @@ LayerResult GCodeGenerator::process_layer(
             if (temperature > 0 && (temperature != print.config().first_layer_temperature.get_at(extruder.id())))
                 gcode += m_writer.set_temperature(temperature, false, extruder.id());
         }
-        gcode += m_writer.set_bed_temperature(print.config().bed_temperature.get_at(first_extruder_id));
+
+        // Bed temperature for layers from the 2nd layer is based on the first printing
+        // extruder on the layer or on the extruded in bed_temperature_extruder.
+        const int  num_extruders            = print.config().nozzle_diameter.values.size();
+        const int  bed_temperature_extruder = print.config().bed_temperature_extruder;
+        const bool use_first_extruder       = bed_temperature_extruder <= 0 || bed_temperature_extruder > num_extruders;
+        const int  bed_temperature          = print.config().bed_temperature.get_at(use_first_extruder ? first_extruder_id : bed_temperature_extruder - 1);
+        gcode += m_writer.set_bed_temperature(bed_temperature);
+
         // Mark the temperature transition from 1st to 2nd layer to be finished.
         m_second_layer_things_done = true;
     }

src/libslic3r/GCode.hpp

@@ -494,6 +494,7 @@ private:
     std::string                         _extrude(const ExtrusionAttributes &attribs, const Geometry::ArcWelder::Path &path, std::string_view description, double speed, const EmitModifiers &emit_modifiers = EmitModifiers());
 
     void                                print_machine_envelope(GCodeOutputStream &file, const Print &print);
+    std::string                         _process_start_gcode(const Print &print, unsigned int current_extruder_id);
     void                                _print_first_layer_chamber_temperature(GCodeOutputStream &file, const Print &print, const std::string &gcode, int temp, bool wait, bool accurate);
     void                                _print_first_layer_bed_temperature(GCodeOutputStream &file, const Print &print, const std::string &gcode, unsigned int first_printing_extruder_id, bool wait);
     void                                _print_first_layer_extruder_temperatures(GCodeOutputStream &file, const Print &print, const std::string &gcode, unsigned int first_printing_extruder_id, bool wait);

src/libslic3r/Preset.cpp

@@ -511,6 +511,7 @@ static std::vector<std::string> s_Preset_print_options {
     "wall_distribution_count", "min_feature_size", "min_bead_width",
     "top_one_perimeter_type", "only_one_perimeter_first_layer",
     "automatic_extrusion_widths", "automatic_infill_combination", "automatic_infill_combination_max_layer_height",
+    "bed_temperature_extruder"
 };
 
 static std::vector<std::string> s_Preset_filament_options {

src/libslic3r/PrintConfig.cpp

@@ -618,6 +618,16 @@ void PrintConfigDef::init_fff_params()
     def->mode = comExpert;
     def->set_default_value(new ConfigOptionInts{ 0 });
 
+    def = this->add("bed_temperature_extruder", coInt);
+    def->label = L("Bed temperature by extruder");
+    def->category = L("Extruders");
+    def->tooltip = L("The extruder which determines bed temperatures. "
+                     "Set to 0 to determine temperatures based on the first printing extruder "
+                     "of the first and the second layers.");
+    def->min = 0;
+    def->mode = comAdvanced;
+    def->set_default_value(new ConfigOptionInt(0));
+
     def = this->add("before_layer_gcode", coString);
     def->label = L("Before layer change G-code");
     def->tooltip = L("This custom code is inserted at every layer change, right before the Z move. "
@@ -5162,6 +5172,16 @@ void DynamicPrintConfig::normalize_fdm()
     if (!this->has("solid_infill_extruder") && this->has("infill_extruder"))
         this->option("solid_infill_extruder", true)->setInt(this->option("infill_extruder")->getInt());
 
+    if (this->has("bed_temperature_extruder")) {
+        const size_t num_extruders = this->opt<ConfigOptionFloats>("nozzle_diameter")->size();
+        const int    extruder      = this->opt<ConfigOptionInt>("bed_temperature_extruder")->value;
+
+        // Replace invalid values with 0.
+        if (extruder < 0 || extruder > num_extruders) {
+            this->option("bed_temperature_extruder")->setInt(0);
+        }
+    }
+
     if (this->has("spiral_vase") && this->opt<ConfigOptionBool>("spiral_vase", true)->value) {
         {
             // this should be actually done only on the spiral layers instead of all

src/libslic3r/PrintConfig.hpp

@@ -798,6 +798,7 @@ PRINT_CONFIG_CLASS_DEFINE(
 
     ((ConfigOptionEnum<ArcFittingType>, arc_fitting))
     ((ConfigOptionBool,                autoemit_temperature_commands))
+    ((ConfigOptionInt,                 bed_temperature_extruder))
     ((ConfigOptionString,              before_layer_gcode))
     ((ConfigOptionString,              between_objects_gcode))
     ((ConfigOptionBool,                binary_gcode))

src/slic3r/GUI/Tab.cpp

@@ -1635,6 +1635,7 @@ void TabPrint::build()
         optgroup->append_single_option_line("support_material_extruder");
         optgroup->append_single_option_line("support_material_interface_extruder");
         optgroup->append_single_option_line("wipe_tower_extruder");
+        optgroup->append_single_option_line("bed_temperature_extruder");
 
         optgroup = page->new_optgroup(L("Ooze prevention"));
         optgroup->append_single_option_line("ooze_prevention");