Add minimum external perimeter fan speed to Dynamic fan speed

src/libslic3r/GCode.cpp

@@ -3038,6 +3038,7 @@ std::string GCode::_extrude(const ExtrusionPath &path, const std::string_view de
 
  new_points = m_extrusion_quality_estimator.estimate_speed_from_extrusion_quality(path, overhangs_with_speeds, overhang_w_fan_speeds,
  m_writer.extruder()->id(), external_perim_reference_speed,
+ m_config.external_perimeter_fan_speed.get_at(m_writer.extruder()->id()),
  speed);
  variable_speed_or_fan_speed = std::any_of(new_points.begin(), new_points.end(),
  [speed](const ProcessedPoint &p) { return p.speed != speed || p.fan_speed != 0; });

src/libslic3r/GCode/CoolingBuffer.cpp

@@ -753,7 +753,10 @@ std::string CoolingBuffer::apply_layer_cooldown(
 #define EXTRUDER_CONFIG(OPT) m_config.OPT.get_at(m_current_extruder)
  int min_fan_speed = EXTRUDER_CONFIG(min_fan_speed);
  int fan_speed_new = EXTRUDER_CONFIG(fan_always_on) ? min_fan_speed : 0;
- std::pair<int, int> custom_fan_speed_limits{fan_speed_new, 100 };
+ struct {
+ int min;
+ float factor;
+ } custom_fan_speed_limits{fan_speed_new, 1.0};
  int disable_fan_first_layers = EXTRUDER_CONFIG(disable_fan_first_layers);
  // Is the fan speed ramp enabled?
  int full_fan_speed_layer = EXTRUDER_CONFIG(full_fan_speed_layer);
@@ -770,42 +773,41 @@ std::string CoolingBuffer::apply_layer_cooldown(
  if (layer_time < slowdown_below_layer_time) {
  // Layer time very short. Enable the fan to a full throttle.
  fan_speed_new = max_fan_speed;
- custom_fan_speed_limits.first = fan_speed_new;
+ custom_fan_speed_limits.min = fan_speed_new;
  } else if (layer_time < fan_below_layer_time) {
  // Layer time quite short. Enable the fan proportionally according to the current layer time.
  assert(layer_time >= slowdown_below_layer_time);
  double t = (layer_time - slowdown_below_layer_time) / (fan_below_layer_time - slowdown_below_layer_time);
  fan_speed_new = int(floor(t * min_fan_speed + (1. - t) * max_fan_speed) + 0.5);
- custom_fan_speed_limits.first = fan_speed_new;
+ custom_fan_speed_limits.min = fan_speed_new;
  }
  }
  bridge_fan_speed = EXTRUDER_CONFIG(bridge_fan_speed);
- if (int(layer_id) >= disable_fan_first_layers && int(layer_id) + 1 < full_fan_speed_layer) {
+ if (int(layer_id) + 1 < full_fan_speed_layer) {
  // Ramp up the fan speed from disable_fan_first_layers to full_fan_speed_layer.
  float factor = float(int(layer_id + 1) - disable_fan_first_layers) / float(full_fan_speed_layer - disable_fan_first_layers);
  fan_speed_new = std::clamp(int(float(fan_speed_new) * factor + 0.5f), 0, 255);
  bridge_fan_speed = std::clamp(int(float(bridge_fan_speed) * factor + 0.5f), 0, 255);
- custom_fan_speed_limits.second = fan_speed_new;
+ custom_fan_speed_limits = {fan_speed_new, factor};
  }
 #undef EXTRUDER_CONFIG
  bridge_fan_control = bridge_fan_speed > fan_speed_new;
  } else { // fan disabled
  bridge_fan_control = false;
  bridge_fan_speed = 0;
  fan_speed_new = 0;
- custom_fan_speed_limits.second = 0;
+ custom_fan_speed_limits = {0, 0.0};
  }
  if (fan_speed_new != m_fan_speed) {
  m_fan_speed = fan_speed_new;
  new_gcode += GCodeWriter::set_fan(m_config.gcode_flavor, m_config.gcode_comments, m_fan_speed);
  }
- custom_fan_speed_limits.first = std::min(custom_fan_speed_limits.first, custom_fan_speed_limits.second);
  return custom_fan_speed_limits;
  };
 
  const char *pos = gcode.c_str();
  int current_feedrate = 0;
- std::pair<int,int> fan_speed_limits = change_extruder_set_fan();
+ auto fan_speed_limits = change_extruder_set_fan();
  for (const CoolingLine *line : lines) {
  const char *line_start = gcode.c_str() + line->line_start;
  const char *line_end = gcode.c_str() + line->line_end;
@@ -820,7 +822,7 @@ std::string CoolingBuffer::apply_layer_cooldown(
  }
  new_gcode.append(line_start, line_end - line_start);
  } else if (line->type & CoolingLine::TYPE_SET_FAN_SPEED) {
- int new_speed = std::clamp(line->fan_speed, fan_speed_limits.first, fan_speed_limits.second);
+ int new_speed = std::max(int(line->fan_speed * fan_speed_limits.factor + 0.5), fan_speed_limits.min);
  if (m_fan_speed != new_speed) {
  new_gcode += GCodeWriter::set_fan(m_config.gcode_flavor, m_config.gcode_comments, new_speed);
  m_fan_speed = new_speed;

src/libslic3r/GCode/ExtrusionProcessor.hpp

@@ -246,6 +246,7 @@ class ExtrusionQualityEstimator
  const std::vector<std::pair<int, ConfigOptionInts>> overhangs_w_fan_speeds,
  size_t extruder_id,
  float ext_perimeter_speed,
+ float external_perimeter_fan_speed,
  float original_speed)
  {
  float speed_base = ext_perimeter_speed > 0 ? ext_perimeter_speed : original_speed;
@@ -310,6 +311,8 @@ class ExtrusionQualityEstimator
  float final_speed = std::min(curled_base_speed, extrusion_speed);
  float fan_speed = std::min(interpolate_speed(fan_speed_sections, curr.distance),
  interpolate_speed(fan_speed_sections, next.distance));
+ if (path.role().is_external_perimeter() && external_perimeter_fan_speed > fan_speed)
+ fan_speed = external_perimeter_fan_speed;
 
  processed_points.push_back({scaled(curr.position), final_speed, int(fan_speed)});
  }

src/libslic3r/Preset.cpp

@@ -469,7 +469,7 @@ static std::vector<std::string> s_Preset_filament_options {
  "temperature", "idle_temperature", "first_layer_temperature", "bed_temperature", "first_layer_bed_temperature", "fan_always_on", "cooling", "min_fan_speed",
  "max_fan_speed", "bridge_fan_speed", "disable_fan_first_layers", "full_fan_speed_layer", "fan_below_layer_time", "slowdown_below_layer_time", "min_print_speed",
  "start_filament_gcode", "end_filament_gcode", "enable_dynamic_fan_speeds",
- "overhang_fan_speed_0", "overhang_fan_speed_1", "overhang_fan_speed_2", "overhang_fan_speed_3",
+ "overhang_fan_speed_0", "overhang_fan_speed_1", "overhang_fan_speed_2", "overhang_fan_speed_3", "external_perimeter_fan_speed",
  // Retract overrides
  "filament_retract_length", "filament_retract_lift", "filament_retract_lift_above", "filament_retract_lift_below", "filament_retract_speed", "filament_deretract_speed", "filament_retract_restart_extra", "filament_retract_before_travel",
  "filament_retract_layer_change", "filament_wipe", "filament_retract_before_wipe",

src/libslic3r/Print.cpp

@@ -71,6 +71,7 @@ bool Print::invalidate_state_by_config_options(const ConfigOptionResolver & /* n
  "overhang_fan_speed_1",
  "overhang_fan_speed_2",
  "overhang_fan_speed_3",
+ "external_perimeter_fan_speed",
  "colorprint_heights",
  "cooling",
  "default_acceleration",

src/libslic3r/PrintConfig.cpp

@@ -624,6 +624,15 @@ void PrintConfigDef::init_fff_params()
  def->mode = comExpert;
  def->set_default_value(new ConfigOptionInts{0});
 
+ def = this->add("external_perimeter_fan_speed", coInts);
+ def->label = L("minimum speed for external perimeters");
+ def->tooltip = fan_speed_setting_description;
+ def->sidetext = L("%");
+ def->min = 0;
+ def->max = 100;
+ def->mode = comExpert;
+ def->set_default_value(new ConfigOptionInts{0});
+
  def = this->add("brim_width", coFloat);
  def->label = L("Brim width");
  def->category = L("Skirt and brim");

src/libslic3r/PrintConfig.hpp

@@ -759,6 +759,7 @@ PRINT_CONFIG_CLASS_DERIVED_DEFINE(
  ((ConfigOptionInts, overhang_fan_speed_1))
  ((ConfigOptionInts, overhang_fan_speed_2))
  ((ConfigOptionInts, overhang_fan_speed_3))
+ ((ConfigOptionInts, external_perimeter_fan_speed))
  ((ConfigOptionBool, complete_objects))
  ((ConfigOptionFloats, colorprint_heights))
  ((ConfigOptionBools, cooling))

src/slic3r/GUI/Tab.cpp

@@ -2060,6 +2060,7 @@ void TabFilament::build()
  optgroup->append_single_option_line("overhang_fan_speed_1", category_path + "dynamic-fan-speeds");
  optgroup->append_single_option_line("overhang_fan_speed_2", category_path + "dynamic-fan-speeds");
  optgroup->append_single_option_line("overhang_fan_speed_3", category_path + "dynamic-fan-speeds");
+ optgroup->append_single_option_line("external_perimeter_fan_speed", category_path + "dynamic-fan-speeds");
 
  optgroup = page->new_optgroup(L("Cooling thresholds"), 25);
  optgroup->append_single_option_line("fan_below_layer_time", category_path + "cooling-thresholds");
@@ -2218,6 +2219,7 @@ void TabFilament::toggle_options()
  for (int i = 0; i < 4; i++) {
  toggle_option("overhang_fan_speed_"+std::to_string(i),dynamic_fan_speeds);
  }
+ toggle_option("external_perimeter_fan_speed", dynamic_fan_speeds);
  }
 
  if (m_active_page->title() == "Filament Overrides")