PrusaSlicer/src/libslic3r/GCode/AvoidCrossingPerimeters.cpp

591 lines
28 KiB
C++

#include "../Layer.hpp"
#include "../MotionPlanner.hpp"
#include "../GCode.hpp"
#include "../MotionPlanner.hpp"
#include "../EdgeGrid.hpp"
#include "../Geometry.hpp"
#include "../ShortestPath.hpp"
#include "../Print.hpp"
#include "../Polygon.hpp"
#include "../ExPolygon.hpp"
#include "../ClipperUtils.hpp"
#include "AvoidCrossingPerimeters.hpp"
#include <memory>
namespace Slic3r {
void AvoidCrossingPerimeters::init_external_mp(const Print& print)
{
m_external_mp = Slic3r::make_unique<MotionPlanner>(union_ex(this->collect_contours_all_layers(print.objects())));
}
// Plan a travel move while minimizing the number of perimeter crossings.
// point is in unscaled coordinates, in the coordinate system of the current active object
// (set by gcodegen.set_origin()).
Polyline AvoidCrossingPerimeters::travel_to(const GCode& gcodegen, const Point& point)
{
// If use_external, then perform the path planning in the world coordinate system (correcting for the gcodegen offset).
// Otherwise perform the path planning in the coordinate system of the active object.
bool use_external = this->use_external_mp || this->use_external_mp_once;
Point scaled_origin = use_external ? Point::new_scale(gcodegen.origin()(0), gcodegen.origin()(1)) : Point(0, 0);
Polyline result = (use_external ? m_external_mp.get() : m_layer_mp.get())->
shortest_path(gcodegen.last_pos() + scaled_origin, point + scaled_origin);
if (use_external)
result.translate(-scaled_origin);
return result;
}
// Collect outer contours of all objects over all layers.
// Discard objects only containing thin walls (offset would fail on an empty polygon).
// Used by avoid crossing perimeters feature.
Polygons AvoidCrossingPerimeters::collect_contours_all_layers(const PrintObjectPtrs& objects)
{
Polygons islands;
for (const PrintObject* object : objects) {
// Reducing all the object slices into the Z projection in a logarithimc fashion.
// First reduce to half the number of layers.
std::vector<Polygons> polygons_per_layer((object->layers().size() + 1) / 2);
tbb::parallel_for(tbb::blocked_range<size_t>(0, object->layers().size() / 2),
[&object, &polygons_per_layer](const tbb::blocked_range<size_t>& range) {
for (size_t i = range.begin(); i < range.end(); ++i) {
const Layer* layer1 = object->layers()[i * 2];
const Layer* layer2 = object->layers()[i * 2 + 1];
Polygons polys;
polys.reserve(layer1->lslices.size() + layer2->lslices.size());
for (const ExPolygon& expoly : layer1->lslices)
//FIXME no holes?
polys.emplace_back(expoly.contour);
for (const ExPolygon& expoly : layer2->lslices)
//FIXME no holes?
polys.emplace_back(expoly.contour);
polygons_per_layer[i] = union_(polys);
}
});
if (object->layers().size() & 1) {
const Layer* layer = object->layers().back();
Polygons polys;
polys.reserve(layer->lslices.size());
for (const ExPolygon& expoly : layer->lslices)
//FIXME no holes?
polys.emplace_back(expoly.contour);
polygons_per_layer.back() = union_(polys);
}
// Now reduce down to a single layer.
size_t cnt = polygons_per_layer.size();
while (cnt > 1) {
tbb::parallel_for(tbb::blocked_range<size_t>(0, cnt / 2),
[&polygons_per_layer](const tbb::blocked_range<size_t>& range) {
for (size_t i = range.begin(); i < range.end(); ++i) {
Polygons polys;
polys.reserve(polygons_per_layer[i * 2].size() + polygons_per_layer[i * 2 + 1].size());
polygons_append(polys, polygons_per_layer[i * 2]);
polygons_append(polys, polygons_per_layer[i * 2 + 1]);
polygons_per_layer[i * 2] = union_(polys);
}
});
for (size_t i = 1; i < cnt / 2; ++i)
polygons_per_layer[i] = std::move(polygons_per_layer[i * 2]);
if (cnt & 1)
polygons_per_layer[cnt / 2] = std::move(polygons_per_layer[cnt - 1]);
cnt = (cnt + 1) / 2;
}
// And collect copies of the objects.
for (const PrintInstance& instance : object->instances()) {
// All the layers were reduced to the 1st item of polygons_per_layer.
size_t i = islands.size();
polygons_append(islands, polygons_per_layer.front());
for (; i < islands.size(); ++i)
islands[i].translate(instance.shift);
}
}
return islands;
}
// Create a rotation matrix for projection on the given vector
static Matrix2d rotation_by_direction(const Point &direction)
{
Matrix2d rotation;
rotation.block<1, 2>(0, 0) = direction.cast<double>() / direction.cast<double>().norm();
rotation(1, 0) = -rotation(0, 1);
rotation(1, 1) = rotation(0, 0);
return rotation;
}
static Point find_first_different_vertex(const Polygon &polygon, const size_t point_idx, const Point &point, bool forward)
{
if (point != polygon.points[point_idx])
return polygon.points[point_idx];
int line_idx = point_idx;
if (forward)
for (; point == polygon.points[line_idx]; line_idx = (((line_idx + 1) < int(polygon.points.size())) ? (line_idx + 1) : 0));
else
for (; point == polygon.points[line_idx]; line_idx = (((line_idx - 1) >= 0) ? (line_idx - 1) : (int(polygon.points.size()) - 1)));
return polygon.points[line_idx];
}
static Vec2d three_points_inward_normal(const Point &left, const Point &middle, const Point &right)
{
assert(left != middle);
assert(middle != right);
Vec2d normal_1(-1 * (middle.y() - left.y()), middle.x() - left.x());
Vec2d normal_2(-1 * (right.y() - middle.y()), right.x() - middle.x());
normal_1.normalize();
normal_2.normalize();
return (normal_1 + normal_2).normalized();
};
static Vec2d get_polygon_vertex_inward_normal(const Polygon &polygon, const size_t point_idx)
{
const size_t left_idx = (point_idx <= 0) ? (polygon.size() - 1) : (point_idx - 1);
const size_t right_idx = (point_idx >= (polygon.size() - 1)) ? 0 : (point_idx + 1);
const Point &middle = polygon.points[point_idx];
const Point &left = find_first_different_vertex(polygon, left_idx, middle, false);
const Point &right = find_first_different_vertex(polygon, right_idx, middle, true);
return three_points_inward_normal(left, middle, right);
}
// Compute offset of polygon's in a direction inward normal
static Point get_polygon_vertex_offset(const Polygon &polygon, const size_t point_idx, const int offset)
{
return polygon.points[point_idx] + (get_polygon_vertex_inward_normal(polygon, point_idx) * double(offset)).cast<coord_t>();
}
static Point get_middle_point_offset(const Polygon &polygon, const size_t left_idx, const size_t right_idx, const Point &middle, const int offset)
{
const Point &left = find_first_different_vertex(polygon, left_idx, middle, false);
const Point &right = find_first_different_vertex(polygon, right_idx, middle, true);
return middle + (three_points_inward_normal(left, middle, right) * double(offset)).cast<coord_t>();
}
static bool check_if_could_cross_perimeters(const BoundingBox &bbox, const Point &start, const Point &end)
{
bool start_out_of_bound = !bbox.contains(start), end_out_of_bound = !bbox.contains(end);
// When both endpoints are out of the bounding box, it needs to check in more detail.
if (start_out_of_bound && end_out_of_bound) {
Point intersection;
return bbox.polygon().intersection(Line(start, end), &intersection);
}
return true;
}
static std::pair<Point, Point> clamp_endpoints_by_bounding_box(const BoundingBox &bbox, const Point &start, const Point &end)
{
bool start_out_of_bound = !bbox.contains(start), end_out_of_bound = !bbox.contains(end);
Point start_clamped = start, end_clamped = end;
Points intersections;
if (start_out_of_bound || end_out_of_bound) {
bbox.polygon().intersections(Line(start, end), &intersections);
assert(intersections.size() <= 2);
}
if (start_out_of_bound && !end_out_of_bound && intersections.size() == 1) {
start_clamped = intersections[0];
} else if (!start_out_of_bound && end_out_of_bound && intersections.size() == 1) {
end_clamped = intersections[0];
} else if (start_out_of_bound && end_out_of_bound && intersections.size() == 2) {
if ((intersections[0] - start).cast<double>().norm() < (intersections[1] - start).cast<double>().norm()) {
start_clamped = intersections[0];
end_clamped = intersections[1];
} else {
start_clamped = intersections[1];
end_clamped = intersections[0];
}
}
return std::make_pair(start_clamped, end_clamped);
}
static inline coord_t get_default_perimeter_spacing(const Print &print)
{
const std::vector<double> &nozzle_diameters = print.config().nozzle_diameter.values;
return scale_(*std::max_element(nozzle_diameters.begin(), nozzle_diameters.end()));
}
static coord_t get_perimeter_spacing(const Layer &layer)
{
size_t regions_count = 0;
coord_t perimeter_spacing = 0;
for (const LayerRegion *layer_region : layer.regions()) {
perimeter_spacing += layer_region->flow(frPerimeter).scaled_spacing();
++regions_count;
}
assert(perimeter_spacing >= 0);
if (regions_count != 0)
perimeter_spacing /= regions_count;
else
perimeter_spacing = get_default_perimeter_spacing(*layer.object()->print());
return perimeter_spacing;
}
static coord_t get_perimeter_spacing_external(const Layer &layer)
{
size_t regions_count = 0;
coord_t perimeter_spacing = 0;
for (const PrintObject *object : layer.object()->print()->objects())
for (Layer *l : object->layers())
if ((layer.print_z - EPSILON) <= l->print_z && l->print_z <= (layer.print_z + EPSILON))
for (const LayerRegion *layer_region : l->regions()) {
perimeter_spacing += layer_region->flow(frPerimeter).scaled_spacing();
++regions_count;
}
assert(perimeter_spacing >= 0);
if (regions_count != 0)
perimeter_spacing /= regions_count;
else
perimeter_spacing = get_default_perimeter_spacing(*layer.object()->print());
return perimeter_spacing;
}
ExPolygons AvoidCrossingPerimeters2::get_boundary(const Layer &layer)
{
const coord_t perimeter_spacing = get_perimeter_spacing(layer);
const coord_t offset = perimeter_spacing / 2;
size_t polygons_count = 0;
for (const LayerRegion *layer_region : layer.regions())
polygons_count += layer_region->slices.surfaces.size();
ExPolygons boundary;
boundary.reserve(polygons_count);
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->slices.surfaces) boundary.emplace_back(surface.expolygon);
boundary = union_ex(boundary);
ExPolygons perimeter_boundary = offset_ex(boundary, -offset);
ExPolygons final_boundary;
if (perimeter_boundary.size() != boundary.size()) {
// If any part of the polygon is missing after shrinking, the boundary of slice is used instead.
ExPolygons missing_perimeter_boundary = offset_ex(diff_ex(boundary, offset_ex(perimeter_boundary, offset + SCALED_EPSILON / 2)),
offset + SCALED_EPSILON);
perimeter_boundary = offset_ex(perimeter_boundary, offset);
perimeter_boundary.reserve(perimeter_boundary.size() + missing_perimeter_boundary.size());
perimeter_boundary.insert(perimeter_boundary.begin(), missing_perimeter_boundary.begin(), missing_perimeter_boundary.end());
final_boundary = union_ex(intersection_ex(offset_ex(perimeter_boundary, -offset), boundary));
} else {
final_boundary = std::move(perimeter_boundary);
}
// Add an outer boundary to avoid crossing perimeters from supports
ExPolygons outer_boundary = diff_ex(offset_ex(boundary, 2 * perimeter_spacing), offset_ex(boundary, 2 * perimeter_spacing - offset));
final_boundary.reserve(final_boundary.size() + outer_boundary.size());
final_boundary.insert(final_boundary.begin(), outer_boundary.begin(), outer_boundary.end());
final_boundary = union_ex(final_boundary);
// Collect all top layers that will not be crossed.
polygons_count = 0;
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) ++polygons_count;
if (polygons_count > 0) {
ExPolygons top_layer_polygons;
top_layer_polygons.reserve(polygons_count);
for (const LayerRegion *layer_region : layer.regions())
for (const Surface &surface : layer_region->fill_surfaces.surfaces)
if (surface.is_top()) top_layer_polygons.emplace_back(surface.expolygon);
top_layer_polygons = union_ex(top_layer_polygons);
return diff_ex(final_boundary, offset_ex(top_layer_polygons, -offset));
}
return final_boundary;
}
ExPolygons AvoidCrossingPerimeters2::get_boundary_external(const Layer &layer)
{
ExPolygons boundary;
for (const PrintObject *object : layer.object()->print()->objects()) {
ExPolygons polygons_per_obj;
for (Layer *l : object->layers())
if ((layer.print_z - EPSILON) <= l->print_z && l->print_z <= (layer.print_z + EPSILON))
for (const LayerRegion *layer_region : l->regions())
for (const Surface &surface : layer_region->slices.surfaces)
polygons_per_obj.emplace_back(surface.expolygon);
for (const PrintInstance &instance : object->instances()) {
size_t boundary_idx = boundary.size();
boundary.reserve(boundary.size() + polygons_per_obj.size());
boundary.insert(boundary.end(), polygons_per_obj.begin(), polygons_per_obj.end());
for (; boundary_idx < boundary.size(); ++boundary_idx) boundary[boundary_idx].translate(instance.shift.x(), instance.shift.y());
}
}
const coord_t perimeter_spacing = get_perimeter_spacing_external(layer);
const coord_t perimeter_offset = perimeter_spacing / 2;
Polygons contours;
Polygons holes;
for (ExPolygon &poly : boundary) {
contours.emplace_back(poly.contour);
append(holes, poly.holes);
}
ExPolygons final_boundary = union_ex(diff(offset(contours, perimeter_spacing * 3), offset(contours, 3 * perimeter_spacing - perimeter_offset)));
ExPolygons holes_boundary = union_ex(diff(offset(holes, perimeter_spacing), offset(holes, perimeter_offset)));
final_boundary.reserve(final_boundary.size() + holes_boundary.size());
final_boundary.insert(final_boundary.end(), holes_boundary.begin(), holes_boundary.end());
final_boundary = union_ex(final_boundary);
return final_boundary;
}
// Returns a direction of the shortest path along the polygon boundary
AvoidCrossingPerimeters2::Direction AvoidCrossingPerimeters2::get_shortest_direction(const Lines &lines,
const size_t start_idx,
const size_t end_idx,
const Point &intersection_first,
const Point &intersection_last)
{
double total_length_forward = (lines[start_idx].b - intersection_first).cast<double>().norm();
double total_length_backward = (lines[start_idx].a - intersection_first).cast<double>().norm();
auto cyclic_index = [&lines](int index) {
if (index >= int(lines.size()))
index = 0;
else if (index < 0)
index = lines.size() - 1;
return index;
};
for (int line_idx = cyclic_index(int(start_idx) + 1); line_idx != int(end_idx); line_idx = cyclic_index(line_idx + 1))
total_length_forward += lines[line_idx].length();
for (int line_idx = cyclic_index(int(start_idx) - 1); line_idx != int(end_idx); line_idx = cyclic_index(line_idx - 1))
total_length_backward += lines[line_idx].length();
total_length_forward += (lines[end_idx].a - intersection_last).cast<double>().norm();
total_length_backward += (lines[end_idx].b - intersection_last).cast<double>().norm();
return (total_length_forward < total_length_backward) ? Direction::Forward : Direction::Backward;
}
Polyline AvoidCrossingPerimeters2::simplify_travel(const EdgeGrid::Grid &edge_grid, const Polyline &travel)
{
struct Visitor
{
Visitor(const EdgeGrid::Grid &grid) : grid(grid) {}
bool operator()(coord_t iy, coord_t ix)
{
assert(pt_current != nullptr);
assert(pt_next != nullptr);
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
this->intersect = false;
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second; ++it_contour_and_segment) {
// End points of the line segment and their vector.
auto segment = grid.segment(*it_contour_and_segment);
if (Geometry::segments_intersect(segment.first, segment.second, *pt_current, *pt_next)) {
this->intersect = true;
return false;
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
const Slic3r::Point *pt_current = nullptr;
const Slic3r::Point *pt_next = nullptr;
bool intersect = false;
} visitor(edge_grid);
Polyline optimized_comb_path;
optimized_comb_path.points.reserve(travel.points.size());
optimized_comb_path.points.emplace_back(travel.points.front());
// Try to skip some points in the path.
for (size_t point_idx = 1; point_idx < travel.size(); point_idx++) {
const Point &current_point = travel.points[point_idx - 1];
Point next = travel.points[point_idx];
visitor.pt_current = &current_point;
for (size_t point_idx_2 = point_idx + 1; point_idx_2 < travel.size(); point_idx_2++) {
if (travel.points[point_idx_2] == current_point) {
next = travel.points[point_idx_2];
point_idx = point_idx_2;
continue;
}
visitor.pt_next = &travel.points[point_idx_2];
edge_grid.visit_cells_intersecting_line(*visitor.pt_current, *visitor.pt_next, visitor);
// Check if deleting point causes crossing a boundary
if (!visitor.intersect) {
next = travel.points[point_idx_2];
point_idx = point_idx_2;
}
}
optimized_comb_path.append(next);
}
return optimized_comb_path;
}
Polyline AvoidCrossingPerimeters2::avoid_perimeters(const Polygons &boundaries,
const EdgeGrid::Grid &edge_grid,
const Point &start,
const Point &end)
{
const Point direction = end - start;
Matrix2d transform_to_x_axis = rotation_by_direction(direction);
const Line travel_line_orig(start, end);
const Line travel_line((transform_to_x_axis * start.cast<double>()).cast<coord_t>(),
(transform_to_x_axis * end.cast<double>()).cast<coord_t>());
std::vector<Intersection> intersections;
{
struct Visitor
{
Visitor(const EdgeGrid::Grid & grid,
std::vector<Intersection> &intersections,
const Matrix2d & transform_to_x_axis,
const Line & travel_line)
: grid(grid), intersections(intersections), transform_to_x_axis(transform_to_x_axis), travel_line(travel_line)
{}
bool operator()(coord_t iy, coord_t ix)
{
// Called with a row and colum of the grid cell, which is intersected by a line.
auto cell_data_range = grid.cell_data_range(iy, ix);
for (auto it_contour_and_segment = cell_data_range.first; it_contour_and_segment != cell_data_range.second;
++it_contour_and_segment) {
// End points of the line segment and their vector.
auto segment = grid.segment(*it_contour_and_segment);
Point intersection_point;
if (travel_line.intersection(Line(segment.first, segment.second), &intersection_point) &&
intersection_set.find(*it_contour_and_segment) == intersection_set.end()) {
intersections.emplace_back(it_contour_and_segment->first, it_contour_and_segment->second,
(transform_to_x_axis * intersection_point.cast<double>()).cast<coord_t>(), intersection_point);
intersection_set.insert(*it_contour_and_segment);
}
}
// Continue traversing the grid along the edge.
return true;
}
const EdgeGrid::Grid &grid;
std::vector<Intersection> &intersections;
const Matrix2d &transform_to_x_axis;
const Line &travel_line;
std::unordered_set<std::pair<size_t, size_t>, boost::hash<std::pair<size_t, size_t>>> intersection_set;
} visitor(edge_grid, intersections, transform_to_x_axis, travel_line_orig);
edge_grid.visit_cells_intersecting_line(start, end, visitor);
}
std::sort(intersections.begin(), intersections.end());
Polyline result;
result.append(start);
for (auto it_first = intersections.begin(); it_first != intersections.end(); ++it_first) {
const Intersection &intersection_first = *it_first;
for (auto it_second = it_first + 1; it_second != intersections.end(); ++it_second) {
const Intersection &intersection_second = *it_second;
if (intersection_first.border_idx == intersection_second.border_idx) {
Lines border_lines = boundaries[intersection_first.border_idx].lines();
// Append the nearest intersection into the path
size_t left_idx = intersection_first.line_idx;
size_t right_idx = (intersection_first.line_idx >= (boundaries[intersection_first.border_idx].points.size() - 1)) ? 0 : (intersection_first.line_idx + 1);
result.append(get_middle_point_offset(boundaries[intersection_first.border_idx], left_idx, right_idx, intersection_first.point, SCALED_EPSILON));
Direction shortest_direction = get_shortest_direction(border_lines, intersection_first.line_idx, intersection_second.line_idx,
intersection_first.point, intersection_second.point);
// Append the path around the border into the path
// Offset of the polygon's point is used to simplify calculation of intersection between boundary
if (shortest_direction == Direction::Forward)
for (int line_idx = intersection_first.line_idx; line_idx != int(intersection_second.line_idx);
line_idx = (((line_idx + 1) < int(border_lines.size())) ? (line_idx + 1) : 0))
result.append(get_polygon_vertex_offset(boundaries[intersection_first.border_idx],
(line_idx + 1 == int(boundaries[intersection_first.border_idx].points.size())) ? 0 : (line_idx + 1), SCALED_EPSILON));
else
for (int line_idx = intersection_first.line_idx; line_idx != int(intersection_second.line_idx);
line_idx = (((line_idx - 1) >= 0) ? (line_idx - 1) : (int(border_lines.size()) - 1)))
result.append(get_polygon_vertex_offset(boundaries[intersection_second.border_idx], line_idx + 0, SCALED_EPSILON));
// Append the farthest intersection into the path
left_idx = intersection_second.line_idx;
right_idx = (intersection_second.line_idx >= (boundaries[intersection_second.border_idx].points.size() - 1)) ? 0 : (intersection_second.line_idx + 1);
result.append(get_middle_point_offset(boundaries[intersection_second.border_idx], left_idx, right_idx, intersection_second.point, SCALED_EPSILON));
// Skip intersections in between
it_first = (it_second - 1);
break;
}
}
}
result.append(end);
return simplify_travel(edge_grid, result);
}
Polyline AvoidCrossingPerimeters2::travel_to(const GCode &gcodegen, const Point &point)
{
// If use_external, then perform the path planning in the world coordinate system (correcting for the gcodegen offset).
// Otherwise perform the path planning in the coordinate system of the active object.
bool use_external = this->use_external_mp || this->use_external_mp_once;
Point scaled_origin = use_external ? Point::new_scale(gcodegen.origin()(0), gcodegen.origin()(1)) : Point(0, 0);
Point start = gcodegen.last_pos() + scaled_origin;
Point end = point + scaled_origin;
Polyline result;
if (!check_if_could_cross_perimeters(use_external ? m_bbox_external : m_bbox, start, end)) {
result = Polyline({start, end});
} else {
auto [start_clamped, end_clamped] = clamp_endpoints_by_bounding_box(use_external ? m_bbox_external : m_bbox, start, end);
if (use_external)
result = this->avoid_perimeters(m_boundaries_external, m_grid_external, start_clamped, end_clamped);
else
result = this->avoid_perimeters(m_boundaries, m_grid, start_clamped, end_clamped);
}
result.points.front() = start;
result.points.back() = end;
Line travel(start, end);
double max_detour_length scale_(gcodegen.config().avoid_crossing_perimeters_max_detour);
if ((max_detour_length > 0) && ((result.length() - travel.length()) > max_detour_length)) {
result = Polyline({start, end});
}
if (use_external)
result.translate(-scaled_origin);
return result;
}
void AvoidCrossingPerimeters2::init_layer(const Layer &layer)
{
m_boundaries.clear();
m_boundaries_external.clear();
ExPolygons boundaries = get_boundary(layer);
ExPolygons boundaries_external = get_boundary_external(layer);
m_bbox = get_extents(boundaries);
m_bbox.offset(SCALED_EPSILON);
m_bbox_external = get_extents(boundaries_external);
m_bbox_external.offset(SCALED_EPSILON);
for (const ExPolygon &ex_poly : boundaries) {
m_boundaries.emplace_back(ex_poly.contour);
append(m_boundaries, ex_poly.holes);
}
for (const ExPolygon &ex_poly : boundaries_external) {
m_boundaries_external.emplace_back(ex_poly.contour);
append(m_boundaries_external, ex_poly.holes);
}
m_grid.set_bbox(m_bbox);
m_grid.create(m_boundaries, scale_(1.));
m_grid_external.set_bbox(m_bbox_external);
m_grid_external.create(m_boundaries_external, scale_(1.));
}
} // namespace Slic3r