OrcaSlicer/lib/Slic3r/Print/Object.pm

package Slic3r::Print::Object;
use Moo;

use Slic3r::ExtrusionPath ':roles';
use Slic3r::Geometry qw(scale unscale deg2rad);
use Slic3r::Geometry::Clipper qw(diff_ex intersection_ex union_ex);
use Slic3r::Surface ':types';

has 'input_file'        => (is => 'rw', required => 0);
has 'mesh'              => (is => 'rw', required => 0);
has 'size'              => (is => 'rw', required => 1);

has 'layers' => (
    traits  => ['Array'],
    is      => 'rw',
    #isa     => 'ArrayRef[Slic3r::Layer]',
    default => sub { [] },
);

sub layer_count {
    my $self = shift;
    return scalar @{ $self->layers };
}

sub layer {
    my $self = shift;
    my ($layer_id) = @_;
    
    # extend our print by creating all necessary layers
    
    if ($self->layer_count < $layer_id + 1) {
        for (my $i = $self->layer_count; $i <= $layer_id; $i++) {
            push @{ $self->layers }, Slic3r::Layer->new(id => $i);
        }
    }
    
    return $self->layers->[$layer_id];
}

sub slice {
    my $self = shift;
    my %params = @_;
    
    # process facets
    {
        my $apply_lines = sub {
            my $lines = shift;
            foreach my $layer_id (keys %$lines) {
                my $layer = $self->layer($layer_id);
                push @{$layer->lines}, @{$lines->{$layer_id}};
            }
        };
        Slic3r::parallelize(
            disable => ($#{$self->mesh->facets} < 500),  # don't parallelize when too few facets
            items => [ 0..$#{$self->mesh->facets} ],
            thread_cb => sub {
                my $q = shift;
                my $result_lines = {};
                while (defined (my $facet_id = $q->dequeue)) {
                    my $lines = $self->mesh->slice_facet($self, $facet_id);
                    foreach my $layer_id (keys %$lines) {
                        $result_lines->{$layer_id} ||= [];
                        push @{ $result_lines->{$layer_id} }, @{ $lines->{$layer_id} };
                    }
                }
                return $result_lines;
            },
            collect_cb => sub {
                $apply_lines->($_[0]);
            },
            no_threads_cb => sub {
                for (0..$#{$self->mesh->facets}) {
                    my $lines = $self->mesh->slice_facet($self, $_);
                    $apply_lines->($lines);
                }
            },
        );
    }
    die "Invalid input file\n" if !@{$self->layers};
    
    # free memory
    $self->mesh(undef) unless $params{keep_meshes};
    
    # remove last layer if empty
    # (we might have created it because of the $max_layer = ... + 1 code below)
    pop @{$self->layers} if !@{$self->layers->[-1]->lines};
    
    foreach my $layer (@{ $self->layers }) {
        Slic3r::debugf "Making surfaces for layer %d (slice z = %f):\n",
            $layer->id, unscale $layer->slice_z if $Slic3r::debug;
        
        # layer currently has many lines representing intersections of
        # model facets with the layer plane. there may also be lines
        # that we need to ignore (for example, when two non-horizontal
        # facets share a common edge on our plane, we get a single line;
        # however that line has no meaning for our layer as it's enclosed
        # inside a closed polyline)
        
        # build surfaces from sparse lines
        $layer->make_surfaces(Slic3r::TriangleMesh::make_loops($layer));
        
        # free memory
        $layer->lines(undef);
    }
    
    # detect slicing errors
    my $warning_thrown = 0;
    for my $i (0 .. $#{$self->layers}) {
        my $layer = $self->layers->[$i];
        next unless $layer->slicing_errors;
        if (!$warning_thrown) {
            warn "The model has overlapping or self-intersecting facets. I tried to repair it, "
                . "however you might want to check the results or repair the input file and retry.\n";
            $warning_thrown = 1;
        }
        
        # try to repair the layer surfaces by merging all contours and all holes from
        # neighbor layers
        Slic3r::debugf "Attempting to repair layer %d\n", $i;
        
        my (@upper_surfaces, @lower_surfaces);
        for (my $j = $i+1; $j <= $#{$self->layers}; $j++) {
            if (!$self->layers->[$j]->slicing_errors) {
                @upper_surfaces = @{$self->layers->[$j]->slices};
                last;
            }
        }
        for (my $j = $i-1; $j >= 0; $j--) {
            if (!$self->layers->[$j]->slicing_errors) {
                @lower_surfaces = @{$self->layers->[$j]->slices};
                last;
            }
        }
        
        my $union = union_ex([
            map $_->expolygon->contour, @upper_surfaces, @lower_surfaces,
        ]);
        my $diff = diff_ex(
            [ map @$_, @$union ],
            [ map $_->expolygon->holes, @upper_surfaces, @lower_surfaces, ],
        );
        
        @{$layer->slices} = map Slic3r::Surface->new
            (expolygon => $_, surface_type => S_TYPE_INTERNAL),
            @$diff;
    }
    
    # remove empty layers from bottom
    while (@{$self->layers} && !@{$self->layers->[0]->slices} && !@{$self->layers->[0]->thin_walls}) {
        shift @{$self->layers};
        for (my $i = 0; $i <= $#{$self->layers}; $i++) {
            $self->layers->[$i]->id($i);
        }
    }
    
    warn "No layers were detected. You might want to repair your STL file and retry.\n"
        if !@{$self->layers};
}

sub cleanup {
    my $self = shift;
    @{$self->layers} = ();
}

sub make_perimeters {
    my $self = shift;
    
    # compare each layer to the one below, and mark those slices needing
    # one additional inner perimeter, like the top of domed objects-
    
    # this algorithm makes sure that almost one perimeter is overlapping
    if ($Slic3r::Config->extra_perimeters && $Slic3r::Config->perimeters > 0) {
        for my $layer_id (0 .. $self->layer_count-2) {
            my $layer = $self->layers->[$layer_id];
            my $upper_layer = $self->layers->[$layer_id+1];
            
            my $overlap = $layer->perimeter_flow->spacing;  # one perimeter
            
            # compute polygons representing the thickness of the first external perimeter of
            # the upper layer slices
            my $upper = diff_ex(
                [ map @$_, map $_->expolygon->offset_ex(+ 0.5 * scale $layer->perimeter_flow->spacing), @{$upper_layer->slices} ],
                [ map @$_, map $_->expolygon->offset_ex(- scale($overlap) + (0.5 * scale $layer->perimeter_flow->spacing)), @{$upper_layer->slices} ],
            );
            next if !@$upper;
            
            # we need to limit our detection to the areas which would actually benefit from 
            # more perimeters. so, let's compute the area we want to ignore
            my $ignore = [];
            {
                my $diff = diff_ex(
                    [ map @$_, map $_->expolygon->offset_ex(- ($Slic3r::Config->perimeters-0.5) * scale $layer->perimeter_flow->spacing), @{$layer->slices} ],
                    [ map @{$_->expolygon}, @{$upper_layer->slices} ],
                );
                $ignore = [ map @$_, map $_->offset_ex(scale $layer->perimeter_flow->spacing), @$diff ];
            }
            
            foreach my $slice (@{$layer->slices}) {
                my $hypothetical_perimeter_num = $Slic3r::Config->perimeters + 1;
                CYCLE: while (1) {
                    # compute polygons representing the thickness of the hypotetical new internal perimeter
                    # of our slice
                    my $hypothetical_perimeter;
                    {
                        my $outer = [ map @$_, $slice->expolygon->offset_ex(- ($hypothetical_perimeter_num-1.5) * scale $layer->perimeter_flow->spacing) ];
                        last CYCLE if !@$outer;
                        my $inner = [ map @$_, $slice->expolygon->offset_ex(- ($hypothetical_perimeter_num-0.5) * scale $layer->perimeter_flow->spacing) ];
                        last CYCLE if !@$inner;
                        $hypothetical_perimeter = diff_ex($outer, $inner);
                    }
                    last CYCLE if !@$hypothetical_perimeter;
                    
                    
                    my $intersection = intersection_ex([ map @$_, @$upper ], [ map @$_, @$hypothetical_perimeter ]);
                    $intersection = diff_ex([ map @$_, @$intersection ], $ignore) if @$ignore;
                    last CYCLE if !@{ $intersection };
                    Slic3r::debugf "  adding one more perimeter at layer %d\n", $layer_id;
                    $slice->additional_inner_perimeters(($slice->additional_inner_perimeters || 0) + 1);
                    $hypothetical_perimeter_num++;
                }
            }
        }
    }
    
    $_->make_perimeters for @{$self->layers};
}

sub detect_surfaces_type {
    my $self = shift;
    Slic3r::debugf "Detecting solid surfaces...\n";
    
    # prepare a reusable subroutine to make surface differences
    my $surface_difference = sub {
        my ($subject_surfaces, $clip_surfaces, $result_type, $layer) = @_;
        my $expolygons = diff_ex(
            [ map { ref $_ eq 'ARRAY' ? $_ : ref $_ eq 'Slic3r::ExPolygon' ? @$_ : $_->p } @$subject_surfaces ],
            [ map { ref $_ eq 'ARRAY' ? $_ : ref $_ eq 'Slic3r::ExPolygon' ? @$_ : $_->p } @$clip_surfaces ],
            1,
        );
        return grep $_->contour->is_printable($layer->flow->width),
            map Slic3r::Surface->new(expolygon => $_, surface_type => $result_type), 
            @$expolygons;
    };
    
    for (my $i = 0; $i < $self->layer_count; $i++) {
        my $layer = $self->layers->[$i];
        my $upper_layer = $self->layers->[$i+1];
        my $lower_layer = $i > 0 ? $self->layers->[$i-1] : undef;
        
        my (@bottom, @top, @internal) = ();
        
        # find top surfaces (difference between current surfaces
        # of current layer and upper one)
        if ($upper_layer) {
            @top = $surface_difference->($layer->slices, $upper_layer->slices, S_TYPE_TOP, $layer);
        } else {
            # if no upper layer, all surfaces of this one are solid
            @top = @{$layer->slices};
            $_->surface_type(S_TYPE_TOP) for @top;
        }
        
        # find bottom surfaces (difference between current surfaces
        # of current layer and lower one)
        if ($lower_layer) {
            @bottom = $surface_difference->($layer->slices, $lower_layer->slices, S_TYPE_BOTTOM, $layer);
        } else {
            # if no lower layer, all surfaces of this one are solid
            @bottom = @{$layer->slices};
            $_->surface_type(S_TYPE_BOTTOM) for @bottom;
        }
        
        # now, if the object contained a thin membrane, we could have overlapping bottom
        # and top surfaces; let's do an intersection to discover them and consider them
        # as bottom surfaces (to allow for bridge detection)
        if (@top && @bottom) {
            my $overlapping = intersection_ex([ map $_->p, @top ], [ map $_->p, @bottom ]);
            Slic3r::debugf "  layer %d contains %d membrane(s)\n", $layer->id, scalar(@$overlapping);
            @top = $surface_difference->([@top], $overlapping, S_TYPE_TOP, $layer);
        }
        
        # find internal surfaces (difference between top/bottom surfaces and others)
        @internal = $surface_difference->($layer->slices, [@top, @bottom], S_TYPE_INTERNAL, $layer);
        
        # save surfaces to layer
        @{$layer->slices} = (@bottom, @top, @internal);
        
        Slic3r::debugf "  layer %d has %d bottom, %d top and %d internal surfaces\n",
            $layer->id, scalar(@bottom), scalar(@top), scalar(@internal);
    }
    
    # clip surfaces to the fill boundaries
    foreach my $layer (@{$self->layers}) {
        my $fill_boundaries = [ map @$_, @{$layer->surfaces} ];
        @{$layer->surfaces} = ();
        foreach my $surface (@{$layer->slices}) {
            my $intersection = intersection_ex(
                [ $surface->p ],
                $fill_boundaries,
            );
            push @{$layer->surfaces}, map Slic3r::Surface->new
                (expolygon => $_, surface_type => $surface->surface_type),
                @$intersection;
        }
    }
}

sub discover_horizontal_shells {
    my $self = shift;
    
    Slic3r::debugf "==> DISCOVERING HORIZONTAL SHELLS\n";
    
    my $area_threshold = scale($Slic3r::flow->spacing) ** 2;
    
    for (my $i = 0; $i < $self->layer_count; $i++) {
        my $layer = $self->layers->[$i];
        foreach my $type (S_TYPE_TOP, S_TYPE_BOTTOM) {
            # find surfaces of current type for current layer
            # and offset them to take perimeters into account
            my @surfaces = map $_->offset($Slic3r::Config->perimeters * scale $layer->perimeter_flow->width),
                grep $_->surface_type == $type, @{$layer->fill_surfaces} or next;
            my $surfaces_p = [ map $_->p, @surfaces ];
            Slic3r::debugf "Layer %d has %d surfaces of type '%s'\n",
                $i, scalar(@surfaces), ($type == S_TYPE_TOP ? 'top' : 'bottom');
            
            for (my $n = $type == S_TYPE_TOP ? $i-1 : $i+1; 
                    abs($n - $i) <= $Slic3r::Config->solid_layers-1; 
                    $type == S_TYPE_TOP ? $n-- : $n++) {
                
                next if $n < 0 || $n >= $self->layer_count;
                Slic3r::debugf "  looking for neighbors on layer %d...\n", $n;
                
                my @neighbor_surfaces = @{$self->layers->[$n]->surfaces};
                my @neighbor_fill_surfaces = @{$self->layers->[$n]->fill_surfaces};
                
                # find intersection between neighbor and current layer's surfaces
                # intersections have contours and holes
                my $new_internal_solid = intersection_ex(
                    $surfaces_p,
                    [ map $_->p, grep { $_->surface_type == S_TYPE_INTERNAL || $_->surface_type == S_TYPE_INTERNALSOLID } @neighbor_surfaces ],
                    undef, 1,
                );
                next if !@$new_internal_solid;
                
                # internal-solid are the union of the existing internal-solid surfaces
                # and new ones
                my $internal_solid = union_ex([
                    ( map $_->p, grep $_->surface_type == S_TYPE_INTERNALSOLID, @neighbor_fill_surfaces ),
                    ( map @$_, @$new_internal_solid ),
                ]);
                
                # subtract intersections from layer surfaces to get resulting inner surfaces
                my $internal = diff_ex(
                    [ map $_->p, grep $_->surface_type == S_TYPE_INTERNAL, @neighbor_fill_surfaces ],
                    [ map @$_, @$internal_solid ],
                    1,
                );
                Slic3r::debugf "    %d internal-solid and %d internal surfaces found\n",
                    scalar(@$internal_solid), scalar(@$internal);
                
                # Note: due to floating point math we're going to get some very small
                # polygons as $internal; they will be removed by removed_small_features()
                
                # assign resulting inner surfaces to layer
                my $neighbor_fill_surfaces = $self->layers->[$n]->fill_surfaces;
                @$neighbor_fill_surfaces = ();
                push @$neighbor_fill_surfaces, Slic3r::Surface->new
                    (expolygon => $_, surface_type => S_TYPE_INTERNAL)
                    for @$internal;
                
                # assign new internal-solid surfaces to layer
                push @$neighbor_fill_surfaces, Slic3r::Surface->new
                    (expolygon => $_, surface_type => S_TYPE_INTERNALSOLID)
                    for @$internal_solid;
                
                # assign top and bottom surfaces to layer
                foreach my $s (Slic3r::Surface->group(grep { $_->surface_type == S_TYPE_TOP || $_->surface_type == S_TYPE_BOTTOM } @neighbor_fill_surfaces)) {
                    my $solid_surfaces = diff_ex(
                        [ map $_->p, @$s ],
                        [ map @$_, @$internal_solid, @$internal ],
                        1,
                    );
                    push @$neighbor_fill_surfaces, Slic3r::Surface->new
                        (expolygon => $_, surface_type => $s->[0]->surface_type, bridge_angle => $s->[0]->bridge_angle)
                        for @$solid_surfaces;
                }
            }
        }
        
        @{$layer->fill_surfaces} = grep $_->expolygon->area > $area_threshold, @{$layer->fill_surfaces};
    }
}

# combine fill surfaces across layers
sub combine_infill {
    my $self = shift;
    return unless $Slic3r::Config->infill_every_layers > 1 && $Slic3r::Config->fill_density > 0;
    
    my $area_threshold = scale($Slic3r::flow->spacing) ** 2;
    
    # start from bottom, skip first layer
    for (my $i = 1; $i < $self->layer_count; $i++) {
        my $layer = $self->layer($i);
        
        # skip layer if no internal fill surfaces
        next if !grep $_->surface_type == S_TYPE_INTERNAL, @{$layer->fill_surfaces};
        
        # for each possible depth, look for intersections with the lower layer
        # we do this from the greater depth to the smaller
        for (my $d = $Slic3r::Config->infill_every_layers - 1; $d >= 1; $d--) {
            next if ($i - $d) < 0;
            my $lower_layer = $self->layer($i - 1);
            
            # select surfaces of the lower layer having the depth we're looking for
            my @lower_surfaces = grep $_->depth_layers == $d && $_->surface_type == S_TYPE_INTERNAL,
                @{$lower_layer->fill_surfaces};
            next if !@lower_surfaces;
            
            # calculate intersection between our surfaces and theirs
            my $intersection = intersection_ex(
                [ map $_->p, grep $_->depth_layers <= $d, @lower_surfaces ],
                [ map $_->p, grep $_->surface_type == S_TYPE_INTERNAL, @{$layer->fill_surfaces} ],
                undef, 1,
            );
            
            # purge intersections, skip tiny regions
            @$intersection = grep $_->area > $area_threshold, @$intersection;
            next if !@$intersection;
            
            # new fill surfaces of the current layer are:
            # - any non-internal surface
            # - intersections found (with a $d + 1 depth)
            # - any internal surface not belonging to the intersection (with its original depth)
            {
                my @new_surfaces = ();
                push @new_surfaces, grep $_->surface_type != S_TYPE_INTERNAL, @{$layer->fill_surfaces};
                push @new_surfaces, map Slic3r::Surface->new
                    (expolygon => $_, surface_type => S_TYPE_INTERNAL, depth_layers => $d + 1), @$intersection;
                
                foreach my $depth (reverse $d..$Slic3r::Config->infill_every_layers) {
                    push @new_surfaces, map Slic3r::Surface->new
                        (expolygon => $_, surface_type => S_TYPE_INTERNAL, depth_layers => $depth),
                        
                        # difference between our internal layers with depth == $depth
                        # and the intersection found
                        @{diff_ex(
                            [
                                map $_->p, grep $_->surface_type == S_TYPE_INTERNAL && $_->depth_layers == $depth, 
                                    @{$layer->fill_surfaces},
                            ],
                            [ map @$_, @$intersection ],
                            1,
                        )};
                }
                @{$layer->fill_surfaces} = @new_surfaces;
            }
            
            # now we remove the intersections from lower layer
            {
                my @new_surfaces = ();
                push @new_surfaces, grep $_->surface_type != S_TYPE_INTERNAL, @{$lower_layer->fill_surfaces};
                foreach my $depth (1..$Slic3r::Config->infill_every_layers) {
                    push @new_surfaces, map Slic3r::Surface->new
                        (expolygon => $_, surface_type => S_TYPE_INTERNAL, depth_layers => $depth),
                        
                        # difference between internal layers with depth == $depth
                        # and the intersection found
                        @{diff_ex(
                            [
                                map $_->p, grep $_->surface_type == S_TYPE_INTERNAL && $_->depth_layers == $depth, 
                                    @{$lower_layer->fill_surfaces},
                            ],
                            [ map @$_, @$intersection ],
                            1,
                        )};
                }
                @{$lower_layer->fill_surfaces} = @new_surfaces;
            }
            
            
        }
    }
}

sub generate_support_material {
    my $self = shift;
    my %params = @_;
    
    my $threshold_rad           = deg2rad($Slic3r::Config->support_material_threshold + 1);   # +1 makes the threshold inclusive
    my $overhang_width          = $threshold_rad == 0 ? undef : scale $Slic3r::Config->layer_height * ((cos $threshold_rad) / (sin $threshold_rad));
    my $distance_from_object    = 1.5 * scale $Slic3r::support_material_flow->width;
    
    # determine support regions in each layer (for upper layers)
    Slic3r::debugf "Detecting regions\n";
    my %layers = ();
    {
        my @current_support_regions = ();   # expolygons we've started to support (i.e. below the empty interface layers)
        my @queue = ();                     # the number of items of this array determines the number of empty interface layers
        for my $i (reverse 0 .. $#{$self->layers}) {
            my $layer = $self->layers->[$i];
            my $lower_layer = $i > 0 ? $self->layers->[$i-1] : undef;
            
            # step 1: generate support material in current layer (for upper layers)
            push @current_support_regions, @{ shift @queue } if @queue && $i < $#{$self->layers};
            
            @current_support_regions = @{diff_ex(
                [ map @$_, @current_support_regions ],
                [ map @{$_->expolygon}, @{$layer->slices} ],
            )};
            
            $layers{$i} = diff_ex(
                [ map @$_, @current_support_regions ],
                [ map @$_, map $_->expolygon->offset_ex($distance_from_object),  @{$layer->slices} ],
            );
            $_->simplify(scale $Slic3r::support_material_flow->spacing * 2) for @{$layers{$i}};
            
            # step 2: get layer overhangs and put them into queue for adding support inside lower layers
            # we need an angle threshold for this
            my @overhangs = ();
            if ($lower_layer) {
                @overhangs = map $_->offset_ex(2 * $overhang_width), @{diff_ex(
                    [ map @$_, map $_->expolygon->offset_ex(-$overhang_width), @{$layer->slices} ],
                    [ map @{$_->expolygon}, @{$lower_layer->slices} ],
                    1,
                )};
            }
            push @queue, [@overhangs];
        }
    }
    return if !map @$_, values %layers;
    
    # generate paths for the pattern that we're going to use
    Slic3r::debugf "Generating patterns\n";
    my $support_patterns = [];  # in case we want cross-hatching
    {
        # 0.5 makes sure the paths don't get clipped externally when applying them to layers
        my @support_material_areas = map $_->offset_ex(- 0.5 * scale $Slic3r::support_material_flow->width),
            @{union_ex([ map $_->contour, map @$_, values %layers ])};
        
        my $fill = Slic3r::Fill->new(print => $params{print});
        my $filler = $fill->filler($Slic3r::Config->support_material_pattern);
        $filler->angle($Slic3r::Config->support_material_angle);
        {
            my @patterns = ();
            foreach my $expolygon (@support_material_areas) {
                my @paths = $filler->fill_surface(
                    Slic3r::Surface->new(expolygon => $expolygon),
                    density         => $Slic3r::support_material_flow->spacing / $Slic3r::Config->support_material_spacing,
                    flow_spacing    => $Slic3r::support_material_flow->spacing,
                );
                my $params = shift @paths;
                
                push @patterns,
                    map Slic3r::ExtrusionPath->new(
                        polyline        => Slic3r::Polyline->new(@$_),
                        role            => EXTR_ROLE_SUPPORTMATERIAL,
                        depth_layers    => 1,
                        flow_spacing    => $params->{flow_spacing},
                    ), @paths;
            }
            push @$support_patterns, [@patterns];
        }
    
        if (0) {
            require "Slic3r/SVG.pm";
            Slic3r::SVG::output(undef, "support_$_.svg",
                polylines        => [ map $_->polyline, map @$_, $support_patterns->[$_] ],
                polygons         => [ map @$_, @support_material_areas ],
            ) for 0 .. $#$support_patterns;
        }
    }
    
    # apply the pattern to layers
    Slic3r::debugf "Applying patterns\n";
    {
        my $clip_pattern = sub {
            my ($layer_id, $expolygons) = @_;
            my @paths = ();
            foreach my $expolygon (@$expolygons) {
                push @paths,
                    map $_->pack,
                    map $_->clip_with_expolygon($expolygon),
                    map $_->clip_with_polygon($expolygon->bounding_box_polygon),
                    @{$support_patterns->[ $layer_id % @$support_patterns ]};
            };
            return @paths;
        };
        my %layer_paths = ();
        Slic3r::parallelize(
            items => [ keys %layers ],
            thread_cb => sub {
                my $q = shift;
                my $paths = {};
                while (defined (my $layer_id = $q->dequeue)) {
                    $paths->{$layer_id} = [ $clip_pattern->($layer_id, $layers{$layer_id}) ];
                }
                return $paths;
            },
            collect_cb => sub {
                my $paths = shift;
                $layer_paths{$_} = $paths->{$_} for keys %$paths;
            },
            no_threads_cb => sub {
                $layer_paths{$_} = [ $clip_pattern->($_, $layers{$_}) ] for keys %layers;
            },
        );
        
        foreach my $layer_id (keys %layer_paths) {
            my $layer = $self->layers->[$layer_id];
            $layer->support_fills(Slic3r::ExtrusionPath::Collection->new);
            push @{$layer->support_fills->paths}, @{$layer_paths{$layer_id}};
        }
    }
}

1;