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The inwards move after an external loop was still randomly generated …
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…outwards in some cases. Perimeters are now generated with a distinct iterator for each slice. Nested islands are also correctly supported too. Various regression tests included. #2253
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@alranel
alranel committed Jan 8, 2015
1 parent af92e3d commit 406d045
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Showing 7 changed files with 181 additions and 68 deletions.
7 changes: 5 additions & 2 deletions lib/Slic3r/GCode.pm
View file
Expand Up @@ -207,8 +207,11 @@ sub extrude_loop {
my $last_path_polyline = $paths[-1]->polyline;
# detect angle between last and first segment
# the side depends on the original winding order of the polygon (left for contours, right for holes)
my @points = $was_clockwise ? (-2, 1) : (1, -2);
my $angle = Slic3r::Geometry::angle3points(@$last_path_polyline[0, @points]) / 3;
my @points = ($paths[0][1], $paths[-1][-2]);
@points = reverse @points if $was_clockwise;
my $angle = $paths[0]->first_point->ccw_angle(@points) / 3;

# turn left if contour, turn right if hole
$angle *= -1 if $was_clockwise;

# create the destination point along the first segment and rotate it
Expand Down
128 changes: 71 additions & 57 deletions lib/Slic3r/Layer/PerimeterGenerator.pm
View file
Expand Up @@ -8,17 +8,17 @@ use Slic3r::Geometry::Clipper qw(union_ex diff diff_ex intersection_ex offset of
offset_ex offset2_ex union_pt intersection_ppl diff_ppl);
use Slic3r::Surface ':types';

has 'slices' => (is => 'ro', required => 1);
has 'slices' => (is => 'ro', required => 1); # SurfaceCollection
has 'lower_slices' => (is => 'ro', required => 0);
has 'layer_height' => (is => 'ro', required => 1);
has 'layer_id' => (is => 'ro', required => 0, default => sub { -1 });
has 'perimeter_flow' => (is => 'ro', required => 1);
has 'ext_perimeter_flow' => (is => 'ro', required => 1);
has 'overhang_flow' => (is => 'ro', required => 1);
has 'solid_infill_flow' => (is => 'ro', required => 1);
has 'config' => (is => 'ro', default => sub { Slic3r::Config::Region->new });
has 'config' => (is => 'ro', default => sub { Slic3r::Config::PrintRegion->new });
has 'print_config' => (is => 'ro', default => sub { Slic3r::Config::Print->new });
has '_lower_slices_p' => (is => 'rw');
has '_lower_slices_p' => (is => 'rw', default => sub { [] });
has '_holes_pt' => (is => 'rw');
has '_ext_mm3_per_mm' => (is => 'rw');
has '_mm3_per_mm' => (is => 'rw');
Expand All @@ -34,6 +34,19 @@ has 'gap_fill' => (is => 'ro', default => sub { Slic3r::ExtrusionPath::Coll
# generated fill surfaces will be put here
has 'fill_surfaces' => (is => 'ro', default => sub { Slic3r::Surface::Collection->new });

sub BUILDARGS {
my ($class, %args) = @_;

if (my $flow = delete $args{flow}) {
$args{perimeter_flow} //= $flow;
$args{ext_perimeter_flow} //= $flow;
$args{overhang_flow} //= $flow;
$args{solid_infill_flow} //= $flow;
}

return { %args };
}

sub process {
my ($self) = @_;

Expand Down Expand Up @@ -62,13 +75,25 @@ sub process {
my $min_spacing = $pspacing * (1 - &Slic3r::INSET_OVERLAP_TOLERANCE);
my $ext_min_spacing = $ext_pspacing * (1 - &Slic3r::INSET_OVERLAP_TOLERANCE);

my @contours = (); # array of Polygons with ccw orientation
my @holes = (); # array of Polygons with cw orientation
my @thin_walls = (); # array of ExPolygons
# prepare grown lower layer slices for overhang detection
if ($self->lower_slices && $self->config->overhangs) {
# We consider overhang any part where the entire nozzle diameter is not supported by the
# lower layer, so we take lower slices and offset them by half the nozzle diameter used
# in the current layer
my $nozzle_diameter = $self->print_config->get_at('nozzle_diameter', $self->config->perimeter_extruder-1);

$self->_lower_slices_p(
offset([ map @$_, @{$self->lower_slices} ], scale +$nozzle_diameter/2)
);
}

# we need to process each island separately because we might have different
# extra perimeters for each one
foreach my $surface (@{$self->slices}) {
my @contours = (); # array of Polygons with ccw orientation
my @holes = (); # array of Polygons with cw orientation
my @thin_walls = (); # array of ExPolygons

# detect how many perimeters must be generated for this island
my $loop_number = $self->config->perimeters + ($surface->extra_perimeters || 0);

Expand Down Expand Up @@ -194,60 +219,48 @@ sub process {
-($pspacing/2 + $min_perimeter_infill_spacing/2),
+$min_perimeter_infill_spacing/2,
)};
}


# process thin walls by collapsing slices to single passes
if (@thin_walls) {
# the following offset2 ensures almost nothing in @thin_walls is narrower than $min_width
# (actually, something larger than that still may exist due to mitering or other causes)
my $min_width = $pwidth / 4;
@thin_walls = @{offset2_ex([ map @$_, @thin_walls ], -$min_width/2, +$min_width/2)};
# process thin walls by collapsing slices to single passes
if (@thin_walls) {
# the following offset2 ensures almost nothing in @thin_walls is narrower than $min_width
# (actually, something larger than that still may exist due to mitering or other causes)
my $min_width = $pwidth / 4;
@thin_walls = @{offset2_ex([ map @$_, @thin_walls ], -$min_width/2, +$min_width/2)};

# the maximum thickness of our thin wall area is equal to the minimum thickness of a single loop
$self->_thin_wall_polylines([ map @{$_->medial_axis($pwidth + $pspacing, $min_width)}, @thin_walls ]);
Slic3r::debugf " %d thin walls detected\n", scalar(@{$self->_thin_wall_polylines}) if $Slic3r::debug;
# the maximum thickness of our thin wall area is equal to the minimum thickness of a single loop
$self->_thin_wall_polylines([ map @{$_->medial_axis($pwidth + $pspacing, $min_width)}, @thin_walls ]);
Slic3r::debugf " %d thin walls detected\n", scalar(@{$self->_thin_wall_polylines}) if $Slic3r::debug;

if (0) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output(
"medial_axis.svg",
no_arrows => 1,
expolygons => \@thin_walls,
green_polylines => [ map $_->polygon->split_at_first_point, @{$self->perimeters} ],
red_polylines => $self->_thin_wall_polylines,
);
if (0) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output(
"medial_axis.svg",
no_arrows => 1,
expolygons => \@thin_walls,
green_polylines => [ map $_->polygon->split_at_first_point, @{$self->perimeters} ],
red_polylines => $self->_thin_wall_polylines,
);
}
}
}

# find nesting hierarchies separately for contours and holes
my $contours_pt = union_pt(\@contours);
$self->_holes_pt(union_pt(\@holes));

# find nesting hierarchies separately for contours and holes
my $contours_pt = union_pt(\@contours);
$self->_holes_pt(union_pt(\@holes));
# order loops from inner to outer (in terms of object slices)
my @loops = $self->_traverse_pt($contours_pt, 0, 1);

# prepare grown lower layer slices for overhang detection
my $lower_slices = Slic3r::ExPolygon::Collection->new;
if ($self->lower_slices && $self->config->overhangs) {
# We consider overhang any part where the entire nozzle diameter is not supported by the
# lower layer, so we take lower slices and offset them by half the nozzle diameter used
# in the current layer
my $nozzle_diameter = $self->print_config->get_at('nozzle_diameter', $self->config->perimeter_extruder-1);
$lower_slices->append($_)
for @{offset_ex([ map @$_, @{$self->lower_slices} ], scale +$nozzle_diameter/2)};
# if brim will be printed, reverse the order of perimeters so that
# we continue inwards after having finished the brim
# TODO: add test for perimeter order
@loops = reverse @loops
if $self->config->external_perimeters_first
|| ($self->layer_id == 0 && $self->print_config->brim_width > 0);

# append perimeters for this slice as a collection
$self->loops->append(Slic3r::ExtrusionPath::Collection->new(@loops));
}
$self->_lower_slices_p($lower_slices->polygons);

# order loops from inner to outer (in terms of object slices)
my @loops = $self->_traverse_pt($contours_pt, 0, 1);

# if brim will be printed, reverse the order of perimeters so that
# we continue inwards after having finished the brim
# TODO: add test for perimeter order
@loops = reverse @loops
if $self->config->external_perimeters_first
|| ($self->layer_id == 0 && $self->print_config->brim_width > 0);

# append perimeters
$self->loops->append($_) for @loops;
}

sub _traverse_pt {
Expand Down Expand Up @@ -328,9 +341,8 @@ sub _traverse_pt {
# return ccw contours and cw holes
# GCode.pm will convert all of them to ccw, but it needs to know
# what the holes are in order to compute the correct inwards move
# We do this on the final Loop object instead of the polygon because
# overhang clipping might have reversed its order since Clipper does
# not preserve polyline orientation.
# We do this on the final Loop object because overhang clipping
# does not keep orientation.
if ($is_contour) {
$loop->make_counter_clockwise;
} else {
Expand Down Expand Up @@ -358,10 +370,13 @@ sub _traverse_pt {

# use a nearest neighbor search to order these children
# TODO: supply second argument to chained_path() too?
# (We used to skip this chiained_path() when $is_contour &&
# (We used to skip this chained_path() when $is_contour &&
# $depth == 0 because slices are ordered at G_code export
# time, but multiple top-level perimeters might belong to
# the same slice actually, so that was a broken optimization.)
# We supply no_reverse = false because we want to permit reversal
# of thin walls, but we rely on the fact that loops will never
# be reversed anyway.
my $sorted_collection = $collection->chained_path_indices(0);
my @orig_indices = @{$sorted_collection->orig_indices};

Expand Down Expand Up @@ -407,7 +422,6 @@ sub _fill_gaps {
1,
);
my @polylines = map @{$_->medial_axis($max, $min/2)}, @$this;

return if !@polylines;

Slic3r::debugf " %d gaps filled with extrusion width = %s\n", scalar @$this, $w
Expand Down
8 changes: 4 additions & 4 deletions lib/Slic3r/Print/GCode.pm
View file
Expand Up @@ -424,17 +424,17 @@ sub process_layer {
# process perimeters
{
my $extruder_id = $region->config->perimeter_extruder-1;
foreach my $perimeter (@{$layerm->perimeters}) {
foreach my $perimeter_coll (@{$layerm->perimeters}) {
# init by_extruder item only if we actually use the extruder
$by_extruder{$extruder_id} //= [];

# $perimeter is an ExtrusionLoop or ExtrusionPath object
# $perimeter_coll is an ExtrusionPath::Collection object representing a single slice
for my $i (0 .. $#{$layer->slices}) {
if ($i == $#{$layer->slices}
|| $layer->slices->[$i]->contour->contains_point($perimeter->first_point)) {
|| $layer->slices->[$i]->contour->contains_point($perimeter_coll->first_point)) {
$by_extruder{$extruder_id}[$i] //= { perimeters => {} };
$by_extruder{$extruder_id}[$i]{perimeters}{$region_id} //= [];
push @{ $by_extruder{$extruder_id}[$i]{perimeters}{$region_id} }, $perimeter;
push @{ $by_extruder{$extruder_id}[$i]{perimeters}{$region_id} }, @$perimeter_coll;
last;
}
}
Expand Down
2 changes: 1 addition & 1 deletion lib/Slic3r/Print/SupportMaterial.pm
View file
Expand Up @@ -178,7 +178,7 @@ sub contact_area {
# TODO: split_at_first_point() could split a bridge mid-way
my @overhang_perimeters =
map { $_->isa('Slic3r::ExtrusionLoop') ? $_->polygon->split_at_first_point : $_->polyline->clone }
@{$layerm->perimeters};
map @$_, @{$layerm->perimeters};

# workaround for Clipper bug, see Slic3r::Polygon::clip_as_polyline()
$_->[0]->translate(1,0) for @overhang_perimeters;
Expand Down
91 changes: 89 additions & 2 deletions t/perimeters.t
View file
@@ -1,4 +1,4 @@
use Test::More tests => 11;
use Test::More tests => 29;
use strict;
use warnings;

Expand All @@ -7,6 +7,8 @@ BEGIN {
use lib "$FindBin::Bin/../lib";
}

use Slic3r::ExtrusionLoop ':roles';
use Slic3r::ExtrusionPath ':roles';
use List::Util qw(first);
use Slic3r;
use Slic3r::Flow ':roles';
Expand Down Expand Up @@ -188,7 +190,7 @@ use Slic3r::Test;
my $pflow = $layerm->flow(FLOW_ROLE_PERIMETER);
my $iflow = $layerm->flow(FLOW_ROLE_INFILL);
my $covered_by_perimeters = union_ex([
(map @{$_->polygon->split_at_first_point->grow($pflow->scaled_width/2)}, @{$layerm->perimeters}),
(map @{$_->polygon->split_at_first_point->grow($pflow->scaled_width/2)}, map @$_, @{$layerm->perimeters}),
]);
my $covered_by_infill = union_ex([
(map $_->p, @{$layerm->fill_surfaces}),
Expand Down Expand Up @@ -285,4 +287,89 @@ use Slic3r::Test;
$test->('small_dorito');
}

{
my $flow = Slic3r::Flow->new(
width => 1,
height => 1,
nozzle_diameter => 1,
);

my $config = Slic3r::Config->new;
my $test = sub {
my ($expolygons, %expected) = @_;

my $slices = Slic3r::Surface::Collection->new;
$slices->append(Slic3r::Surface->new(
surface_type => S_TYPE_INTERNAL,
expolygon => $_,
)) for @$expolygons;

my $g = Slic3r::Layer::PerimeterGenerator->new(
# input:
layer_height => 1,
slices => $slices,
flow => $flow,
);
$g->config->apply_dynamic($config);
$g->process;

is scalar(@{$g->loops}),
scalar(@$expolygons), 'expected number of collections';
ok !defined(first { !$_->isa('Slic3r::ExtrusionPath::Collection') } @{$g->loops}),
'everything is returned as collections';
is scalar(map @$_, @{$g->loops}),
$expected{total}, 'expected number of loops';
is scalar(grep $_->role == EXTR_ROLE_EXTERNAL_PERIMETER, map @$_, map @$_, @{$g->loops}),
$expected{external}, 'expected number of external loops';
is scalar(grep $_->role == EXTRL_ROLE_CONTOUR_INTERNAL_PERIMETER, map @$_, @{$g->loops}),
$expected{cinternal}, 'expected number of internal contour loops';
is scalar(grep $_->polygon->is_counter_clockwise, map @$_, @{$g->loops}),
$expected{ccw}, 'expected number of ccw loops';

return $g;
};

$config->set('perimeters', 3);
$test->(
[
Slic3r::ExPolygon->new(
Slic3r::Polygon->new_scale([0,0], [100,0], [100,100], [0,100]),
),
],
total => 3,
external => 1,
cinternal => 1,
ccw => 3,
);
$test->(
[
Slic3r::ExPolygon->new(
Slic3r::Polygon->new_scale([0,0], [100,0], [100,100], [0,100]),
Slic3r::Polygon->new_scale([40,40], [40,60], [60,60], [60,40]),
),
],
total => 6,
external => 2,
cinternal => 1,
ccw => 3,
);
$test->(
[
Slic3r::ExPolygon->new(
Slic3r::Polygon->new_scale([0,0], [200,0], [200,200], [0,200]),
Slic3r::Polygon->new_scale([20,20], [20,180], [180,180], [180,20]),
),
# nested:
Slic3r::ExPolygon->new(
Slic3r::Polygon->new_scale([50,50], [150,50], [150,150], [50,150]),
Slic3r::Polygon->new_scale([80,80], [80,120], [120,120], [120,80]),
),
],
total => 4*3,
external => 4,
cinternal => 2,
ccw => 2*3,
);
}

__END__
6 changes: 6 additions & 0 deletions xs/src/libslic3r/ExtrusionEntity.hpp
View file
Expand Up @@ -35,6 +35,9 @@ enum ExtrusionLoopRole {
class ExtrusionEntity
{
public:
virtual bool is_loop() const {
return false;
};
virtual ExtrusionEntity* clone() const = 0;
virtual ~ExtrusionEntity() {};
virtual void reverse() = 0;
Expand Down Expand Up @@ -84,6 +87,9 @@ class ExtrusionLoop : public ExtrusionEntity
ExtrusionLoopRole role;

ExtrusionLoop(ExtrusionLoopRole role = elrDefault) : role(role) {};
bool is_loop() const {
return true;
};
operator Polygon() const;
ExtrusionLoop* clone() const;
bool make_clockwise();
Expand Down
7 changes: 5 additions & 2 deletions xs/src/libslic3r/ExtrusionEntityCollection.cpp
View file
Expand Up @@ -37,7 +37,9 @@ void
ExtrusionEntityCollection::reverse()
{
for (ExtrusionEntitiesPtr::iterator it = this->entities.begin(); it != this->entities.end(); ++it) {
(*it)->reverse();
// Don't reverse it if it's a loop, as it doesn't change anything in terms of elements ordering
// and caller might rely on winding order
if (!(*it)->is_loop()) (*it)->reverse();
}
std::reverse(this->entities.begin(), this->entities.end());
}
Expand Down Expand Up @@ -96,7 +98,8 @@ ExtrusionEntityCollection::chained_path_from(Point start_near, ExtrusionEntityCo
int start_index = start_near.nearest_point_index(endpoints);
int path_index = start_index/2;
ExtrusionEntity* entity = my_paths.at(path_index);
if (start_index % 2 && !no_reverse) {
// never reverse loops, since it's pointless for chained path and callers might depend on orientation
if (start_index % 2 && !no_reverse && !entity->is_loop()) {
entity->reverse();
}
retval->entities.push_back(my_paths.at(path_index));
Expand Down

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