278 lines
10 KiB
Perl
278 lines
10 KiB
Perl
package Slic3r::Layer::BridgeDetector;
|
|
use Moo;
|
|
|
|
use List::Util qw(first sum max min);
|
|
use Slic3r::Geometry qw(PI unscale scaled_epsilon rad2deg epsilon directions_parallel_within);
|
|
use Slic3r::Geometry::Clipper qw(intersection_pl intersection_ex union offset diff_pl union_ex
|
|
intersection_ppl);
|
|
|
|
has 'expolygon' => (is => 'ro', required => 1);
|
|
has 'lower_slices' => (is => 'rw', required => 1); # ExPolygons or ExPolygonCollection
|
|
has 'extrusion_width' => (is => 'rw', required => 1); # scaled
|
|
has 'resolution' => (is => 'rw', default => sub { PI/36 });
|
|
|
|
has '_edges' => (is => 'rw'); # Polylines representing the supporting edges
|
|
has '_anchors' => (is => 'rw'); # ExPolygons
|
|
has 'angle' => (is => 'rw');
|
|
|
|
sub BUILD {
|
|
my ($self) = @_;
|
|
|
|
# outset our bridge by an arbitrary amout; we'll use this outer margin
|
|
# for detecting anchors
|
|
my $grown = $self->expolygon->offset(+$self->extrusion_width);
|
|
|
|
# detect what edges lie on lower slices
|
|
$self->_edges(my $edges = []);
|
|
foreach my $lower (@{$self->lower_slices}) {
|
|
# turn bridge contour and holes into polylines and then clip them
|
|
# with each lower slice's contour
|
|
push @$edges, @{intersection_ppl($grown, [ $lower->contour ])};
|
|
}
|
|
Slic3r::debugf " bridge has %d support(s)\n", scalar(@$edges);
|
|
|
|
# detect anchors as intersection between our bridge expolygon and the lower slices
|
|
$self->_anchors(intersection_ex(
|
|
$grown,
|
|
[ map @$_, @{$self->lower_slices} ],
|
|
1, # safety offset required to avoid Clipper from detecting empty intersection while Boost actually found some @edges
|
|
));
|
|
|
|
if (0) {
|
|
require "Slic3r/SVG.pm";
|
|
Slic3r::SVG::output("bridge.svg",
|
|
expolygons => [ $self->expolygon ],
|
|
red_expolygons => $self->lower_slices,
|
|
polylines => $self->_edges,
|
|
);
|
|
}
|
|
}
|
|
|
|
sub detect_angle {
|
|
my ($self) = @_;
|
|
|
|
return undef if !@{$self->_edges};
|
|
|
|
my @edges = @{$self->_edges};
|
|
my $anchors = $self->_anchors;
|
|
|
|
if (!@$anchors) {
|
|
$self->angle(undef);
|
|
return undef;
|
|
}
|
|
|
|
# Outset the bridge expolygon by half the amount we used for detecting anchors;
|
|
# we'll use this one to clip our test lines and be sure that their endpoints
|
|
# are inside the anchors and not on their contours leading to false negatives.
|
|
my $clip_area = $self->expolygon->offset_ex(+$self->extrusion_width/2);
|
|
|
|
# we'll now try several directions using a rudimentary visibility check:
|
|
# bridge in several directions and then sum the length of lines having both
|
|
# endpoints within anchors
|
|
|
|
# we test angles according to configured resolution
|
|
my @angles = map { $_*$self->resolution } 0..(PI/$self->resolution);
|
|
|
|
# we also test angles of each bridge contour
|
|
push @angles, map $_->direction, map @{$_->lines}, @{$self->expolygon};
|
|
|
|
# we also test angles of each open supporting edge
|
|
# (this finds the optimal angle for C-shaped supports)
|
|
push @angles,
|
|
map Slic3r::Line->new($_->first_point, $_->last_point)->direction,
|
|
grep { !$_->first_point->coincides_with($_->last_point) }
|
|
@edges;
|
|
|
|
# remove duplicates
|
|
my $min_resolution = PI/180; # 1 degree
|
|
# proceed in reverse order so that when we compare first value with last one (-1)
|
|
# we remove the greatest one (PI) in case they are parallel (PI, 0)
|
|
@angles = reverse sort @angles;
|
|
for (my $i = 0; $i <= $#angles; ++$i) {
|
|
if (directions_parallel_within($angles[$i], $angles[$i-1], $min_resolution)) {
|
|
splice @angles, $i, 1;
|
|
--$i;
|
|
}
|
|
}
|
|
|
|
my %directions_coverage = (); # angle => score
|
|
my %directions_avg_length = (); # angle => score
|
|
my $line_increment = $self->extrusion_width;
|
|
my %unique_angles = map { $_ => 1 } @angles;
|
|
for my $angle (@angles) {
|
|
my $my_clip_area = [ map $_->clone, @$clip_area ];
|
|
my $my_anchors = [ map $_->clone, @$anchors ];
|
|
|
|
# rotate everything - the center point doesn't matter
|
|
$_->rotate(-$angle, [0,0]) for @$my_clip_area, @$my_anchors;
|
|
|
|
# generate lines in this direction
|
|
my $bounding_box = Slic3r::Geometry::BoundingBox->new_from_points([ map @$_, map @$_, @$my_anchors ]);
|
|
|
|
my @lines = ();
|
|
for (my $y = $bounding_box->y_min; $y <= $bounding_box->y_max; $y+= $line_increment) {
|
|
push @lines, Slic3r::Polyline->new(
|
|
[$bounding_box->x_min, $y],
|
|
[$bounding_box->x_max, $y],
|
|
);
|
|
}
|
|
|
|
my @clipped_lines = map Slic3r::Line->new(@$_), @{ intersection_pl(\@lines, [ map @$_, @$my_clip_area ]) };
|
|
|
|
# remove any line not having both endpoints within anchors
|
|
@clipped_lines = grep {
|
|
my $line = $_;
|
|
(first { $_->contains_point($line->a) } @$my_anchors)
|
|
&& (first { $_->contains_point($line->b) } @$my_anchors);
|
|
} @clipped_lines;
|
|
|
|
my @lengths = map $_->length, @clipped_lines;
|
|
|
|
# sum length of bridged lines
|
|
$directions_coverage{$angle} = sum(@lengths) // 0;
|
|
|
|
### The following produces more correct results in some cases and more broken in others.
|
|
### TODO: investigate, as it looks more reliable than line clipping.
|
|
###$directions_coverage{$angle} = sum(map $_->area, @{$self->coverage($angle)}) // 0;
|
|
|
|
# max length of bridged lines
|
|
$directions_avg_length{$angle} = @lengths ? (max(@lengths)) : -1;
|
|
}
|
|
|
|
# if no direction produced coverage, then there's no bridge direction
|
|
return undef if !defined first { $_ > 0 } values %directions_coverage;
|
|
|
|
# the best direction is the one causing most lines to be bridged (thus most coverage)
|
|
# and shortest max line length
|
|
my @sorted_directions = sort {
|
|
my $cmp;
|
|
my $coverage_diff = $directions_coverage{$a} - $directions_coverage{$b};
|
|
if (abs($coverage_diff) < $self->extrusion_width) {
|
|
$cmp = $directions_avg_length{$b} <=> $directions_avg_length{$a};
|
|
} else {
|
|
$cmp = ($coverage_diff > 0) ? 1 : -1;
|
|
}
|
|
$cmp;
|
|
} keys %directions_coverage;
|
|
|
|
$self->angle($sorted_directions[-1]);
|
|
|
|
if ($self->angle >= PI) {
|
|
$self->angle($self->angle - PI);
|
|
}
|
|
|
|
Slic3r::debugf " Optimal infill angle is %d degrees\n", rad2deg($self->angle);
|
|
|
|
return $self->angle;
|
|
}
|
|
|
|
sub coverage {
|
|
my ($self, $angle) = @_;
|
|
|
|
if (!defined $angle) {
|
|
return [] if !defined($angle = $self->angle);
|
|
}
|
|
|
|
# Clone our expolygon and rotate it so that we work with vertical lines.
|
|
my $expolygon = $self->expolygon->clone;
|
|
$expolygon->rotate(PI/2 - $angle, [0,0]);
|
|
|
|
# Outset the bridge expolygon by half the amount we used for detecting anchors;
|
|
# we'll use this one to generate our trapezoids and be sure that their vertices
|
|
# are inside the anchors and not on their contours leading to false negatives.
|
|
my $grown = $expolygon->offset_ex(+$self->extrusion_width/2);
|
|
|
|
# Compute trapezoids according to a vertical orientation
|
|
my $trapezoids = [ map @{$_->get_trapezoids2(PI/2)}, @$grown ];
|
|
|
|
# get anchors and rotate them too
|
|
my $anchors = [ map $_->clone, @{$self->_anchors} ];
|
|
$_->rotate(PI/2 - $angle, [0,0]) for @$anchors;
|
|
|
|
my @covered = (); # polygons
|
|
foreach my $trapezoid (@$trapezoids) {
|
|
my @polylines = map $_->as_polyline, @{$trapezoid->lines};
|
|
my @supported = @{intersection_pl(\@polylines, [map @$_, @$anchors])};
|
|
|
|
# not nice, we need a more robust non-numeric check
|
|
@supported = grep $_->length >= $self->extrusion_width, @supported;
|
|
|
|
if (@supported >= 2) {
|
|
push @covered, $trapezoid;
|
|
}
|
|
}
|
|
|
|
# merge trapezoids and rotate them back
|
|
my $coverage = union(\@covered);
|
|
$_->rotate(-(PI/2 - $angle), [0,0]) for @$coverage;
|
|
|
|
# intersect trapezoids with actual bridge area to remove extra margins
|
|
$coverage = intersection_ex($coverage, [ @{$self->expolygon} ]);
|
|
|
|
if (0) {
|
|
my @lines = map @{$_->lines}, @$trapezoids;
|
|
$_->rotate(-(PI/2 - $angle), [0,0]) for @lines;
|
|
|
|
require "Slic3r/SVG.pm";
|
|
Slic3r::SVG::output(
|
|
"coverage_" . rad2deg($angle) . ".svg",
|
|
expolygons => [$self->expolygon],
|
|
green_expolygons => $self->_anchors,
|
|
red_expolygons => $coverage,
|
|
lines => \@lines,
|
|
);
|
|
}
|
|
|
|
return $coverage;
|
|
}
|
|
|
|
# this method returns the bridge edges (as polylines) that are not supported
|
|
# but would allow the entire bridge area to be bridged with detected angle
|
|
# if supported too
|
|
sub unsupported_edges {
|
|
my ($self, $angle) = @_;
|
|
|
|
if (!defined $angle) {
|
|
return [] if !defined($angle = $self->angle);
|
|
}
|
|
|
|
# get bridge edges (both contour and holes)
|
|
my @bridge_edges = map $_->split_at_first_point, @{$self->expolygon};
|
|
$_->[0]->translate(1,0) for @bridge_edges; # workaround for Clipper bug, see comments in Slic3r::Polygon::clip_as_polyline()
|
|
|
|
# get unsupported edges
|
|
my $grown_lower = offset([ map @$_, @{$self->lower_slices} ], +$self->extrusion_width);
|
|
my $unsupported = diff_pl(
|
|
\@bridge_edges,
|
|
$grown_lower,
|
|
);
|
|
|
|
# split into individual segments and filter out edges parallel to the bridging angle
|
|
# TODO: angle tolerance should probably be based on segment length and flow width,
|
|
# so that we build supports whenever there's a chance that at least one or two bridge
|
|
# extrusions would be anchored within such length (i.e. a slightly non-parallel bridging
|
|
# direction might still benefit from anchors if long enough)
|
|
my $angle_tolerance = PI/180*5;
|
|
@$unsupported = map $_->as_polyline,
|
|
grep !directions_parallel_within($_->direction, $angle, $angle_tolerance),
|
|
map @{$_->lines},
|
|
@$unsupported;
|
|
|
|
if (0) {
|
|
require "Slic3r/SVG.pm";
|
|
Slic3r::SVG::output(
|
|
"unsupported_" . rad2deg($angle) . ".svg",
|
|
expolygons => [$self->expolygon],
|
|
green_expolygons => $self->_anchors,
|
|
red_expolygons => union_ex($grown_lower),
|
|
no_arrows => 1,
|
|
polylines => \@bridge_edges,
|
|
red_polylines => $unsupported,
|
|
);
|
|
}
|
|
|
|
return $unsupported;
|
|
}
|
|
|
|
1;
|