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More tests and related fixes to bridge detection. #1917

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This commit is contained in:
Alessandro Ranellucci 2014-04-21 20:44:21 +02:00
parent c4bfe64fb8
commit f7e8a99078
3 changed files with 50 additions and 30 deletions
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48
lib/Slic3r/Layer/BridgeDetector.pm
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@ -1,19 +1,20 @@
package Slic3r::Layer::BridgeDetector;
use Moo;
use List::Util qw(first sum);
use Slic3r::Geometry qw(PI scaled_epsilon rad2deg epsilon);
use List::Util qw(first sum max);
use Slic3r::Geometry qw(PI unscale scaled_epsilon rad2deg epsilon);
use Slic3r::Geometry::Clipper qw(intersection_pl intersection_ex);
has 'lower_slices' => (is => 'rw', required => 1); # ExPolygons or ExPolygonCollection
has 'perimeter_flow' => (is => 'rw', required => 1);
has 'infill_flow' => (is => 'rw', required => 1);
has 'resolution' => (is => 'rw', default => sub { PI/36 });
sub detect_angle {
my ($self, $expolygon) = @_;
my $grown = $expolygon->offset(+$self->perimeter_flow->scaled_width);
my $anchors_offset = $self->infill_flow->scaled_width;
my $grown = $expolygon->offset(+$anchors_offset);
my @lower = @{$self->lower_slices}; # expolygons
# detect what edges lie on lower slices
@ -55,8 +56,10 @@ sub detect_angle {
$bridge_angle = $line->direction;
}
} elsif (@edges) {
# inset the bridge expolygon; we'll use this one to clip our test lines
my $inset = $expolygon->offset_ex($self->infill_flow->scaled_width);
# 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 = $expolygon->offset_ex(+$anchors_offset/2);
# detect anchors as intersection between our bridge expolygon and the lower slices
my $anchors = intersection_ex(
@ -69,14 +72,15 @@ sub detect_angle {
# 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
my %directions = (); # angle => score
my %directions_coverage = (); # angle => score
my %directions_avg_length = (); # angle => score
my $line_increment = $self->infill_flow->scaled_width;
for (my $angle = 0; $angle < PI; $angle += $self->resolution) {
my $my_inset = [ map $_->clone, @$inset ];
my $my_anchors = [ map $_->clone, @$anchors ];
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 @$my_inset, @$my_anchors;
$_->rotate($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 ]);
@ -89,7 +93,7 @@ sub detect_angle {
);
}
my @clipped_lines = map Slic3r::Line->new(@$_), @{ intersection_pl(\@lines, [ map @$_, @$my_inset ]) };
my @clipped_lines = map Slic3r::Line->new(@$_), @{ intersection_pl(\@lines, [ map @$_, @$my_clip_area ]) };
# remove any line not having both endpoints within anchors
# NOTE: these calls to contains_point() probably need to check whether the point
@ -100,14 +104,28 @@ sub detect_angle {
&& (first { $_->contains_point($line->b) } @$my_anchors);
} @clipped_lines;
my @lengths = map $_->length, @clipped_lines;
# sum length of bridged lines
$directions{$angle} = sum(map $_->length, @clipped_lines) // 0;
$directions_coverage{$angle} = sum(@lengths) // 0;
# max length of bridged lines
$directions_avg_length{$angle} = @lengths ? (max(@lengths)) : -1;
}
# this could be slightly optimized with a max search instead of the sort
my @sorted_directions = sort { $directions{$a} <=> $directions{$b} } keys %directions;
# 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->infill_flow->scaled_width) {
$cmp = $directions_avg_length{$b} <=> $directions_avg_length{$a};
} else {
$cmp = ($coverage_diff > 0) ? 1 : -1;
}
$cmp;
} keys %directions_coverage;
# the best direction is the one causing most lines to be bridged
$bridge_angle = $sorted_directions[-1];
}
}

1
lib/Slic3r/Layer/Region.pm
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@ -399,7 +399,6 @@ sub process_external_surfaces {
if ($lower_layer) {
$bridge_detector //= Slic3r::Layer::BridgeDetector->new(
lower_slices => $lower_layer->slices,
perimeter_flow => $self->flow(FLOW_ROLE_PERIMETER),
infill_flow => $self->flow(FLOW_ROLE_INFILL),
);
Slic3r::debugf "Processing bridge at layer %d:\n", $self->id;

21
t/bridges.t
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@ -1,4 +1,4 @@
use Test::More tests => 8;
use Test::More tests => 12;
use strict;
use warnings;
@ -9,14 +9,14 @@ BEGIN {
use List::Util qw(first);
use Slic3r;
use Slic3r::Geometry qw(scale epsilon rad2deg PI);
use Slic3r::Geometry qw(scale epsilon deg2rad rad2deg PI);
use Slic3r::Test;
my $full_test = sub {
my ($bd) = @_;
{
my $test = sub {
my ($bridge_size, $expected_angle) = @_;
my ($bridge_size, $rotate, $expected_angle, $tolerance) = @_;
my ($x, $y) = @$bridge_size;
my $lower = Slic3r::ExPolygon->new(
@ -24,16 +24,19 @@ my $full_test = sub {
Slic3r::Polygon->new_scale([0,0], [0,$y], [$x,$y], [$x,0]),
);
$lower->translate(scale 20, scale 20); # avoid negative coordinates for easier SVG preview
$lower->rotate(deg2rad($rotate), [$x/2,$y/2]);
my $bridge = $lower->[1]->clone;
$bridge->reverse;
$bridge = Slic3r::ExPolygon->new($bridge);
$bd->lower_slices([$lower]);
ok check_angle($bd, $bridge, $expected_angle), 'correct bridge angle for O-shaped overhang';
ok check_angle($bd, $bridge, $expected_angle, $tolerance), 'correct bridge angle for O-shaped overhang';
};
$test->([20,10], 90);
$test->([10,20], 0);
$test->([20,10], 0, 0);
$test->([10,20], 0, 90);
$test->([20,10], 45, 135, 20);
$test->([20,10], 135, 45, 20);
}
{
@ -73,7 +76,6 @@ my $full_test = sub {
my $flow = Slic3r::Flow->new(width => 0.5, spacing => 0.45, nozzle_diameter => 0.5);
my $bd = Slic3r::Layer::BridgeDetector->new(
lower_slices => [],
perimeter_flow => $flow,
infill_flow => $flow,
);
@ -85,13 +87,14 @@ $full_test->($bd);
sub check_angle {
my ($bd, $bridge, $expected) = @_;
my ($bd, $bridge, $expected, $tolerance) = @_;
$tolerance //= rad2deg($bd->resolution) + epsilon;
my $result = $bd->detect_angle($bridge);
# our epsilon is equal to the steps used by the bridge detection algorithm
###use XXX; YYY [ rad2deg($result), $expected ];
return defined $result && abs(rad2deg($result) - $expected) < rad2deg($bd->resolution);
return defined $result && abs(rad2deg($result) - $expected) < $tolerance;
}
__END__