PrusaSlicer-NonPlainar/lib/Slic3r/Layer/Region.pm
2013-07-16 09:49:34 +02:00

580 lines
24 KiB
Perl

package Slic3r::Layer::Region;
use Moo;
use List::Util qw(sum first);
use Slic3r::ExtrusionPath ':roles';
use Slic3r::Geometry qw(PI A B scale chained_path_items points_coincide);
use Slic3r::Geometry::Clipper qw(safety_offset union_ex diff_ex intersection_ex
offset offset2 offset2_ex PFT_EVENODD union_pt traverse_pt diff intersection);
use Slic3r::Surface ':types';
has 'layer' => (
is => 'ro',
weak_ref => 1,
required => 1,
trigger => 1,
handles => [qw(id slice_z print_z height flow)],
);
has 'region' => (is => 'ro', required => 1, handles => [qw(extruders)]);
has 'perimeter_flow' => (is => 'rw');
has 'infill_flow' => (is => 'rw');
has 'solid_infill_flow' => (is => 'rw');
has 'top_infill_flow' => (is => 'rw');
has 'infill_area_threshold' => (is => 'lazy');
has 'overhang_width' => (is => 'lazy');
# collection of surfaces generated by slicing the original geometry
# divided by type top/bottom/internal
has 'slices' => (is => 'rw', default => sub { Slic3r::Surface::Collection->new });
# collection of polygons or polylines representing thin walls contained
# in the original geometry
has 'thin_walls' => (is => 'rw', default => sub { [] });
# collection of polygons or polylines representing thin infill regions that
# need to be filled with a medial axis
has 'thin_fills' => (is => 'rw', default => sub { [] });
# collection of surfaces for infill generation
has 'fill_surfaces' => (is => 'rw', default => sub { Slic3r::Surface::Collection->new });
# ordered collection of extrusion paths/loops to build all perimeters
has 'perimeters' => (is => 'rw', default => sub { [] });
# ordered collection of extrusion paths to fill surfaces
has 'fills' => (is => 'rw', default => sub { [] });
sub BUILD {
my $self = shift;
$self->_update_flows;
}
sub _trigger_layer {
my $self = shift;
$self->_update_flows;
}
sub _update_flows {
my $self = shift;
return if !$self->region;
if ($self->id == 0) {
for (qw(perimeter infill solid_infill top_infill)) {
my $method = "${_}_flow";
$self->$method
($self->region->first_layer_flows->{$_} || $self->region->flows->{$_});
}
} else {
$self->perimeter_flow($self->region->flows->{perimeter});
$self->infill_flow($self->region->flows->{infill});
$self->solid_infill_flow($self->region->flows->{solid_infill});
$self->top_infill_flow($self->region->flows->{top_infill});
}
}
sub _build_overhang_width {
my $self = shift;
my $threshold_rad = PI/2 - atan2($self->perimeter_flow->width / $self->height / 2, 1);
return scale($self->height * ((cos $threshold_rad) / (sin $threshold_rad)));
}
sub _build_infill_area_threshold {
my $self = shift;
return $self->solid_infill_flow->scaled_spacing ** 2;
}
# build polylines from lines
sub make_surfaces {
my $self = shift;
my ($loops) = @_;
return if !@$loops;
$self->slices->clear;
$self->slices->append(_merge_loops($loops));
# detect thin walls by offsetting slices by half extrusion inwards
if ($Slic3r::Config->thin_walls) {
my $width = $self->perimeter_flow->scaled_width;
my $diff = diff_ex(
[ map $_->p, @{$self->slices} ],
[ offset2([ map @$_, map $_->expolygon, @{$self->slices} ], -$width, +$width) ],
1,
);
$self->thin_walls([]);
if (@$diff) {
my $area_threshold = $self->perimeter_flow->scaled_spacing ** 2;
@$diff = grep $_->area > ($area_threshold), @$diff;
@{$self->thin_walls} = map $_->medial_axis($self->perimeter_flow->scaled_width), @$diff;
Slic3r::debugf " %d thin walls detected\n", scalar(@{$self->thin_walls}) if @{$self->thin_walls};
}
}
if (0) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output("surfaces.svg",
polygons => [ map $_->contour, @{$self->slices} ],
red_polygons => [ map $_->p, map @{$_->holes}, @{$self->slices} ],
);
}
}
sub _merge_loops {
my ($loops, $safety_offset) = @_;
# Input loops are not suitable for evenodd nor nonzero fill types, as we might get
# two consecutive concentric loops having the same winding order - and we have to
# respect such order. In that case, evenodd would create wrong inversions, and nonzero
# would ignore holes inside two concentric contours.
# So we're ordering loops and collapse consecutive concentric loops having the same
# winding order.
# TODO: find a faster algorithm for this.
my @loops = sort { $a->encloses_point($b->[0]) ? 0 : 1 } @$loops; # outer first
$safety_offset //= scale 0.0499;
@loops = @{ safety_offset(\@loops, $safety_offset) };
my $expolygons = [];
while (defined (my $loop = shift @loops)) {
if ($loop->is_counter_clockwise) {
$expolygons = union_ex([ $loop, map @$_, @$expolygons ]);
} else {
$expolygons = diff_ex([ map @$_, @$expolygons ], [$loop]);
}
}
$expolygons = [ map $_->offset_ex(-$safety_offset), @$expolygons ];
Slic3r::debugf " %d surface(s) having %d holes detected from %d polylines\n",
scalar(@$expolygons), scalar(map $_->holes, @$expolygons), scalar(@$loops);
return map Slic3r::Surface->new(expolygon => Slic3r::ExPolygon->new(@$_), surface_type => S_TYPE_INTERNAL), @$expolygons;
}
sub make_perimeters {
my $self = shift;
my $perimeter_spacing = $self->perimeter_flow->scaled_spacing;
my $infill_spacing = $self->solid_infill_flow->scaled_spacing;
my $gap_area_threshold = $self->perimeter_flow->scaled_width ** 2;
$self->perimeters([]);
$self->fill_surfaces->clear;
$self->thin_fills([]);
my @contours = (); # array of Polygons with ccw orientation
my @holes = (); # array of Polygons with cw orientation
my @gaps = (); # array of ExPolygons
# we need to process each island separately because we might have different
# extra perimeters for each one
foreach my $surface (@{$self->slices}) {
# detect how many perimeters must be generated for this island
my $loop_number = $Slic3r::Config->perimeters + ($surface->extra_perimeters || 0);
# generate loops
# (one more than necessary so that we can detect gaps even after the desired
# number of perimeters has been generated)
my @last = @{$surface->expolygon};
for my $i (0 .. $loop_number) {
# external loop only needs half inset distance
my $spacing = ($i == 0)
? $perimeter_spacing / 2
: $perimeter_spacing;
my @offsets = offset2_ex(\@last, -1.5*$spacing, +0.5*$spacing);
my @contours_offsets = map $_->contour, @offsets;
my @holes_offsets = map $_->holes, @offsets;
@offsets = (@contours_offsets, @holes_offsets); # turn @offsets from ExPolygons to Polygons
# where offset2() collapses the expolygon, then there's no room for an inner loop
# and we can extract the gap for later processing
if ($Slic3r::Config->gap_fill_speed > 0 && $Slic3r::Config->fill_density > 0) {
my $diff = diff_ex(
[ offset(\@last, -0.5*$spacing) ],
# +2 on the offset here makes sure that Clipper float truncation
# won't shrink the clip polygon to be smaller than intended.
[ offset(\@offsets, +0.5*$spacing + 2) ],
);
push @gaps, grep $_->area >= $gap_area_threshold, @$diff;
}
last if !@offsets || $i == $loop_number;
push @contours, @contours_offsets;
push @holes, @holes_offsets;
@last = @offsets;
}
# create one more offset to be used as boundary for fill
# we offset by half the perimeter spacing (to get to the actual infill boundary)
# and then we offset back and forth by the infill spacing to only consider the
# non-collapsing regions
# use a bogus surface_type
$self->fill_surfaces->append(
map Slic3r::Surface->new(expolygon => $_, surface_type => S_TYPE_TOP), offset2_ex(
[ map $_->simplify(&Slic3r::SCALED_RESOLUTION), @last ],
-($perimeter_spacing/2 + $infill_spacing),
+$infill_spacing,
)
);
}
$self->_fill_gaps(\@gaps);
# find nesting hierarchies separately for contours and holes
my $contours_pt = union_pt(\@contours, PFT_EVENODD);
my $holes_pt = union_pt(\@holes, PFT_EVENODD);
# prepare a coderef for traversing the PolyTree object
# external contours are root items of $contours_pt
# internal contours are the ones next to external
my $traverse;
$traverse = sub {
my ($polynodes, $depth, $is_contour) = @_;
# use a nearest neighbor search to order these children
# TODO: supply second argument to chained_path_items() too?
my @nodes = @{Slic3r::Geometry::chained_path_items(
[ map [ ($_->{outer} ? $_->{outer}[0] : $_->{hole}[0]), $_ ], @$polynodes ],
)};
my @loops = ();
foreach my $polynode (@nodes) {
push @loops, $traverse->($polynode->{children}, $depth+1, $is_contour);
# 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
my $polygon = Slic3r::Polygon->new(defined $polynode->{outer} ? @{$polynode->{outer}} : reverse @{$polynode->{hole}});
$polygon->reverse if !$is_contour;
my $role = EXTR_ROLE_PERIMETER;
if ($is_contour ? $depth == 0 : !@{ $polynode->{children} }) {
# external perimeters are root level in case of contours
# and items with no children in case of holes
$role = EXTR_ROLE_EXTERNAL_PERIMETER;
} elsif ($depth == 1 && $is_contour) {
$role = EXTR_ROLE_CONTOUR_INTERNAL_PERIMETER;
}
push @loops, Slic3r::ExtrusionLoop->new(
polygon => $polygon,
role => $role,
flow_spacing => $self->perimeter_flow->spacing,
);
}
return @loops;
};
# order loops from inner to outer (in terms of object slices)
my @loops = (
(reverse $traverse->($holes_pt, 0)),
$traverse->($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 $Slic3r::Config->external_perimeters_first
|| ($self->layer->id == 0 && $Slic3r::Config->brim_width > 0);
# append perimeters
push @{ $self->perimeters }, @loops;
# add thin walls as perimeters
push @{ $self->perimeters }, Slic3r::ExtrusionPath::Collection->new(paths => [
map {
Slic3r::ExtrusionPath->new(
polyline => ($_->isa('Slic3r::Polygon') ? $_->split_at_first_point : $_),
role => EXTR_ROLE_EXTERNAL_PERIMETER,
flow_spacing => $self->perimeter_flow->spacing,
);
} @{ $self->thin_walls }
])->chained_path;
}
sub _fill_gaps {
my $self = shift;
my ($gaps) = @_;
return unless @$gaps;
my $filler = $self->layer->object->fill_maker->filler('rectilinear');
$filler->layer_id($self->layer->id);
# we should probably use this code to handle thin walls and remove that logic from
# make_surfaces(), but we need to enable dynamic extrusion width before as we can't
# use zigzag for thin walls.
# in the mean time we subtract thin walls from the detected gaps so that we don't
# reprocess them, causing overlapping thin walls and zigzag.
@$gaps = @{diff_ex(
[ map @$_, @$gaps ],
[ map $_->grow($self->perimeter_flow->scaled_width), @{$self->{thin_walls}} ],
1,
)};
# medial axis-based gap fill should benefit from detection of larger gaps too, so
# we could try with 1.5*$w for example, but that doesn't work well for zigzag fill
# because it tends to create very sparse points along the gap when the infill direction
# is not parallel to the gap (1.5*$w thus may only work well with a straight line)
my $w = $self->perimeter_flow->width;
my @widths = ($w, 0.4 * $w); # worth trying 0.2 too?
foreach my $width (@widths) {
my $flow = $self->perimeter_flow->clone(width => $width);
# extract the gaps having this width
my @this_width = map $_->offset_ex(+0.5*$flow->scaled_width),
map $_->noncollapsing_offset_ex(-0.5*$flow->scaled_width),
@$gaps;
if (0) { # remember to re-enable t/dynamic.t
# fill gaps using dynamic extrusion width, by treating them like thin polygons,
# thus generating the skeleton and using it to fill them
my %path_args = (
role => EXTR_ROLE_SOLIDFILL,
flow_spacing => $flow->spacing,
);
push @{ $self->thin_fills }, map {
$_->isa('Slic3r::Polygon')
? Slic3r::ExtrusionLoop->new(polygon => $_, %path_args)->split_at_first_point # we should keep these as loops
: Slic3r::ExtrusionPath->new(polyline => $_, %path_args),
} map $_->medial_axis($flow->scaled_width), @this_width;
Slic3r::debugf " %d gaps filled with extrusion width = %s\n", scalar @this_width, $width
if @{ $self->thin_fills };
} else {
# fill gaps using zigzag infill
# since this is infill, we have to offset by half-extrusion width inwards
my @infill = map $_->offset_ex(-0.5*$flow->scaled_width), @this_width;
foreach my $expolygon (@infill) {
my @paths = $filler->fill_surface(
Slic3r::Surface->new(expolygon => $expolygon, surface_type => S_TYPE_INTERNALSOLID),
density => 1,
flow_spacing => $flow->spacing,
);
my $params = shift @paths;
push @{ $self->thin_fills },
map {
$_->simplify($flow->scaled_width/3);
$_;
}
map Slic3r::ExtrusionPath->new(
polyline => Slic3r::Polyline->new(@$_),
role => EXTR_ROLE_GAPFILL,
height => $self->height,
flow_spacing => $params->{flow_spacing},
), @paths;
}
}
# check what's left
@$gaps = @{diff_ex(
[ map @$_, @$gaps ],
[ map @$_, @this_width ],
)};
}
}
sub prepare_fill_surfaces {
my $self = shift;
# if no solid layers are requested, turn top/bottom surfaces to internal
if ($Slic3r::Config->top_solid_layers == 0) {
$_->surface_type(S_TYPE_INTERNAL) for grep $_->surface_type == S_TYPE_TOP, @{$self->fill_surfaces};
}
if ($Slic3r::Config->bottom_solid_layers == 0) {
$_->surface_type(S_TYPE_INTERNAL) for grep $_->surface_type == S_TYPE_BOTTOM, @{$self->fill_surfaces};
}
# turn too small internal regions into solid regions according to the user setting
if ($Slic3r::Config->fill_density > 0) {
my $min_area = scale scale $Slic3r::Config->solid_infill_below_area; # scaling an area requires two calls!
my @small = grep $_->surface_type == S_TYPE_INTERNAL && $_->expolygon->contour->area <= $min_area, @{$self->fill_surfaces};
$_->surface_type(S_TYPE_INTERNALSOLID) for @small;
Slic3r::debugf "identified %d small solid surfaces at layer %d\n", scalar(@small), $self->id if @small > 0;
}
}
sub process_external_surfaces {
my $self = shift;
# enlarge top and bottom surfaces
{
# get all external surfaces
my @top = grep $_->surface_type == S_TYPE_TOP, @{$self->fill_surfaces};
my @bottom = grep $_->surface_type == S_TYPE_BOTTOM, @{$self->fill_surfaces};
# if we're slicing with no infill, we can't extend external surfaces
# over non-existent infill
my @fill_boundaries = $Slic3r::Config->fill_density > 0
? @{$self->fill_surfaces}
: grep $_->surface_type != S_TYPE_INTERNAL, @{$self->fill_surfaces};
# offset them and intersect the results with the actual fill boundaries
my $margin = scale 3; # TODO: ensure this is greater than the total thickness of the perimeters
@top = @{intersection_ex(
[ Slic3r::Geometry::Clipper::offset([ map $_->p, @top ], +$margin) ],
[ map $_->p, @fill_boundaries ],
undef,
1, # to ensure adjacent expolygons are unified
)};
@bottom = @{intersection_ex(
[ Slic3r::Geometry::Clipper::offset([ map $_->p, @bottom ], +$margin) ],
[ map $_->p, @fill_boundaries ],
undef,
1, # to ensure adjacent expolygons are unified
)};
# give priority to bottom surfaces
@top = @{diff_ex(
[ map @$_, @top ],
[ map @$_, @bottom ],
)};
# generate new surfaces
my @new_surfaces = ();
push @new_surfaces, map Slic3r::Surface->new(
expolygon => $_,
surface_type => S_TYPE_TOP,
), @top;
push @new_surfaces, map Slic3r::Surface->new(
expolygon => $_,
surface_type => S_TYPE_BOTTOM,
), @bottom;
# subtract the new top surfaces from the other non-top surfaces and re-add them
my @other = grep $_->surface_type != S_TYPE_TOP && $_->surface_type != S_TYPE_BOTTOM, @{$self->fill_surfaces};
foreach my $group (Slic3r::Surface->group(@other)) {
push @new_surfaces, map $_->clone, map $group->[0]->clone(expolygon => $_), @{diff_ex(
[ map $_->p, @$group ],
[ map $_->p, @new_surfaces ],
)};
}
$self->fill_surfaces->clear;
$self->fill_surfaces->append(@new_surfaces);
}
# detect bridge direction (skip bottom layer)
$self->_detect_bridges if $self->id > 0;
}
sub _detect_bridges {
my $self = shift;
my @bottom = grep $_->surface_type == S_TYPE_BOTTOM, @{$self->fill_surfaces}; # surfaces
my @lower = @{$self->layer->object->layers->[ $self->id - 1 ]->slices}; # expolygons
foreach my $surface (@bottom) {
# detect what edges lie on lower slices
my @edges = (); # polylines
foreach my $lower (@lower) {
# turn bridge contour and holes into polylines and then clip them
# with each lower slice's contour
my @clipped = map $_->split_at_first_point->clip_with_polygon($lower->contour), @{$surface->expolygon};
if (@clipped == 2) {
# If the split_at_first_point() call above happens to split the polygon inside the clipping area
# we would get two consecutive polylines instead of a single one, so we use this ugly hack to
# recombine them back into a single one in order to trigger the @edges == 2 logic below.
# This needs to be replaced with something way better.
if (points_coincide($clipped[0][0], $clipped[-1][-1])) {
@clipped = (Slic3r::Polyline->new(@{$clipped[-1]}, @{$clipped[0]}));
}
if (points_coincide($clipped[-1][0], $clipped[0][-1])) {
@clipped = (Slic3r::Polyline->new(@{$clipped[0]}, @{$clipped[1]}));
}
}
push @edges, @clipped;
}
Slic3r::debugf "Found bridge on layer %d with %d support(s)\n", $self->id, scalar(@edges);
next if !@edges;
my $bridge_angle = undef;
if (0) {
require "Slic3r/SVG.pm";
Slic3r::SVG::output("bridge_$surface.svg",
expolygons => [ $surface->expolygon ],
red_expolygons => [ @lower ],
polylines => [ @edges ],
);
}
if (@edges == 2) {
my @chords = map Slic3r::Line->new($_->[0], $_->[-1]), @edges;
my @midpoints = map $_->midpoint, @chords;
my $line_between_midpoints = Slic3r::Line->new(@midpoints);
$bridge_angle = Slic3r::Geometry::rad2deg_dir($line_between_midpoints->direction);
} elsif (@edges == 1) {
# TODO: this case includes both U-shaped bridges and plain overhangs;
# we need a trapezoidation algorithm to detect the actual bridged area
# and separate it from the overhang area.
# in the mean time, we're treating as overhangs all cases where
# our supporting edge is a straight line
if (@{$edges[0]} > 2) {
my $line = Slic3r::Line->new($edges[0]->[0], $edges[0]->[-1]);
$bridge_angle = Slic3r::Geometry::rad2deg_dir($line->direction);
}
} elsif (@edges) {
# inset the bridge expolygon; we'll use this one to clip our test lines
my $inset = [ $surface->expolygon->offset_ex($self->infill_flow->scaled_width) ];
# detect anchors as intersection between our bridge expolygon and the lower slices
my $anchors = intersection_ex(
[ $surface->p ],
[ map @$_, @lower ],
undef,
1, # safety offset required to avoid Clipper from detecting empty intersection while Boost actually found some @edges
);
# 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 $angle_increment = PI/36; # 5°
my $line_increment = $self->infill_flow->scaled_width;
for (my $angle = 0; $angle <= PI; $angle += $angle_increment) {
# rotate everything - the center point doesn't matter
$_->rotate($angle, [0,0]) for @$inset, @$anchors;
# generate lines in this direction
my $bounding_box = Slic3r::Geometry::BoundingBox->new_from_points([ map @$_, map @$_, @$anchors ]);
my @lines = ();
for (my $x = $bounding_box->x_min; $x <= $bounding_box->x_max; $x += $line_increment) {
push @lines, [ [$x, $bounding_box->y_min], [$x, $bounding_box->y_max] ];
}
# TODO: use a multi_polygon_multi_linestring_intersection() call
my @clipped_lines = map @{ Boost::Geometry::Utils::polygon_multi_linestring_intersection($_, \@lines) }, @$inset;
# remove any line not having both endpoints within anchors
@clipped_lines = grep {
my $line = $_;
!(first { $_->encloses_point_quick($line->[A]) } @$anchors)
&& !(first { $_->encloses_point_quick($line->[B]) } @$anchors);
} @clipped_lines;
# sum length of bridged lines
$directions{-$angle} = sum(map Slic3r::Geometry::line_length($_), @clipped_lines) // 0;
}
# 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
$bridge_angle = Slic3r::Geometry::rad2deg_dir($sorted_directions[-1]);
}
Slic3r::debugf " Optimal infill angle of bridge on layer %d is %d degrees\n",
$self->id, $bridge_angle if defined $bridge_angle;
$surface->bridge_angle($bridge_angle // -1);
}
}
1;