3D-printing/OrcaSlicer
1
0
Fork 0
mirror of https://github.com/SoftFever/OrcaSlicer.git synced 2025-07-19 20:57:53 -06:00
Code Issues Projects Releases Packages Wiki Activity Actions 1

Reworked the bridge detector to allow searching a single bridging

Browse source 
direction over multiple regions. This allows a single bridge to be
drawn over holes, which are too close to each other to allow
for separate bridges.
Fixes Bridging-Angle not optimal
https://github.com/prusa3d/Slic3r/issues/12

Re-allowed adaptive infill line width for solid infills. The adaptive
infill line width works in some circumstances, see Issue #15,
but the original implementation often changed the line width too
aggressively. The current implementation limits the line width change
to 20%.
Fixes Gaps between infill and perimeter leads to errors in laydown on following layer
https://github.com/prusa3d/Slic3r/issues/15
This commit is contained in:
bubnikv 2016-11-08 09:59:25 +01:00
parent 5a81731577
commit 22ca927f12
7 changed files with 433 additions and 443 deletions
Download patch file Download diff file Expand all files Collapse all files

391
xs/src/libslic3r/BridgeDetector.cpp
View file

@ -5,37 +5,48 @@
namespace Slic3r {
class BridgeDirectionComparator {
public:
std::map<double,double> dir_coverage; // angle => score
BridgeDirectionComparator(double _extrusion_width)
: extrusion_width(_extrusion_width)
{};
// the best direction is the one causing most lines to be bridged (thus most coverage)
bool operator() (double a, double b) {
// Initial sort by coverage only - comparator must obey strict weak ordering
return (this->dir_coverage[a] > this->dir_coverage[b]);
};
private:
double extrusion_width;
};
BridgeDetector::BridgeDetector(const ExPolygon &_expolygon, const ExPolygonCollection &_lower_slices,
coord_t _extrusion_width)
: expolygon(_expolygon), lower_slices(_lower_slices), extrusion_width(_extrusion_width),
resolution(PI/36.0), angle(-1)
BridgeDetector::BridgeDetector(
ExPolygon _expolygon,
const ExPolygonCollection &_lower_slices,
coord_t _spacing) :
// The original infill polygon, not inflated.
expolygons(expolygons_owned),
// All surfaces of the object supporting this region.
lower_slices(_lower_slices),
spacing(_spacing)
{
/* outset our bridge by an arbitrary amout; we'll use this outer margin
for detecting anchors */
Polygons grown;
offset((Polygons)this->expolygon, &grown, this->extrusion_width);
this->expolygons_owned.push_back(std::move(_expolygon));
initialize();
}
BridgeDetector::BridgeDetector(
const ExPolygons &_expolygons,
const ExPolygonCollection &_lower_slices,
coord_t _spacing) :
// The original infill polygon, not inflated.
expolygons(_expolygons),
// All surfaces of the object supporting this region.
lower_slices(_lower_slices),
spacing(_spacing)
{
initialize();
}
void BridgeDetector::initialize()
{
// 5 degrees stepping
this->resolution = PI/36.0;
// output angle not known
this->angle = -1.;
// Outset our bridge by an arbitrary amout; we'll use this outer margin for detecting anchors.
Polygons grown = offset(this->expolygons, float(this->spacing));
// detect what edges lie on lower slices by turning bridge contour and holes
// into polylines and then clipping them with each lower slice's contour
intersection(grown, this->lower_slices.contours(), &this->_edges);
// Detect possible anchoring edges of this bridging region.
// Detect what edges lie on lower slices by turning bridge contour and holes
// into polylines and then clipping them with each lower slice's contour.
// Currently _edges are only used to set a candidate direction of the bridge (see bridge_direction_candidates()).
intersection(to_polylines(grown), this->lower_slices.contours(), &this->_edges);
#ifdef SLIC3R_DEBUG
printf(" bridge has " PRINTF_ZU " support(s)\n", this->_edges.size());
@ -43,7 +54,7 @@ BridgeDetector::BridgeDetector(const ExPolygon &_expolygon, const ExPolygonColle
// detect anchors as intersection between our bridge expolygon and the lower slices
// safety offset required to avoid Clipper from detecting empty intersection while Boost actually found some edges
intersection(grown, this->lower_slices, &this->_anchors, true);
this->_anchor_regions = intersection_ex(grown, to_polygons(this->lower_slices.expolygons), true);
/*
if (0) {
@ -60,18 +71,103 @@ BridgeDetector::BridgeDetector(const ExPolygon &_expolygon, const ExPolygonColle
bool
BridgeDetector::detect_angle()
{
if (this->_edges.empty() || this->_anchors.empty()) return false;
if (this->_edges.empty() || this->_anchor_regions.empty())
// The bridging region is completely in the air, there are no anchors available at the layer below.
return false;
std::vector<BridgeDirection> candidates;
{
std::vector<double> angles = bridge_direction_candidates();
candidates.reserve(angles.size());
for (size_t i = 0; i < angles.size(); ++ i)
candidates.push_back(BridgeDirection(angles[i]));
}
/* 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. */
Polygons clip_area;
offset((const Slic3r::Polygons)this->expolygon, &clip_area, +this->extrusion_width/2);
Polygons clip_area = offset(this->expolygons, 0.5f * float(this->spacing));
/* 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 */
bool have_coverage = false;
for (size_t i_angle = 0; i_angle < candidates.size(); ++ i_angle)
{
const double angle = candidates[i_angle].angle;
Lines lines;
{
// Get an oriented bounding box around _anchor_regions.
BoundingBox bbox = get_extents_rotated(this->_anchor_regions, - angle);
// Cover the region with line segments.
lines.reserve((bbox.max.y - bbox.min.y + this->spacing) / this->spacing);
double s = sin(angle);
double c = cos(angle);
//FIXME Vojtech: The lines shall be spaced half the line width from the edge, but then
// some of the test cases fail. Need to adjust the test cases then?
// for (coord_t y = bbox.min.y + this->spacing / 2; y <= bbox.max.y; y += this->spacing)
for (coord_t y = bbox.min.y; y <= bbox.max.y; y += this->spacing)
lines.push_back(Line(
Point((coord_t)round(c * bbox.min.x - s * y), (coord_t)round(c * y + s * bbox.min.x)),
Point((coord_t)round(c * bbox.max.x - s * y), (coord_t)round(c * y + s * bbox.max.x))));
}
double total_length = 0;
double max_length = 0;
{
Lines clipped_lines = intersection(lines, clip_area);
for (size_t i = 0; i < clipped_lines.size(); ++i) {
const Line &line = clipped_lines[i];
if (expolygons_contain(this->_anchor_regions, line.a) && expolygons_contain(this->_anchor_regions, line.b)) {
// This line could be anchored.
double len = line.length();
total_length += len;
max_length = std::max(max_length, len);
}
}
}
if (total_length == 0.)
continue;
have_coverage = true;
// Sum length of bridged lines.
candidates[i_angle].coverage = total_length;
/* 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
candidates[i_angle].max_length = max_length;
}
// if no direction produced coverage, then there's no bridge direction
if (! have_coverage)
return false;
// sort directions by coverage - most coverage first
std::sort(candidates.begin(), candidates.end());
// if any other direction is within extrusion width of coverage, prefer it if shorter
// TODO: There are two options here - within width of the angle with most coverage, or within width of the currently perferred?
size_t i_best = 0;
for (size_t i = 1; i < candidates.size() && candidates[i_best].coverage - candidates[i].coverage < this->spacing; ++ i)
if (candidates[i].max_length < candidates[i_best].max_length)
i_best = i;
this->angle = candidates[i_best].angle;
if (this->angle >= PI)
this->angle -= PI;
#ifdef SLIC3R_DEBUG
printf(" Optimal infill angle is %d degrees\n", (int)Slic3r::Geometry::rad2deg(this->angle));
#endif
return true;
}
std::vector<double> BridgeDetector::bridge_direction_candidates() const
{
// we test angles according to configured resolution
std::vector<double> angles;
for (int i = 0; i <= PI/this->resolution; ++i)
@ -79,20 +175,16 @@ BridgeDetector::detect_angle()
// we also test angles of each bridge contour
{
Polygons pp = this->expolygon;
for (Polygons::const_iterator p = pp.begin(); p != pp.end(); ++p) {
Lines lines = p->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line)
angles.push_back(line->direction());
}
Lines lines = to_lines(this->expolygons);
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line)
angles.push_back(line->direction());
}
/* we also test angles of each open supporting edge
(this finds the optimal angle for C-shaped supports) */
for (Polylines::const_iterator edge = this->_edges.begin(); edge != this->_edges.end(); ++edge) {
if (edge->first_point().coincides_with(edge->last_point())) continue;
angles.push_back(Line(edge->first_point(), edge->last_point()).direction());
}
for (Polylines::const_iterator edge = this->_edges.begin(); edge != this->_edges.end(); ++edge)
if (! edge->first_point().coincides_with(edge->last_point()))
angles.push_back(Line(edge->first_point(), edge->last_point()).direction());
// remove duplicates
double min_resolution = PI/180.0; // 1 degree
@ -107,91 +199,8 @@ BridgeDetector::detect_angle()
in case they are parallel (PI, 0) */
if (Slic3r::Geometry::directions_parallel(angles.front(), angles.back(), min_resolution))
angles.pop_back();
BridgeDirectionComparator bdcomp(this->extrusion_width);
std::map<double,double> dir_avg_length;
double line_increment = this->extrusion_width;
bool have_coverage = false;
for (std::vector<double>::const_iterator angle = angles.begin(); angle != angles.end(); ++angle) {
Polygons my_clip_area = clip_area;
ExPolygons my_anchors = this->_anchors;
// rotate everything - the center point doesn't matter
for (Polygons::iterator it = my_clip_area.begin(); it != my_clip_area.end(); ++it)
it->rotate(-*angle, Point(0,0));
for (ExPolygons::iterator it = my_anchors.begin(); it != my_anchors.end(); ++it)
it->rotate(-*angle, Point(0,0));
// generate lines in this direction
BoundingBox bb;
for (ExPolygons::const_iterator it = my_anchors.begin(); it != my_anchors.end(); ++it)
bb.merge((Points)*it);
Lines lines;
for (coord_t y = bb.min.y; y <= bb.max.y; y += line_increment)
lines.push_back(Line(Point(bb.min.x, y), Point(bb.max.x, y)));
Lines clipped_lines;
intersection(lines, my_clip_area, &clipped_lines);
// remove any line not having both endpoints within anchors
for (size_t i = 0; i < clipped_lines.size(); ++i) {
Line &line = clipped_lines[i];
if (!Slic3r::Geometry::contains(my_anchors, line.a)
|| !Slic3r::Geometry::contains(my_anchors, line.b)) {
clipped_lines.erase(clipped_lines.begin() + i);
--i;
}
}
std::vector<double> lengths;
double total_length = 0;
for (Lines::const_iterator line = clipped_lines.begin(); line != clipped_lines.end(); ++line) {
double len = line->length();
lengths.push_back(len);
total_length += len;
}
if (total_length) have_coverage = true;
// sum length of bridged lines
bdcomp.dir_coverage[*angle] = total_length;
/* 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
dir_avg_length[*angle] = !lengths.empty()
? *std::max_element(lengths.begin(), lengths.end())
: 0;
}
// if no direction produced coverage, then there's no bridge direction
if (!have_coverage) return false;
// sort directions by coverage - most coverage first
std::sort(angles.begin(), angles.end(), bdcomp);
this->angle = angles.front();
// if any other direction is within extrusion width of coverage, prefer it if shorter
// TODO: There are two options here - within width of the angle with most coverage, or within width of the currently perferred?
double most_coverage_angle = this->angle;
for (std::vector<double>::const_iterator angle = angles.begin() + 1;
angle != angles.end() && bdcomp.dir_coverage[most_coverage_angle] - bdcomp.dir_coverage[*angle] < this->extrusion_width;
++angle
) {
if (dir_avg_length[*angle] < dir_avg_length[this->angle]) {
this->angle = *angle;
}
}
if (this->angle >= PI) this->angle -= PI;
#ifdef SLIC3R_DEBUG
printf(" Optimal infill angle is %d degrees\n", (int)Slic3r::Geometry::rad2deg(this->angle));
#endif
return true;
return angles;
}
void
@ -199,58 +208,48 @@ BridgeDetector::coverage(double angle, Polygons* coverage) const
{
if (angle == -1) angle = this->angle;
if (angle == -1) return;
// Clone our expolygon and rotate it so that we work with vertical lines.
ExPolygon expolygon = this->expolygon;
expolygon.rotate(PI/2.0 - angle, Point(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. */
ExPolygons grown;
offset(expolygon, &grown, this->extrusion_width/2.0);
// Compute trapezoids according to a vertical orientation
Polygons trapezoids;
for (ExPolygons::const_iterator it = grown.begin(); it != grown.end(); ++it)
it->get_trapezoids2(&trapezoids, PI/2.0);
// get anchors, convert them to Polygons and rotate them too
Polygons anchors;
for (ExPolygons::const_iterator anchor = this->_anchors.begin(); anchor != this->_anchors.end(); ++anchor) {
Polygons pp = *anchor;
for (Polygons::iterator p = pp.begin(); p != pp.end(); ++p)
p->rotate(PI/2.0 - angle, Point(0,0));
anchors.insert(anchors.end(), pp.begin(), pp.end());
}
// Get anchors, convert them to Polygons and rotate them.
Polygons anchors = to_polygons(this->_anchor_regions);
polygons_rotate(anchors, PI/2.0 - angle);
Polygons covered;
for (Polygons::const_iterator trapezoid = trapezoids.begin(); trapezoid != trapezoids.end(); ++trapezoid) {
Lines lines = trapezoid->lines();
Lines supported;
intersection(lines, anchors, &supported);
for (ExPolygons::const_iterator it_expoly = this->expolygons.begin(); it_expoly != this->expolygons.end(); ++ it_expoly)
{
// Clone our expolygon and rotate it so that we work with vertical lines.
ExPolygon expolygon = *it_expoly;
expolygon.rotate(PI/2.0 - angle);
// not nice, we need a more robust non-numeric check
for (size_t i = 0; i < supported.size(); ++i) {
if (supported[i].length() < this->extrusion_width) {
supported.erase(supported.begin() + i);
i--;
}
/* 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. */
ExPolygons grown = offset_ex(expolygon, 0.5f * float(this->spacing));
// Compute trapezoids according to a vertical orientation
Polygons trapezoids;
for (ExPolygons::const_iterator it = grown.begin(); it != grown.end(); ++it)
it->get_trapezoids2(&trapezoids, PI/2.0);
for (Polygons::iterator trapezoid = trapezoids.begin(); trapezoid != trapezoids.end(); ++trapezoid) {
Lines supported = intersection(trapezoid->lines(), anchors);
size_t n_supported = 0;
// not nice, we need a more robust non-numeric check
for (size_t i = 0; i < supported.size(); ++i)
if (supported[i].length() >= this->spacing)
++ n_supported;
if (n_supported >= 2)
covered.push_back(STDMOVE(*trapezoid));
}
if (supported.size() >= 2) covered.push_back(*trapezoid);
}
// merge trapezoids and rotate them back
Polygons _coverage;
union_(covered, &_coverage);
for (Polygons::iterator p = _coverage.begin(); p != _coverage.end(); ++p)
p->rotate(-(PI/2.0 - angle), Point(0,0));
// intersect trapezoids with actual bridge area to remove extra margins
// and append it to result
intersection(_coverage, this->expolygon, coverage);
// Unite the trapezoids before rotation, as the rotation creates tiny gaps and intersections between the trapezoids
// instead of exact overlaps.
covered = union_(covered);
// Intersect trapezoids with actual bridge area to remove extra margins and append it to result.
polygons_rotate(covered, -(PI/2.0 - angle));
intersection(covered, to_polygons(this->expolygons), coverage);
/*
if (0) {
my @lines = map @{$_->lines}, @$trapezoids;
@ -260,7 +259,7 @@ BridgeDetector::coverage(double angle, Polygons* coverage) const
Slic3r::SVG::output(
"coverage_" . rad2deg($angle) . ".svg",
expolygons => [$self->expolygon],
green_expolygons => $self->_anchors,
green_expolygons => $self->_anchor_regions,
red_expolygons => $coverage,
lines => \@lines,
);
@ -284,29 +283,21 @@ BridgeDetector::unsupported_edges(double angle, Polylines* unsupported) const
{
if (angle == -1) angle = this->angle;
if (angle == -1) return;
// get bridge edges (both contour and holes)
Polylines bridge_edges;
{
Polygons pp = this->expolygon;
bridge_edges.insert(bridge_edges.end(), pp.begin(), pp.end()); // this uses split_at_first_point()
}
// get unsupported edges
Polygons grown_lower;
offset(this->lower_slices, &grown_lower, +this->extrusion_width);
Polylines _unsupported;
diff(bridge_edges, grown_lower, &_unsupported);
/* 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)
double angle_tolerance = PI / 180.0 * 5.0; */
for (Polylines::const_iterator polyline = _unsupported.begin(); polyline != _unsupported.end(); ++polyline) {
Lines lines = polyline->lines();
for (Lines::const_iterator line = lines.begin(); line != lines.end(); ++line) {
Polygons grown_lower = offset(this->lower_slices.expolygons, float(this->spacing));
for (ExPolygons::const_iterator it_expoly = this->expolygons.begin(); it_expoly != this->expolygons.end(); ++ it_expoly) {
// get unsupported bridge edges (both contour and holes)
Polylines unuspported_polylines;
diff(to_polylines(*it_expoly), grown_lower, &unuspported_polylines);
Lines unsupported_lines = to_lines(unuspported_polylines);
/* 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)
double angle_tolerance = PI / 180.0 * 5.0; */
for (Lines::const_iterator line = unsupported_lines.begin(); line != unsupported_lines.end(); ++line) {
if (!Slic3r::Geometry::directions_parallel(line->direction(), angle))
unsupported->push_back(*line);
}
@ -318,7 +309,7 @@ BridgeDetector::unsupported_edges(double angle, Polylines* unsupported) const
Slic3r::SVG::output(
"unsupported_" . rad2deg($angle) . ".svg",
expolygons => [$self->expolygon],
green_expolygons => $self->_anchors,
green_expolygons => $self->_anchor_regions,
red_expolygons => union_ex($grown_lower),
no_arrows => 1,
polylines => \@bridge_edges,