Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

extra_perimeters : now add perimeters for overhangs. #4717

Open
wants to merge 1 commit into
base: master
Choose a base branch
from
Open

extra_perimeters : now add perimeters for overhangs. #4717

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
60 changes: 42 additions & 18 deletions xs/src/libslic3r/BridgeDetector.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -181,15 +181,11 @@ BridgeDetector::detect_angle()
}

Polygons
BridgeDetector::coverage() const
{
if (this->angle == -1) return Polygons();
return this->coverage(this->angle);
}

Polygons
BridgeDetector::coverage(double angle) const
BridgeDetector::coverage(double angle, bool precise) const
{
if (angle == -1) angle = this->angle;
if (angle == -1) return Polygons();

// 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));
Expand All @@ -214,18 +210,46 @@ BridgeDetector::coverage(double angle) const
}

Polygons covered;
for (const Polygon &trapezoid : trapezoids) {
Lines supported = intersection_ln(trapezoid.lines(), anchors);
for (Polygon &trapezoid : trapezoids) {

// 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--;
}
}
size_t n_supported = 0;
if (!precise) {
// not nice, we need a more robust non-numeric check
for (const Line &supported_line : intersection_ln(trapezoid.lines(), anchors))
if (supported_line.length() >= this->extrusion_width)
++n_supported;
} else {
Polygons intersects = intersection(trapezoid, anchors);
n_supported = intersects.size();

if (n_supported >= 2) {
// trim it to not allow to go outside of the intersections
BoundingBox center_bound = intersects[0].bounding_box();
coord_t min_y = center_bound.center().y, max_y = center_bound.center().y;
for (const Polygon &poly_bound : intersects) {
center_bound = poly_bound.bounding_box();
if (min_y > center_bound.center().y) min_y = center_bound.center().y;
if (max_y < center_bound.center().y) max_y = center_bound.center().y;
}
coord_t min_x = trapezoid[0].x, max_x = trapezoid[0].x;
for (const Point &p : trapezoid.points) {
if (min_x > p.x) min_x = p.x;
if (max_x < p.x) max_x = p.x;
}
//add what get_trapezoids3 has removed (+EPSILON)
min_x -= (this->extrusion_width / 4 + 1);
max_x += (this->extrusion_width / 4 + 1);
coord_t mid_x = (min_x + max_x) / 2;
for (Point &p : trapezoid.points) {
if (p.y < min_y) p.y = min_y;
if (p.y > max_y) p.y = max_y;
if (p.x > min_x && p.x < mid_x) p.x = min_x;
if (p.x < max_x && p.x > mid_x) p.x = max_x;
}
}
}

if (supported.size() >= 2) covered.push_back(trapezoid);
if (n_supported >= 2) covered.push_back(trapezoid);
}

// merge trapezoids and rotate them back
Expand Down
3 changes: 1 addition & 2 deletions xs/src/libslic3r/BridgeDetector.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -23,8 +23,7 @@ class BridgeDetector {

BridgeDetector(const ExPolygon &_expolygon, const ExPolygonCollection &_lower_slices, coord_t _extrusion_width);
bool detect_angle();
Polygons coverage() const;
Polygons coverage(double angle) const;
Polygons coverage(double angle = -1, bool precise = false) const;

/// Return the bridge edges that are not currently supported but would permit use of the supplied
/// bridge angle if it was supported.
Expand Down
3 changes: 2 additions & 1 deletion xs/src/libslic3r/GCode.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -305,7 +305,8 @@ GCode::extrude(ExtrusionLoop loop, std::string description, double speed)
// next copies (if any) would not detect the correct orientation

// extrude all loops ccw
bool was_clockwise = loop.make_counter_clockwise();
// no! this was decided by the generator, he know better than us.
bool was_clockwise = false;// loop.make_counter_clockwise();

SeamPosition seam_position = this->config.seam_position;
if (loop.role == elrSkirt) seam_position = spNearest;
Expand Down
96 changes: 85 additions & 11 deletions xs/src/libslic3r/PerimeterGenerator.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
@@ -1,5 +1,6 @@
#include "PerimeterGenerator.hpp"
#include "ClipperUtils.hpp"
#include "BridgeDetector.hpp"
#include "ExtrusionEntityCollection.hpp"
#include <cmath>
#include <cassert>
Expand Down Expand Up @@ -69,7 +70,7 @@ PerimeterGenerator::process()
loops = min_loops;
}

const int loop_number = loops-1; // 0-indexed loops
int loop_number = loops-1; // 0-indexed loops


Polygons gaps;
Expand All @@ -80,6 +81,52 @@ PerimeterGenerator::process()
std::vector<PerimeterGeneratorLoops> contours(loop_number+1); // depth => loops
std::vector<PerimeterGeneratorLoops> holes(loop_number+1); // depth => loops
ThickPolylines thin_walls;


// We can add more perimeters if there are uncovered overhangs
bool has_overhang = false;
if (this->config->extra_perimeters && !last.empty()
&& this->lower_slices != NULL && !this->lower_slices->expolygons.empty()){
//split the polygons with bottom/notbottom
ExPolygons unsupported = diff_ex(last, to_polygons(this->lower_slices->expolygons), true);
if (!unsupported.empty()) {
//only consider overhangs and let bridges alone
int numploy = 0;
//only consider the bottom layer that intersect unsupported, to be sure it's only on our island.
ExPolygonCollection lower_island(diff_ex(last, to_polygons(unsupported), true));
Polygons bridges;
for(ExPolygon &one_hole : unsupported){
BridgeDetector detector(one_hole,
lower_island,
pspacing);
if (detector.detect_angle()) {
Polygons hole_bridges = detector.coverage(detector.angle, true);
bridges.insert(bridges.end(), hole_bridges.begin(), hole_bridges.end());
}
}
//now that we have detected the bridges, we can see if we have an overhang area
if (!bridges.empty()) {
ExPolygons bridgeable = union_ex(bridges);
//simplify to avoid most of artefacts from printing lines.
ExPolygons bridgeable_simplified;
for (ExPolygon &poly : bridgeable) {
poly.simplify(pspacing / 2, &bridgeable_simplified);
}

if (!bridgeable_simplified.empty())
bridgeable_simplified = offset_ex(bridgeable_simplified, pspacing/1.9);
if (!bridgeable_simplified.empty()) {
//offset by perimeter spacing because the simplify may have reduced it a bit.
unsupported = diff_ex(unsupported, bridgeable_simplified, true);
}
}
if (!unsupported.empty()) {
//allow to add an other perimeter
has_overhang = true;
}
}
}


// we loop one time more than needed in order to find gaps after the last perimeter was applied
for (int i = 0; i <= loop_number+1; ++i) { // outer loop is 0
Expand Down Expand Up @@ -181,19 +228,43 @@ PerimeterGenerator::process()
}
}

if (offsets.empty()) break;
if (i > loop_number) break; // we were only looking for gaps this time
// if (offsets.empty()) break;
// if (i > loop_number) break; // we were only looking for gaps this time

last = offsets;
for (Polygons::const_iterator polygon = offsets.begin(); polygon != offsets.end(); ++polygon) {
PerimeterGeneratorLoop loop(*polygon, i);
loop.is_contour = polygon->is_counter_clockwise();
if (loop.is_contour) {
contours[i].push_back(loop);
if (offsets.empty()) {
// Store the number of loops actually generated.
loop_number = i - 1;
break;
} else if (i > loop_number) {
if (has_overhang) {
loop_number++;
contours.emplace_back();
holes.emplace_back();
} else {
holes[i].push_back(loop);
// If i > loop_number, we were looking just for gaps.
break;
}
}

for (const Polygon &polygon : offsets) {
if(polygon.is_counter_clockwise()){
contours[i].emplace_back(PerimeterGeneratorLoop(polygon, i, true, has_overhang));
}else{
holes[i].emplace_back(PerimeterGeneratorLoop(polygon, i, false, has_overhang));
}
}
last = std::move(offsets);

// last = offsets;
// for (Polygons::const_iterator polygon = offsets.begin(); polygon != offsets.end(); ++polygon) {
// PerimeterGeneratorLoop loop(*polygon, i);
// loop.is_contour = polygon->is_counter_clockwise();
// if (loop.is_contour) {
// contours[i].push_back(loop);
// } else {
// holes[i].push_back(loop);
// }
// }
}

// nest loops: holes first
Expand Down Expand Up @@ -450,7 +521,10 @@ PerimeterGenerator::_traverse_loops(const PerimeterGeneratorLoops &loops,

ExtrusionEntityCollection children = this->_traverse_loops(loop.children, thin_walls);
if (loop.is_contour) {
eloop.make_counter_clockwise();
if (loop.is_overhang && this->layer_id % 2 == 1)
eloop.make_clockwise();
else
eloop.make_counter_clockwise();
entities.append(children.entities);
entities.append(eloop);
} else {
Expand Down
6 changes: 6 additions & 0 deletions xs/src/libslic3r/PerimeterGenerator.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -19,11 +19,17 @@ class PerimeterGeneratorLoop {
// Is it a contour or a hole?
// Contours are CCW oriented, holes are CW oriented.
bool is_contour;
//overhang may need to be reversed
bool is_overhang;
// Depth in the hierarchy. External perimeter has depth = 0. An external perimeter could be both a contour and a hole.
unsigned short depth;
// Children contour, may be both CCW and CW oriented (outer contours or holes).
std::vector<PerimeterGeneratorLoop> children;

PerimeterGeneratorLoop(Polygon polygon, unsigned short depth, bool is_contour) :
polygon(polygon), is_contour(is_contour), depth(depth), is_overhang(false) {}
PerimeterGeneratorLoop(Polygon polygon, unsigned short depth, bool is_contour, bool is_overhang) :
polygon(polygon), is_contour(is_contour), depth(depth), is_overhang(is_overhang) {}
PerimeterGeneratorLoop(Polygon polygon, unsigned short depth)
: polygon(polygon), is_contour(false), depth(depth)
{};
Expand Down