BambuStudio/libslic3r/Fill/FillCrossHatch.cpp

233 lines
8.6 KiB
C++

#include "../ClipperUtils.hpp"
#include "../ShortestPath.hpp"
#include "../Surface.hpp"
#include <cmath>
#include "FillCrossHatch.hpp"
namespace Slic3r {
// CrossHatch Infill: Enhances 3D Printing Speed & Reduces Noise
// CrossHatch, as its name hints, alternates line direction by 90 degrees every few layers to improve adhesion.
// It introduces transform layers between direction shifts for better line cohesion, which fixes the weakness of line infill.
// The transform technique is inspired by David Eccles, improved 3D honeycomb but we made a more flexible implementation.
// This method notably increases printing speed, meeting the demands of modern high-speed 3D printers, and reduces noise for most layers.
// By Bambu Lab
// graph credits: David Eccles (gringer).
// But we made a different definition for points.
/* o---o
* / \
* / \
* \ /
* \ /
* o---o
* p1 p2 p3 p4
*/
static Pointfs generate_one_cycle(double progress, coordf_t period)
{
Pointfs out;
double offset = progress * 1. / 8. * period;
out.reserve(4);
out.push_back(Vec2d(0.25 * period - offset, offset));
out.push_back(Vec2d(0.25 * period + offset, offset));
out.push_back(Vec2d(0.75 * period - offset, -offset));
out.push_back(Vec2d(0.75 * period + offset, -offset));
return out;
}
static Polylines generate_transform_pattern(double inprogress, int direction, coordf_t ingrid_size, coordf_t inwidth, coordf_t inheight)
{
coordf_t width = inwidth;
coordf_t height = inheight;
coordf_t grid_size = ingrid_size * 2; // we due with odd and even saparately.
double progress = inprogress;
Polylines out_polylines;
// generate template patterns;
Pointfs one_cycle_points = generate_one_cycle(progress, grid_size);
Polyline one_cycle;
one_cycle.points.reserve(one_cycle_points.size());
for (size_t i = 0; i < one_cycle_points.size(); i++) one_cycle.points.push_back(Point(one_cycle_points[i]));
// swap if vertical
if (direction < 0) {
width = height;
height = inwidth;
}
// replicate polylines;
Polylines odd_polylines;
Polyline odd_poly;
int num_of_cycle = width / grid_size + 2;
odd_poly.points.reserve(num_of_cycle * one_cycle.size());
// replicate to odd line
Point translate = Point(0, 0);
for (size_t i = 0; i < num_of_cycle; i++) {
Polyline odd_points;
odd_points = Polyline(one_cycle);
odd_points.translate(Point(i * grid_size, 0.0));
odd_poly.points.insert(odd_poly.points.end(), odd_points.begin(), odd_points.end());
}
// fill the height
int num_of_lines = height / grid_size + 2;
odd_polylines.reserve(num_of_lines * odd_poly.size());
for (size_t i = 0; i < num_of_lines; i++) {
Polyline poly = odd_poly;
poly.translate(Point(0.0, grid_size * i));
odd_polylines.push_back(poly);
}
// save to output
out_polylines.insert(out_polylines.end(), odd_polylines.begin(), odd_polylines.end());
// replicate to even lines
Polylines even_polylines;
even_polylines.reserve(odd_polylines.size());
for (size_t i = 0; i < odd_polylines.size(); i++) {
Polyline even = odd_poly;
even.translate(Point(-0.5 * grid_size, (i + 0.5) * grid_size));
even_polylines.push_back(even);
}
// save for output
out_polylines.insert(out_polylines.end(), even_polylines.begin(), even_polylines.end());
// change to vertical if need
if (direction < 0) {
// swap xy, see if we need better performance method
for (Polyline &poly : out_polylines) {
for (Point &p : poly) { std::swap(p.x(), p.y()); }
}
}
return out_polylines;
}
static Polylines generate_repeat_pattern(int direction, coordf_t grid_size, coordf_t inwidth, coordf_t inheight)
{
coordf_t width = inwidth;
coordf_t height = inheight;
Polylines out_polylines;
// swap if vertical
if (direction < 0) {
width = height;
height = inwidth;
}
int num_of_lines = height / grid_size + 1;
out_polylines.reserve(num_of_lines);
for (int i = 0; i < num_of_lines; i++) {
Polyline poly;
poly.points.reserve(2);
poly.append(Point(coordf_t(0), coordf_t(grid_size * i)));
poly.append(Point(width, coordf_t(grid_size * i)));
out_polylines.push_back(poly);
}
// change to vertical if needed
if (direction < 0) {
// swap xy
for (Polyline &poly : out_polylines) {
for (Point &p : poly) { std::swap(p.x(), p.y()); }
}
}
return out_polylines;
}
// it makes the real patterns that overlap the bounding box
// repeat_ratio define the ratio between the height of repeat pattern and grid
static Polylines generate_infill_layers(coordf_t z_height, double repeat_ratio, coordf_t grid_size, coordf_t width, coordf_t height)
{
Polylines result;
coordf_t trans_layer_size = grid_size * 0.4; // upper.
coordf_t repeat_layer_size = grid_size * repeat_ratio; // lower.
z_height += repeat_layer_size / 2 + trans_layer_size; // offset to improve first few layer strength and reduce the risk of warpping.
coordf_t period = trans_layer_size + repeat_layer_size;
coordf_t remains = z_height - std::floor(z_height / period) * period;
coordf_t trans_z = remains - repeat_layer_size; // put repeat layer first.
coordf_t repeat_z = remains;
int phase = fmod(z_height, period * 2) - (period - 1); // add epsilon
int direction = phase <= 0 ? -1 : 1;
// this is a repeat layer
if (trans_z < 0) {
result = generate_repeat_pattern(direction, grid_size, width, height);
}
// this is a transform layer
else {
double progress = fmod(trans_z, trans_layer_size) / trans_layer_size;
// split the progress to forward and backward, with a opposite direction.
if (progress < 0.5)
result = generate_transform_pattern((progress + 0.1) * 2, direction, grid_size, width, height); // increase overlapping.
else
result = generate_transform_pattern((1.1 - progress) * 2, -1 * direction, grid_size, width, height);
}
return result;
}
void FillCrossHatch ::_fill_surface_single(
const FillParams &params, unsigned int thickness_layers, const std::pair<float, Point> &direction, ExPolygon expolygon, Polylines &polylines_out)
{
// rotate angle
auto infill_angle = float(this->angle);
if (std::abs(infill_angle) >= EPSILON) expolygon.rotate(-infill_angle);
// get the rotated bounding box
BoundingBox bb = expolygon.contour.bounding_box();
// linespace modifier
coord_t line_spacing = coord_t(scale_(this->spacing) / params.density);
// reduce density
if (params.density < 0.999) line_spacing *= 1.08;
bb.merge(align_to_grid(bb.min, Point(line_spacing * 4, line_spacing * 4)));
// generate pattern
//Orca: optimize the cross-hatch infill pattern to improve strength when low infill density is used.
double repeat_ratio = 1.0;
if (params.density < 0.3)
repeat_ratio = std::clamp(1.0 - std::exp(-5 * params.density), 0.2, 1.0);
Polylines polylines = generate_infill_layers(scale_(this->z), repeat_ratio, line_spacing, bb.size()(0), bb.size()(1));
// shift the pattern to the actual space
for (Polyline &pl : polylines) { pl.translate(bb.min); }
polylines = intersection_pl(polylines, to_polygons(expolygon));
// --- remove small remains from gyroid infill
if (!polylines.empty()) {
// Remove very small bits, but be careful to not remove infill lines connecting thin walls!
// The infill perimeter lines should be separated by around a single infill line width.
const double minlength = scale_(0.8 * this->spacing);
polylines.erase(std::remove_if(polylines.begin(), polylines.end(), [minlength](const Polyline &pl)
{ return pl.length() < minlength; }), polylines.end());
}
if (!polylines.empty()) {
int infill_start_idx = polylines_out.size(); // only rotate what belongs to us.
// connect lines
if (params.dont_connect() || polylines.size() <= 1)
append(polylines_out, chain_polylines(std::move(polylines)));
else
this->connect_infill(std::move(polylines), expolygon, polylines_out, this->spacing, params);
// rotate back
if (std::abs(infill_angle) >= EPSILON) {
for (auto it = polylines_out.begin() + infill_start_idx; it != polylines_out.end(); ++it) it->rotate(infill_angle);
}
}
}
} // namespace Slic3r