PrusaSlicer/src/libslic3r/Fill/FillAdaptive.cpp
2020-09-18 13:37:37 +02:00

721 lines
28 KiB
C++

#include "../ClipperUtils.hpp"
#include "../ExPolygon.hpp"
#include "../Surface.hpp"
#include "../Geometry.hpp"
#include "../Layer.hpp"
#include "../Print.hpp"
#include "../ShortestPath.hpp"
#include "FillAdaptive.hpp"
// for indexed_triangle_set
#include <admesh/stl.h>
#include <cstdlib>
#include <cmath>
// Boost pool: Don't use mutexes to synchronize memory allocation.
#define BOOST_POOL_NO_MT
#include <boost/pool/object_pool.hpp>
namespace Slic3r {
namespace FillAdaptive {
// Derived from https://github.com/juj/MathGeoLib/blob/master/src/Geometry/Triangle.cpp
// The AABB-Triangle test implementation is based on the pseudo-code in
// Christer Ericson's Real-Time Collision Detection, pp. 169-172. It is
// practically a standard SAT test.
//
// Original MathGeoLib benchmark:
// Best: 17.282 nsecs / 46.496 ticks, Avg: 17.804 nsecs, Worst: 18.434 nsecs
//
//FIXME Vojtech: The MathGeoLib contains a vectorized implementation.
template<typename Vector>
bool triangle_AABB_intersects(const Vector &a, const Vector &b, const Vector &c, const BoundingBoxBase<Vector> &aabb)
{
using Scalar = typename Vector::Scalar;
Vector tMin = a.cwiseMin(b.cwiseMin(c));
Vector tMax = a.cwiseMax(b.cwiseMax(c));
if (tMin.x() >= aabb.max.x() || tMax.x() <= aabb.min.x()
|| tMin.y() >= aabb.max.y() || tMax.y() <= aabb.min.y()
|| tMin.z() >= aabb.max.z() || tMax.z() <= aabb.min.z())
return false;
Vector center = (aabb.min + aabb.max) * 0.5f;
Vector h = aabb.max - center;
const Vector t[3] { b-a, c-a, c-b };
Vector ac = a - center;
Vector n = t[0].cross(t[1]);
Scalar s = n.dot(ac);
Scalar r = std::abs(h.dot(n.cwiseAbs()));
if (abs(s) >= r)
return false;
const Vector at[3] = { t[0].cwiseAbs(), t[1].cwiseAbs(), t[2].cwiseAbs() };
Vector bc = b - center;
Vector cc = c - center;
// SAT test all cross-axes.
// The following is a fully unrolled loop of this code, stored here for reference:
/*
Scalar d1, d2, a1, a2;
const Vector e[3] = { DIR_VEC(1, 0, 0), DIR_VEC(0, 1, 0), DIR_VEC(0, 0, 1) };
for(int i = 0; i < 3; ++i)
for(int j = 0; j < 3; ++j)
{
Vector axis = Cross(e[i], t[j]);
ProjectToAxis(axis, d1, d2);
aabb.ProjectToAxis(axis, a1, a2);
if (d2 <= a1 || d1 >= a2) return false;
}
*/
// eX <cross> t[0]
Scalar d1 = t[0].y() * ac.z() - t[0].z() * ac.y();
Scalar d2 = t[0].y() * cc.z() - t[0].z() * cc.y();
Scalar tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[0].z() + h.z() * at[0].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eX <cross> t[1]
d1 = t[1].y() * ac.z() - t[1].z() * ac.y();
d2 = t[1].y() * bc.z() - t[1].z() * bc.y();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[1].z() + h.z() * at[1].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eX <cross> t[2]
d1 = t[2].y() * ac.z() - t[2].z() * ac.y();
d2 = t[2].y() * bc.z() - t[2].z() * bc.y();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[2].z() + h.z() * at[2].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eY <cross> t[0]
d1 = t[0].z() * ac.x() - t[0].x() * ac.z();
d2 = t[0].z() * cc.x() - t[0].x() * cc.z();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.x() * at[0].z() + h.z() * at[0].x());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eY <cross> t[1]
d1 = t[1].z() * ac.x() - t[1].x() * ac.z();
d2 = t[1].z() * bc.x() - t[1].x() * bc.z();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.x() * at[1].z() + h.z() * at[1].x());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eY <cross> t[2]
d1 = t[2].z() * ac.x() - t[2].x() * ac.z();
d2 = t[2].z() * bc.x() - t[2].x() * bc.z();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.x() * at[2].z() + h.z() * at[2].x());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eZ <cross> t[0]
d1 = t[0].x() * ac.y() - t[0].y() * ac.x();
d2 = t[0].x() * cc.y() - t[0].y() * cc.x();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[0].x() + h.x() * at[0].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eZ <cross> t[1]
d1 = t[1].x() * ac.y() - t[1].y() * ac.x();
d2 = t[1].x() * bc.y() - t[1].y() * bc.x();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[1].x() + h.x() * at[1].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// eZ <cross> t[2]
d1 = t[2].x() * ac.y() - t[2].y() * ac.x();
d2 = t[2].x() * bc.y() - t[2].y() * bc.x();
tc = (d1 + d2) * 0.5f;
r = std::abs(h.y() * at[2].x() + h.x() * at[2].y());
if (r + std::abs(tc - d1) < std::abs(tc))
return false;
// No separating axis exists, the AABB and triangle intersect.
return true;
}
// Ordering of children cubes.
static const std::array<Vec3d, 8> child_centers {
Vec3d(-1, -1, -1), Vec3d( 1, -1, -1), Vec3d(-1, 1, -1), Vec3d( 1, 1, -1),
Vec3d(-1, -1, 1), Vec3d( 1, -1, 1), Vec3d(-1, 1, 1), Vec3d( 1, 1, 1)
};
// Traversal order of octree children cells for three infill directions,
// so that a single line will be discretized in a strictly monotonous order.
static constexpr std::array<std::array<int, 8>, 3> child_traversal_order {
std::array<int, 8>{ 2, 3, 0, 1, 6, 7, 4, 5 },
std::array<int, 8>{ 4, 0, 6, 2, 5, 1, 7, 3 },
std::array<int, 8>{ 1, 5, 0, 4, 3, 7, 2, 6 },
};
struct Cube
{
Vec3d center;
#ifndef NDEBUG
Vec3d center_octree;
#endif // NDEBUG
std::array<Cube*, 8> children {}; // initialized to nullptrs
Cube(const Vec3d &center) : center(center) {}
};
struct CubeProperties
{
double edge_length; // Lenght of edge of a cube
double height; // Height of rotated cube (standing on the corner)
double diagonal_length; // Length of diagonal of a cube a face
double line_z_distance; // Defines maximal distance from a center of a cube on Z axis on which lines will be created
double line_xy_distance;// Defines maximal distance from a center of a cube on X and Y axis on which lines will be created
};
struct Octree
{
// Octree will allocate its Cubes from the pool. The pool only supports deletion of the complete pool,
// perfect for building up our octree.
boost::object_pool<Cube> pool;
Cube* root_cube { nullptr };
Vec3d origin;
std::vector<CubeProperties> cubes_properties;
Octree(const Vec3d &origin, const std::vector<CubeProperties> &cubes_properties)
: root_cube(pool.construct(origin)), origin(origin), cubes_properties(cubes_properties) {}
void insert_triangle(const Vec3d &a, const Vec3d &b, const Vec3d &c, Cube *current_cube, const BoundingBoxf3 &current_bbox, int depth);
};
void OctreeDeleter::operator()(Octree *p) {
delete p;
}
std::pair<double, double> adaptive_fill_line_spacing(const PrintObject &print_object)
{
// Output, spacing for icAdaptiveCubic and icSupportCubic
double adaptive_line_spacing = 0.;
double support_line_spacing = 0.;
enum class Tristate {
Yes,
No,
Maybe
};
struct RegionFillData {
Tristate has_adaptive_infill;
Tristate has_support_infill;
double density;
double extrusion_width;
};
std::vector<RegionFillData> region_fill_data;
region_fill_data.reserve(print_object.print()->regions().size());
bool build_octree = false;
for (const PrintRegion *region : print_object.print()->regions()) {
const PrintRegionConfig &config = region->config();
bool nonempty = config.fill_density > 0;
bool has_adaptive_infill = nonempty && config.fill_pattern == ipAdaptiveCubic;
bool has_support_infill = nonempty && config.fill_pattern == ipSupportCubic;
region_fill_data.push_back(RegionFillData({
has_adaptive_infill ? Tristate::Maybe : Tristate::No,
has_support_infill ? Tristate::Maybe : Tristate::No,
config.fill_density,
config.infill_extrusion_width
}));
build_octree |= has_adaptive_infill || has_support_infill;
}
if (build_octree) {
// Compute the average of above parameters over all layers
for (const Layer *layer : print_object.layers())
for (size_t region_id = 0; region_id < layer->regions().size(); ++ region_id) {
RegionFillData &rd = region_fill_data[region_id];
if (rd.has_adaptive_infill == Tristate::Maybe && ! layer->regions()[region_id]->fill_surfaces.empty())
rd.has_adaptive_infill = Tristate::Yes;
if (rd.has_support_infill == Tristate::Maybe && ! layer->regions()[region_id]->fill_surfaces.empty())
rd.has_support_infill = Tristate::Yes;
}
double adaptive_fill_density = 0.;
double adaptive_infill_extrusion_width = 0.;
int adaptive_cnt = 0;
double support_fill_density = 0.;
double support_infill_extrusion_width = 0.;
int support_cnt = 0;
for (const RegionFillData &rd : region_fill_data) {
if (rd.has_adaptive_infill == Tristate::Yes) {
adaptive_fill_density += rd.density;
adaptive_infill_extrusion_width += rd.extrusion_width;
++ adaptive_cnt;
} else if (rd.has_support_infill == Tristate::Yes) {
support_fill_density += rd.density;
support_infill_extrusion_width += rd.extrusion_width;
++ support_cnt;
}
}
auto to_line_spacing = [](int cnt, double density, double extrusion_width) {
if (cnt) {
density /= double(cnt);
extrusion_width /= double(cnt);
return extrusion_width / ((density / 100.0f) * 0.333333333f);
} else
return 0.;
};
adaptive_line_spacing = to_line_spacing(adaptive_cnt, adaptive_fill_density, adaptive_infill_extrusion_width);
support_line_spacing = to_line_spacing(support_cnt, support_fill_density, support_infill_extrusion_width);
}
return std::make_pair(adaptive_line_spacing, support_line_spacing);
}
// Context used by generate_infill_lines() when recursively traversing an octree in a DDA fashion
// (Digital Differential Analyzer).
struct FillContext
{
// The angles have to agree with child_traversal_order.
static constexpr double direction_angles[3] {
0.,
(2.0 * M_PI) / 3.0,
-(2.0 * M_PI) / 3.0
};
FillContext(const Octree &octree, double z_position, int direction_idx) :
origin_world(octree.origin),
cubes_properties(octree.cubes_properties),
z_position(z_position),
traversal_order(child_traversal_order[direction_idx]),
cos_a(cos(direction_angles[direction_idx])),
sin_a(sin(direction_angles[direction_idx]))
{
static constexpr auto unused = std::numeric_limits<coord_t>::max();
temp_lines.assign((1 << octree.cubes_properties.size()) - 1, Line(Point(unused, unused), Point(unused, unused)));
}
// Rotate the point, uses the same convention as Point::rotate().
Vec2d rotate(const Vec2d& v) { return Vec2d(this->cos_a * v.x() - this->sin_a * v.y(), this->sin_a * v.x() + this->cos_a * v.y()); }
// Center of the root cube in the Octree coordinate system.
const Vec3d origin_world;
const std::vector<CubeProperties> &cubes_properties;
// Top of the current layer.
const double z_position;
// Order of traversal for this line direction.
const std::array<int, 8> traversal_order;
// Rotation of the generated line for this line direction.
const double cos_a;
const double sin_a;
// Linearized tree spanning a single Octree wall, used to connect lines spanning
// neighboring Octree cells. Unused lines have the Line::a::x set to infinity.
std::vector<Line> temp_lines;
// Final output
std::vector<Line> output_lines;
};
static constexpr double octree_rot[3] = { 5.0 * M_PI / 4.0, Geometry::deg2rad(215.264), M_PI / 6.0 };
Eigen::Quaterniond transform_to_world()
{
return Eigen::AngleAxisd(octree_rot[2], Vec3d::UnitZ()) * Eigen::AngleAxisd(octree_rot[1], Vec3d::UnitY()) * Eigen::AngleAxisd(octree_rot[0], Vec3d::UnitX());
}
Eigen::Quaterniond transform_to_octree()
{
return Eigen::AngleAxisd(- octree_rot[0], Vec3d::UnitX()) * Eigen::AngleAxisd(- octree_rot[1], Vec3d::UnitY()) * Eigen::AngleAxisd(- octree_rot[2], Vec3d::UnitZ());
}
#ifndef NDEBUG
// Verify that the traversal order of the octree children matches the line direction,
// therefore the infill line may get extended with O(1) time & space complexity.
static bool verify_traversal_order(
FillContext &context,
const Cube *cube,
int depth,
const Vec2d &line_from,
const Vec2d &line_to)
{
std::array<Vec3d, 8> c;
Eigen::Quaterniond to_world = transform_to_world();
for (int i = 0; i < 8; ++i) {
int j = context.traversal_order[i];
Vec3d cntr = to_world * (cube->center_octree + (child_centers[j] * (context.cubes_properties[depth].edge_length / 4.)));
assert(!cube->children[j] || cube->children[j]->center.isApprox(cntr));
c[i] = cntr;
}
std::array<Vec3d, 10> dirs = {
c[1] - c[0], c[2] - c[0], c[3] - c[1], c[3] - c[2], c[3] - c[0],
c[5] - c[4], c[6] - c[4], c[7] - c[5], c[7] - c[6], c[7] - c[4]
};
assert(std::abs(dirs[4].z()) < 0.001);
assert(std::abs(dirs[9].z()) < 0.001);
assert(dirs[0].isApprox(dirs[3]));
assert(dirs[1].isApprox(dirs[2]));
assert(dirs[5].isApprox(dirs[8]));
assert(dirs[6].isApprox(dirs[7]));
Vec3d line_dir = Vec3d(line_to.x() - line_from.x(), line_to.y() - line_from.y(), 0.).normalized();
for (auto& dir : dirs) {
double d = dir.normalized().dot(line_dir);
assert(d > 0.7);
}
return true;
}
#endif // NDEBUG
static void generate_infill_lines_recursive(
FillContext &context,
const Cube *cube,
// Address of this wall in the octree, used to address context.temp_lines.
int address,
int depth)
{
assert(cube != nullptr);
const std::vector<CubeProperties> &cubes_properties = context.cubes_properties;
const double z_diff = context.z_position - cube->center.z();
const double z_diff_abs = std::abs(z_diff);
if (z_diff_abs > cubes_properties[depth].height / 2.)
return;
if (z_diff_abs < cubes_properties[depth].line_z_distance) {
// Discretize a single wall splitting the cube into two.
const double zdist = cubes_properties[depth].line_z_distance;
Vec2d from(
0.5 * cubes_properties[depth].diagonal_length * (zdist - z_diff_abs) / zdist,
cubes_properties[depth].line_xy_distance - (zdist + z_diff) / sqrt(2.));
Vec2d to(-from.x(), from.y());
from = context.rotate(from);
to = context.rotate(to);
// Relative to cube center
Vec2d offset(cube->center.x() - context.origin_world.x(), cube->center.y() - context.origin_world.y());
from += offset;
to += offset;
// Verify that the traversal order of the octree children matches the line direction,
// therefore the infill line may get extended with O(1) time & space complexity.
assert(verify_traversal_order(context, cube, depth, from, to));
// Either extend an existing line or start a new one.
Line &last_line = context.temp_lines[address];
Line new_line(Point::new_scale(from), Point::new_scale(to));
if (last_line.a.x() == std::numeric_limits<coord_t>::max()) {
last_line.a = new_line.a;
} else if ((new_line.a - last_line.b).cwiseAbs().maxCoeff() > 300) { // SCALED_EPSILON is 100 and it is not enough) {
context.output_lines.emplace_back(last_line);
last_line.a = new_line.a;
}
last_line.b = new_line.b;
}
// left child index
address = address * 2 + 1;
-- depth;
size_t i = 0;
for (const int child_idx : context.traversal_order) {
const Cube *child = cube->children[child_idx];
if (child != nullptr)
generate_infill_lines_recursive(context, child, address, depth);
if (++ i == 4)
// right child index
++ address;
}
}
#if 0
// Collect the line segments.
static Polylines chain_lines(const std::vector<Line> &lines, const double point_distance_epsilon)
{
// Create line end point lookup.
struct LineEnd {
LineEnd(Line *line, bool start) : line(line), start(start) {}
Line *line;
// Is it the start or end point?
bool start;
const Point& point() const { return start ? line->a : line->b; }
const Point& other_point() const { return start ? line->b : line->a; }
LineEnd other_end() const { return LineEnd(line, ! start); }
bool operator==(const LineEnd &rhs) const { return this->line == rhs.line && this->start == rhs.start; }
};
struct LineEndAccessor {
const Point* operator()(const LineEnd &pt) const { return &pt.point(); }
};
typedef ClosestPointInRadiusLookup<LineEnd, LineEndAccessor> ClosestPointLookupType;
ClosestPointLookupType closest_end_point_lookup(point_distance_epsilon);
for (const Line &line : lines) {
closest_end_point_lookup.insert(LineEnd(&line, true));
closest_end_point_lookup.insert(LineEnd(&line, false));
}
// Chain the lines.
std::vector<char> line_consumed(lines.size(), false);
static const double point_distance_epsilon2 = point_distance_epsilon * point_distance_epsilon;
Polylines out;
for (const Line &seed : lines)
if (! line_consumed[&seed - lines.data()]) {
line_consumed[&seed - lines.data()] = true;
closest_end_point_lookup.erase(LineEnd(&seed, false));
closest_end_point_lookup.erase(LineEnd(&seed, true));
Polyline pl { seed.a, seed.b };
for (size_t round = 0; round < 2; ++ round) {
for (;;) {
auto [line_end, dist2] = closest_end_point_lookup.find(pl.last_point());
if (line_end == nullptr || dist2 >= point_distance_epsilon2)
// Cannot extent in this direction.
break;
// Average the last point.
pl.points.back() = 0.5 * (pl.points.back() + line_end->point());
// and extend with the new line segment.
pl.points.emplace_back(line_end->other_point());
closest_end_point_lookup.erase(line_end);
closest_end_point_lookup.erase(line_end->other_end());
line_consumed[line_end->line - lines.data()] = true;
}
// reverse and try the oter direction.
pl.reverse();
}
out.emplace_back(std::move(pl));
}
return out;
}
#endif
#ifndef NDEBUG
// #define ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT
#endif
#ifdef ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT
static void export_infill_lines_to_svg(const ExPolygon &expoly, const Polylines &polylines, const std::string &path)
{
BoundingBox bbox = get_extents(expoly);
bbox.offset(scale_(3.));
::Slic3r::SVG svg(path, bbox);
svg.draw(expoly);
svg.draw_outline(expoly, "green");
svg.draw(polylines, "red");
static constexpr double trim_length = scale_(0.4);
for (Polyline polyline : polylines) {
Vec2d a = polyline.points.front().cast<double>();
Vec2d d = polyline.points.back().cast<double>();
if (polyline.size() == 2) {
Vec2d v = d - a;
double l = v.norm();
if (l > 2. * trim_length) {
a += v * trim_length / l;
d -= v * trim_length / l;
polyline.points.front() = a.cast<coord_t>();
polyline.points.back() = d.cast<coord_t>();
} else
polyline.points.clear();
} else if (polyline.size() > 2) {
Vec2d b = polyline.points[1].cast<double>();
Vec2d c = polyline.points[polyline.points.size() - 2].cast<double>();
Vec2d v = b - a;
double l = v.norm();
if (l > trim_length) {
a += v * trim_length / l;
polyline.points.front() = a.cast<coord_t>();
} else
polyline.points.erase(polyline.points.begin());
v = d - c;
l = v.norm();
if (l > trim_length)
polyline.points.back() = (d - v * trim_length / l).cast<coord_t>();
else
polyline.points.pop_back();
}
svg.draw(polyline, "black");
}
}
#endif /* ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT */
void Filler::_fill_surface_single(
const FillParams & params,
unsigned int thickness_layers,
const std::pair<float, Point> &direction,
ExPolygon &expolygon,
Polylines &polylines_out)
{
assert (this->adapt_fill_octree);
Polylines all_polylines;
{
// 3 contexts for three directions of infill lines
std::array<FillContext, 3> contexts {
FillContext { *adapt_fill_octree, this->z, 0 },
FillContext { *adapt_fill_octree, this->z, 1 },
FillContext { *adapt_fill_octree, this->z, 2 }
};
// Generate the infill lines along the octree cells, merge touching lines of the same direction.
size_t num_lines = 0;
for (auto &context : contexts) {
generate_infill_lines_recursive(context, adapt_fill_octree->root_cube, 0, int(adapt_fill_octree->cubes_properties.size()) - 1);
num_lines += context.output_lines.size() + context.temp_lines.size();
}
// Collect the lines.
std::vector<Line> lines;
lines.reserve(num_lines);
for (auto &context : contexts) {
append(lines, context.output_lines);
for (const Line &line : context.temp_lines)
if (line.a.x() != std::numeric_limits<coord_t>::max())
lines.emplace_back(line);
}
// Convert lines to polylines.
//FIXME chain the lines
all_polylines.reserve(lines.size());
std::transform(lines.begin(), lines.end(), std::back_inserter(all_polylines), [](const Line& l) { return Polyline{ l.a, l.b }; });
}
// Crop all polylines
all_polylines = intersection_pl(std::move(all_polylines), to_polygons(expolygon));
#ifdef ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT
{
static int iRun = 0;
export_infill_lines_to_svg(expolygon, all_polylines, debug_out_path("FillAdaptive-initial-%d.svg", iRun++));
}
#endif /* ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT */
if (params.dont_connect)
append(polylines_out, std::move(all_polylines));
else
connect_infill(chain_polylines(std::move(all_polylines)), expolygon, polylines_out, this->spacing, params);
#ifdef ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT
{
static int iRun = 0;
export_infill_lines_to_svg(expolygon, polylines_out, debug_out_path("FillAdaptive-final-%d.svg", iRun ++));
}
#endif /* ADAPTIVE_CUBIC_INFILL_DEBUG_OUTPUT */
}
static double bbox_max_radius(const BoundingBoxf3 &bbox, const Vec3d &center)
{
const auto p = (bbox.min - center);
const auto s = bbox.size();
double r2max = 0.;
for (int i = 0; i < 8; ++ i)
r2max = std::max(r2max, (p + Vec3d(s.x() * double(i & 1), s.y() * double(i & 2), s.z() * double(i & 4))).squaredNorm());
return sqrt(r2max);
}
static std::vector<CubeProperties> make_cubes_properties(double max_cube_edge_length, double line_spacing)
{
max_cube_edge_length += EPSILON;
std::vector<CubeProperties> cubes_properties;
for (double edge_length = line_spacing * 2.;; edge_length *= 2.)
{
CubeProperties props{};
props.edge_length = edge_length;
props.height = edge_length * sqrt(3);
props.diagonal_length = edge_length * sqrt(2);
props.line_z_distance = edge_length / sqrt(3);
props.line_xy_distance = edge_length / sqrt(6);
cubes_properties.emplace_back(props);
if (edge_length > max_cube_edge_length)
break;
}
return cubes_properties;
}
static inline bool is_overhang_triangle(const Vec3d &a, const Vec3d &b, const Vec3d &c, const Vec3d &up)
{
// Calculate triangle normal.
auto n = (b - a).cross(c - b);
return n.dot(up) > 0.707 * n.norm();
}
static void transform_center(Cube *current_cube, const Eigen::Matrix3d &rot)
{
#ifndef NDEBUG
current_cube->center_octree = current_cube->center;
#endif // NDEBUG
current_cube->center = rot * current_cube->center;
for (auto *child : current_cube->children)
if (child)
transform_center(child, rot);
}
OctreePtr build_octree(const indexed_triangle_set &triangle_mesh, coordf_t line_spacing, bool support_overhangs_only)
{
assert(line_spacing > 0);
assert(! std::isnan(line_spacing));
BoundingBox3Base<Vec3f> bbox(triangle_mesh.vertices);
Vec3d cube_center = bbox.center().cast<double>();
std::vector<CubeProperties> cubes_properties = make_cubes_properties(double(bbox.size().maxCoeff()), line_spacing);
auto octree = OctreePtr(new Octree(cube_center, cubes_properties));
if (cubes_properties.size() > 1) {
auto up_vector = support_overhangs_only ? Vec3d(transform_to_octree() * Vec3d(0., 0., 1.)) : Vec3d();
for (auto &tri : triangle_mesh.indices) {
auto a = triangle_mesh.vertices[tri[0]].cast<double>();
auto b = triangle_mesh.vertices[tri[1]].cast<double>();
auto c = triangle_mesh.vertices[tri[2]].cast<double>();
if (support_overhangs_only && ! is_overhang_triangle(a, b, c, up_vector))
continue;
double edge_length_half = 0.5 * cubes_properties.back().edge_length;
Vec3d diag_half(edge_length_half, edge_length_half, edge_length_half);
octree->insert_triangle(
a, b, c,
octree->root_cube,
BoundingBoxf3(octree->root_cube->center - diag_half, octree->root_cube->center + diag_half),
int(cubes_properties.size()) - 1);
}
{
// Transform the octree to world coordinates to reduce computation when extracting infill lines.
auto rot = transform_to_world().toRotationMatrix();
transform_center(octree->root_cube, rot);
octree->origin = rot * octree->origin;
}
}
return octree;
}
void Octree::insert_triangle(const Vec3d &a, const Vec3d &b, const Vec3d &c, Cube *current_cube, const BoundingBoxf3 &current_bbox, int depth)
{
assert(current_cube);
assert(depth > 0);
for (size_t i = 0; i < 8; ++ i) {
const Vec3d &child_center = child_centers[i];
// Calculate a slightly expanded bounding box of a child cube to cope with triangles touching a cube wall and other numeric errors.
// We will rather densify the octree a bit more than necessary instead of missing a triangle.
BoundingBoxf3 bbox;
for (int k = 0; k < 3; ++ k) {
if (child_center[k] == -1.) {
bbox.min[k] = current_bbox.min[k];
bbox.max[k] = current_cube->center[k] + EPSILON;
} else {
bbox.min[k] = current_cube->center[k] - EPSILON;
bbox.max[k] = current_bbox.max[k];
}
}
if (triangle_AABB_intersects(a, b, c, bbox)) {
if (! current_cube->children[i])
current_cube->children[i] = this->pool.construct(current_cube->center + (child_center * (this->cubes_properties[depth].edge_length / 4)));
if (depth > 1)
this->insert_triangle(a, b, c, current_cube->children[i], bbox, depth - 1);
}
}
}
} // namespace FillAdaptive
} // namespace Slic3r