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Refactor: Allow any number of expansion zones in expand_bridges.

Browse Source 
Split the function expand_bridges_detect_orientations into
multiple functions. And allow any number of expansion zones
by using a vector instead of explicitly listing the
parameters.
This commit is contained in:
Martin Šach 2023-11-22 12:47:38 +01:00 committed by Lukas Matena
parent 9797110a96
commit 81d9724436
3 changed files with 254 additions and 172 deletions
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379
src/libslic3r/LayerRegion.cpp
View File

@ -169,193 +169,259 @@ static ExPolygons fill_surfaces_extract_expolygons(Surfaces &surfaces, std::init
return out;
}
// Extract bridging surfaces from "surfaces", expand them into "shells" using expansion_params,
// detect bridges.
// Trim "shells" by the expanded bridges.
Surfaces expand_bridges_detect_orientations(
Surfaces &surfaces,
ExPolygons &shells,
const Algorithm::RegionExpansionParameters &expansion_params_into_solid_infill,
ExPolygons &sparse,
const Algorithm::RegionExpansionParameters &expansion_params_into_sparse_infill,
const float closing_radius)
{
using namespace Slic3r::Algorithm;
// Cache for detecting bridge orientation and merging regions with overlapping expansions.
struct Bridge {
ExPolygon expolygon;
uint32_t group_id;
std::vector<Algorithm::RegionExpansionEx>::const_iterator bridge_expansion_begin;
std::optional<double> angle{std::nullopt};
};
double thickness;
ExPolygons bridges_ex = fill_surfaces_extract_expolygons(surfaces, {stBottomBridge}, thickness);
if (bridges_ex.empty())
return {};
// Calculate bridge anchors and their expansions in their respective shell region.
WaveSeeds bridge_anchors = wave_seeds(bridges_ex, shells, expansion_params_into_solid_infill.tiny_expansion, true);
std::vector<RegionExpansionEx> bridge_expansions = propagate_waves_ex(bridge_anchors, shells, expansion_params_into_solid_infill);
bool expanded_into_shells = ! bridge_expansions.empty();
bool expanded_into_sparse = false;
{
WaveSeeds bridge_anchors_sparse = wave_seeds(bridges_ex, sparse, expansion_params_into_sparse_infill.tiny_expansion, true);
std::vector<RegionExpansionEx> bridge_expansions_sparse = propagate_waves_ex(bridge_anchors_sparse, sparse, expansion_params_into_sparse_infill);
if (! bridge_expansions_sparse.empty()) {
expanded_into_sparse = true;
for (WaveSeed &seed : bridge_anchors_sparse)
seed.boundary += uint32_t(shells.size());
for (RegionExpansionEx &expansion : bridge_expansions_sparse)
expansion.boundary_id += uint32_t(shells.size());
append(bridge_anchors, std::move(bridge_anchors_sparse));
append(bridge_expansions, std::move(bridge_expansions_sparse));
}
// Group the bridge surfaces by overlaps.
uint32_t group_id(std::vector<Bridge> &bridges, uint32_t src_id) {
uint32_t group_id = bridges[src_id].group_id;
while (group_id != src_id) {
src_id = group_id;
group_id = bridges[src_id].group_id;
}
bridges[src_id].group_id = group_id;
return group_id;
};
// Cache for detecting bridge orientation and merging regions with overlapping expansions.
struct Bridge {
ExPolygon expolygon;
uint32_t group_id;
std::vector<RegionExpansionEx>::const_iterator bridge_expansion_begin;
double angle = -1;
};
std::vector<Bridge> bridges;
std::vector<Bridge> get_grouped_bridges(
ExPolygons&& bridge_expolygons,
const std::vector<Algorithm::RegionExpansionEx>& bridge_expansions
) {
using namespace Algorithm;
std::vector<Bridge> result;
{
bridges.reserve(bridges_ex.size());
result.reserve(bridge_expansions.size());
uint32_t group_id = 0;
for (ExPolygon &ex : bridges_ex)
bridges.push_back({ std::move(ex), group_id ++, bridge_expansions.end() });
bridges_ex.clear();
using std::move_iterator;
for (ExPolygon& expolygon : bridge_expolygons)
result.push_back({ std::move(expolygon), group_id ++, bridge_expansions.end() });
}
// Group the bridge surfaces by overlaps.
auto group_id = [&bridges](uint32_t src_id) {
uint32_t group_id = bridges[src_id].group_id;
while (group_id != src_id) {
src_id = group_id;
group_id = bridges[src_id].group_id;
}
bridges[src_id].group_id = group_id;
return group_id;
};
{
// Detect overlaps of bridge anchors inside their respective shell regions.
// bridge_expansions are sorted by boundary id and source id.
for (auto expansion_iterator = bridge_expansions.begin(); expansion_iterator != bridge_expansions.end();) {
auto boundary_region_begin = expansion_iterator;
auto boundary_region_end = std::find_if(
next(expansion_iterator),
bridge_expansions.end(),
[&](const RegionExpansionEx& expansion){
return expansion.boundary_id != expansion_iterator->boundary_id;
}
);
// Cache of bboxes per expansion boundary.
std::vector<BoundingBox> bboxes;
// Detect overlaps of bridge anchors inside their respective shell regions.
// bridge_expansions are sorted by boundary id and source id.
for (auto it = bridge_expansions.begin(); it != bridge_expansions.end();) {
// For each boundary region:
auto it_begin = it;
auto it_end = std::next(it_begin);
for (; it_end != bridge_expansions.end() && it_end->boundary_id == it_begin->boundary_id; ++ it_end) ;
bboxes.clear();
bboxes.reserve(it_end - it_begin);
for (auto it2 = it_begin; it2 != it_end; ++ it2)
bboxes.emplace_back(get_extents(it2->expolygon.contour));
// For each bridge anchor of the current source:
for (; it != it_end; ++ it) {
// A grup id for this bridge.
for (auto it2 = std::next(it); it2 != it_end; ++ it2)
if (it->src_id != it2->src_id &&
bboxes[it - it_begin].overlap(bboxes[it2 - it_begin]) &&
// One may ignore holes, they are irrelevant for intersection test.
! intersection(it->expolygon.contour, it2->expolygon.contour).empty()) {
// The two bridge regions intersect. Give them the same (lower) group id.
uint32_t id = group_id(it->src_id);
uint32_t id2 = group_id(it2->src_id);
if (id < id2)
bridges[id2].group_id = id;
else
bridges[id].group_id = id2;
}
std::vector<BoundingBox> bounding_boxes;
bounding_boxes.reserve(std::distance(boundary_region_begin, boundary_region_end));
std::transform(
boundary_region_begin,
boundary_region_end,
std::back_inserter(bounding_boxes),
[](const RegionExpansionEx& expansion){
return get_extents(expansion.expolygon.contour);
}
);
// For each bridge anchor of the current source:
for (;expansion_iterator != boundary_region_end; ++expansion_iterator) {
auto candidate_iterator = std::next(expansion_iterator);
for (;candidate_iterator != boundary_region_end; ++candidate_iterator) {
const BoundingBox& current_bounding_box{
bounding_boxes[expansion_iterator - boundary_region_begin]
};
const BoundingBox& candidate_bounding_box{
bounding_boxes[candidate_iterator - boundary_region_begin]
};
if (
expansion_iterator->src_id != candidate_iterator->src_id
&& current_bounding_box.overlap(candidate_bounding_box)
// One may ignore holes, they are irrelevant for intersection test.
&& !intersection(expansion_iterator->expolygon.contour, candidate_iterator->expolygon.contour).empty()
) {
// The two bridge regions intersect. Give them the same (lower) group id.
uint32_t id = group_id(result, expansion_iterator->src_id);
uint32_t id2 = group_id(result, candidate_iterator->src_id);
if (id < id2)
result[id2].group_id = id;
else
result[id].group_id = id2;
}
}
}
}
return result;
}
// Detect bridge directions.
{
std::sort(bridge_anchors.begin(), bridge_anchors.end(), Algorithm::lower_by_src_and_boundary);
auto it_bridge_anchor = bridge_anchors.begin();
Lines lines;
void detect_bridge_directions(
const Algorithm::WaveSeeds& bridge_anchors,
std::vector<Bridge>& bridges,
const std::vector<ExpansionZone>& expansion_zones
) {
if (expansion_zones.empty()) {
throw std::runtime_error("At least one expansion zone must exist!");
}
auto it_bridge_anchor = bridge_anchors.begin();
for (uint32_t bridge_id = 0; bridge_id < uint32_t(bridges.size()); ++ bridge_id) {
Bridge &bridge = bridges[bridge_id];
Polygons anchor_areas;
for (uint32_t bridge_id = 0; bridge_id < uint32_t(bridges.size()); ++ bridge_id) {
Bridge &bridge = bridges[bridge_id];
// lines.clear();
anchor_areas.clear();
int32_t last_anchor_id = -1;
for (; it_bridge_anchor != bridge_anchors.end() && it_bridge_anchor->src == bridge_id; ++ it_bridge_anchor) {
if (last_anchor_id != int(it_bridge_anchor->boundary)) {
last_anchor_id = int(it_bridge_anchor->boundary);
append(anchor_areas, to_polygons(last_anchor_id < int32_t(shells.size()) ? shells[last_anchor_id] : sparse[last_anchor_id - int32_t(shells.size())]));
int32_t last_anchor_id = -1;
for (; it_bridge_anchor != bridge_anchors.end() && it_bridge_anchor->src == bridge_id; ++ it_bridge_anchor) {
if (last_anchor_id != int(it_bridge_anchor->boundary)) {
last_anchor_id = int(it_bridge_anchor->boundary);
unsigned start_index{};
unsigned end_index{};
for (const ExpansionZone& expansion_zone: expansion_zones) {
end_index += expansion_zone.expolygons.size();
if (last_anchor_id < end_index) {
append(anchor_areas, to_polygons(expansion_zone.expolygons[last_anchor_id - start_index]));
break;
}
start_index += expansion_zone.expolygons.size();
}
// if (Points &polyline = it_bridge_anchor->path; polyline.size() >= 2) {
// reserve_more_power_of_2(lines, polyline.size() - 1);
// for (size_t i = 1; i < polyline.size(); ++ i)
// lines.push_back({ polyline[i - 1], polyline[1] });
// }
}
lines = to_lines(diff_pl(to_polylines(bridge.expolygon), expand(anchor_areas, float(SCALED_EPSILON))));
auto [bridging_dir, unsupported_dist] = detect_bridging_direction(lines, to_polygons(bridge.expolygon));
bridge.angle = M_PI + std::atan2(bridging_dir.y(), bridging_dir.x());
#if 0
}
Lines lines{to_lines(diff_pl(to_polylines(bridge.expolygon), expand(anchor_areas, float(SCALED_EPSILON))))};
auto [bridging_dir, unsupported_dist] = detect_bridging_direction(lines, to_polygons(bridge.expolygon));
bridge.angle = M_PI + std::atan2(bridging_dir.y(), bridging_dir.x());
if constexpr (false) {
coordf_t stroke_width = scale_(0.06);
BoundingBox bbox = get_extents(anchor_areas);
bbox.merge(get_extents(bridge.expolygon));
bbox.offset(scale_(1.));
::Slic3r::SVG
svg(debug_out_path(("bridge" + std::to_string(bridge.angle) + "_" /* + std::to_string(this->layer()->bottom_z())*/).c_str()),
svg(debug_out_path(("bridge" + std::to_string(*bridge.angle) + "_" /* + std::to_string(this->layer()->bottom_z())*/).c_str()),
bbox);
svg.draw(bridge.expolygon, "cyan");
svg.draw(lines, "green", stroke_width);
svg.draw(anchor_areas, "red");
#endif
}
}
}
Surfaces merge_bridges(
std::vector<Bridge>& bridges,
const std::vector<Algorithm::RegionExpansionEx>& bridge_expansions,
const float closing_radius
) {
for (auto it = bridge_expansions.begin(); it != bridge_expansions.end(); ) {
bridges[it->src_id].bridge_expansion_begin = it;
uint32_t src_id = it->src_id;
for (++ it; it != bridge_expansions.end() && it->src_id == src_id; ++ it) ;
}
Surfaces result;
for (uint32_t bridge_id = 0; bridge_id < uint32_t(bridges.size()); ++ bridge_id) {
if (group_id(bridges, bridge_id) == bridge_id) {
// Head of the group.
Polygons acc;
for (uint32_t bridge_id2 = bridge_id; bridge_id2 < uint32_t(bridges.size()); ++ bridge_id2)
if (group_id(bridges, bridge_id2) == bridge_id) {
append(acc, to_polygons(std::move(bridges[bridge_id2].expolygon)));
auto it_bridge_expansion = bridges[bridge_id2].bridge_expansion_begin;
assert(it_bridge_expansion == bridge_expansions.end() || it_bridge_expansion->src_id == bridge_id2);
for (; it_bridge_expansion != bridge_expansions.end() && it_bridge_expansion->src_id == bridge_id2; ++ it_bridge_expansion)
append(acc, to_polygons(it_bridge_expansion->expolygon));
}
//FIXME try to be smart and pick the best bridging angle for all?
if (!bridges[bridge_id].angle) {
assert(false && "Bridge angle must be pre-calculated!");
}
Surface templ{ stBottomBridge, {} };
templ.bridge_angle = bridges[bridge_id].angle ? *bridges[bridge_id].angle : -1;
//NOTE: The current regularization of the shells can create small unasigned regions in the object (E.G. benchy)
// without the following closing operation, those regions will stay unfilled and cause small holes in the expanded surface.
// look for narrow_ensure_vertical_wall_thickness_region_radius filter.
ExPolygons final = closing_ex(acc, closing_radius);
// without safety offset, artifacts are generated (GH #2494)
// union_safety_offset_ex(acc)
for (ExPolygon &ex : final)
result.emplace_back(templ, std::move(ex));
}
}
return result;
}
// Extract bridging surfaces from "surfaces", expand them into "shells" using expansion_params,
// detect bridges.
// Trim "shells" by the expanded bridges.
Surfaces expand_bridges_detect_orientations(
Surfaces &surfaces,
std::vector<ExpansionZone>& expansion_zones,
const float closing_radius
)
{
using namespace Slic3r::Algorithm;
double thickness;
ExPolygons bridge_expolygons = fill_surfaces_extract_expolygons(surfaces, {stBottomBridge}, thickness);
if (bridge_expolygons.empty())
return {};
// Calculate bridge anchors and their expansions in their respective shell region.
WaveSeeds bridge_anchors;
std::vector<RegionExpansionEx> bridge_expansions;
unsigned processed_bridges_count = 0;
for (ExpansionZone& expansion_zone : expansion_zones) {
WaveSeeds seeds{wave_seeds(
bridge_expolygons,
expansion_zone.expolygons,
expansion_zone.parameters.tiny_expansion,
true
)};
std::vector<RegionExpansionEx> expansions{propagate_waves_ex(
seeds,
expansion_zone.expolygons,
expansion_zone.parameters
)};
for (WaveSeed &seed : seeds)
seed.boundary += processed_bridges_count;
for (RegionExpansionEx &expansion : expansions)
expansion.boundary_id += processed_bridges_count;
expansion_zone.expanded_into = ! expansions.empty();
append(bridge_anchors, std::move(seeds));
append(bridge_expansions, std::move(expansions));
processed_bridges_count += expansion_zone.expolygons.size();
}
std::vector<Bridge> bridges{get_grouped_bridges(
std::move(bridge_expolygons),
bridge_expansions
)};
bridge_expolygons.clear();
std::sort(bridge_anchors.begin(), bridge_anchors.end(), Algorithm::lower_by_src_and_boundary);
detect_bridge_directions(bridge_anchors, bridges, expansion_zones);
// Merge the groups with the same group id, produce surfaces by merging source overhangs with their newly expanded anchors.
Surfaces out;
{
Polygons acc;
Surface templ{ stBottomBridge, {} };
std::sort(bridge_expansions.begin(), bridge_expansions.end(), [](auto &l, auto &r) {
return l.src_id < r.src_id || (l.src_id == r.src_id && l.boundary_id < r.boundary_id);
});
for (auto it = bridge_expansions.begin(); it != bridge_expansions.end(); ) {
bridges[it->src_id].bridge_expansion_begin = it;
uint32_t src_id = it->src_id;
for (++ it; it != bridge_expansions.end() && it->src_id == src_id; ++ it) ;
}
for (uint32_t bridge_id = 0; bridge_id < uint32_t(bridges.size()); ++ bridge_id)
if (group_id(bridge_id) == bridge_id) {
// Head of the group.
acc.clear();
for (uint32_t bridge_id2 = bridge_id; bridge_id2 < uint32_t(bridges.size()); ++ bridge_id2)
if (group_id(bridge_id2) == bridge_id) {
append(acc, to_polygons(std::move(bridges[bridge_id2].expolygon)));
auto it_bridge_expansion = bridges[bridge_id2].bridge_expansion_begin;
assert(it_bridge_expansion == bridge_expansions.end() || it_bridge_expansion->src_id == bridge_id2);
for (; it_bridge_expansion != bridge_expansions.end() && it_bridge_expansion->src_id == bridge_id2; ++ it_bridge_expansion)
append(acc, to_polygons(std::move(it_bridge_expansion->expolygon)));
}
//FIXME try to be smart and pick the best bridging angle for all?
templ.bridge_angle = bridges[bridge_id].angle;
//NOTE: The current regularization of the shells can create small unasigned regions in the object (E.G. benchy)
// without the following closing operation, those regions will stay unfilled and cause small holes in the expanded surface.
// look for narrow_ensure_vertical_wall_thickness_region_radius filter.
ExPolygons final = closing_ex(acc, closing_radius);
// without safety offset, artifacts are generated (GH #2494)
// union_safety_offset_ex(acc)
for (ExPolygon &ex : final)
out.emplace_back(templ, std::move(ex));
}
}
std::sort(bridge_expansions.begin(), bridge_expansions.end(), [](auto &l, auto &r) {
return l.src_id < r.src_id || (l.src_id == r.src_id && l.boundary_id < r.boundary_id);
});
Surfaces out{merge_bridges(bridges, bridge_expansions, closing_radius)};
// Clip by the expanded bridges.
if (expanded_into_shells)
shells = diff_ex(shells, out);
if (expanded_into_sparse)
sparse = diff_ex(sparse, out);
for (ExpansionZone& expansion_zone : expansion_zones)
if (expansion_zone.expanded_into)
expansion_zone.expolygons = diff_ex(expansion_zone.expolygons, out);
return out;
}
// Extract bridging surfaces from "surfaces", expand them into "shells" using expansion_params.
// Trim "shells" by the expanded bridges.
static Surfaces expand_merge_surfaces(
Surfaces expand_merge_surfaces(
Surfaces &surfaces,
SurfaceType surface_type,
ExPolygons &shells,
@ -443,16 +509,21 @@ void LayerRegion::process_external_surfaces(const Layer *lower_layer, const Poly
double layer_thickness;
ExPolygons shells = union_ex(fill_surfaces_extract_expolygons(m_fill_surfaces.surfaces, { stInternalSolid }, layer_thickness));
ExPolygons sparse = union_ex(fill_surfaces_extract_expolygons(m_fill_surfaces.surfaces, { stInternal }, layer_thickness));
const auto expansion_params_into_sparse_infill = RegionExpansionParameters::build(expansion_min, expansion_step, max_nr_expansion_steps);
const auto expansion_params_into_solid_infill = RegionExpansionParameters::build(expansion_bottom_bridge, expansion_step, max_nr_expansion_steps);
std::vector<ExpansionZone> expansion_zones{
ExpansionZone{std::move(shells), expansion_params_into_solid_infill},
ExpansionZone{std::move(sparse), expansion_params_into_sparse_infill},
};
SurfaceCollection bridges;
const auto expansion_params_into_sparse_infill = RegionExpansionParameters::build(expansion_min, expansion_step, max_nr_expansion_steps);
{
BOOST_LOG_TRIVIAL(trace) << "Processing external surface, detecting bridges. layer" << this->layer()->print_z;
const double custom_angle = this->region().config().bridge_angle.value;
const auto expansion_params_into_solid_infill = RegionExpansionParameters::build(expansion_bottom_bridge, expansion_step, max_nr_expansion_steps);
bridges.surfaces = custom_angle > 0 ?
expand_merge_surfaces(m_fill_surfaces.surfaces, stBottomBridge, shells, expansion_params_into_solid_infill, sparse, expansion_params_into_sparse_infill, closing_radius, Geometry::deg2rad(custom_angle)) :
expand_bridges_detect_orientations(m_fill_surfaces.surfaces, shells, expansion_params_into_solid_infill, sparse, expansion_params_into_sparse_infill, closing_radius);
expand_bridges_detect_orientations(m_fill_surfaces.surfaces, expansion_zones, closing_radius);
BOOST_LOG_TRIVIAL(trace) << "Processing external surface, detecting bridges - done";
#if 0
{

15
src/libslic3r/LayerRegion.hpp
View File

@ -156,18 +156,21 @@ private:
// Polygons bridged;
};
struct ExpansionZone {
ExPolygons expolygons;
Algorithm::RegionExpansionParameters parameters;
bool expanded_into = false;
};
/**
* Extract bridging surfaces from "surfaces", expand them into "shells" using expansion_params,
* detect bridges.
* Trim "shells" by the expanded bridges.
*/
Surfaces expand_bridges_detect_orientations(
Surfaces &surfaces,
ExPolygons &shells,
const Algorithm::RegionExpansionParameters &expansion_params_into_solid_infill,
ExPolygons &sparse,
const Algorithm::RegionExpansionParameters &expansion_params_into_sparse_infill,
const float closing_radius
Surfaces &surfaces,
std::vector<ExpansionZone>& expansion_zones,
const float closing_radius
);
}

32
tests/libslic3r/test_layer_region.cpp
View File

@ -6,7 +6,7 @@
using namespace Slic3r;
constexpr bool export_svgs = false;
constexpr bool export_svgs = true;
ExPolygon rectangle(const Point& origin, const int width, const int height) {
return {
@ -44,7 +44,6 @@ TEST_CASE("test the bridge expansion with the bridge angle detection", "[LayerRe
const float scaled_spacing{scaled(0.3)};
static constexpr const float expansion_step = scaled<float>(0.1);
// Don't take more than max_nr_steps for small expansion_step.
static constexpr const size_t max_nr_expansion_steps = 5;
const float closing_radius = 0.55f * 0.65f * 1.05f * scaled_spacing;
const int shells_expansion_depth = scaled(0.6);
@ -60,12 +59,21 @@ TEST_CASE("test the bridge expansion with the bridge angle detection", "[LayerRe
max_nr_expansion_steps
);
std::vector<ExpansionZone> expansion_zones{
ExpansionZone{
std::move(shells),
expansion_params_into_solid_infill,
},
ExpansionZone{
std::move(sparse),
expansion_params_into_sparse_infill,
}
};
Surfaces result{expand_bridges_detect_orientations(
surfaces,
shells,
expansion_params_into_solid_infill,
sparse,
expansion_params_into_sparse_infill, closing_radius
expansion_zones,
closing_radius
)};
if constexpr (export_svgs) {
@ -75,8 +83,8 @@ TEST_CASE("test the bridge expansion with the bridge angle detection", "[LayerRe
});
svg.draw(surfaces, "blue");
svg.draw(shells, "green");
svg.draw(sparse, "red");
svg.draw(expansion_zones[0].expolygons, "green");
svg.draw(expansion_zones[1].expolygons, "red");
svg.draw_outline(result, "black", "", scale_(0.01));
}
@ -91,8 +99,8 @@ TEST_CASE("test the bridge expansion with the bridge angle detection", "[LayerRe
CHECK(result.at(1).expolygon.contour.lines().at(7).length() == sparse_expansion_depth);
CHECK(result.at(1).expolygon.contour.lines().at(11).length() == sparse_expansion_depth);
CHECK(intersection_ex({result.at(0).expolygon}, sparse).size() == 0);
CHECK(intersection_ex({result.at(0).expolygon}, shells).size() == 0);
CHECK(intersection_ex({result.at(1).expolygon}, sparse).size() == 0);
CHECK(intersection_ex({result.at(1).expolygon}, shells).size() == 0);
CHECK(intersection_ex({result.at(0).expolygon}, expansion_zones[0].expolygons).size() == 0);
CHECK(intersection_ex({result.at(0).expolygon}, expansion_zones[1].expolygons).size() == 0);
CHECK(intersection_ex({result.at(1).expolygon}, expansion_zones[0].expolygons).size() == 0);
CHECK(intersection_ex({result.at(1).expolygon}, expansion_zones[1].expolygons).size() == 0);
}