3DPrinting/PrusaSlicer-NonPlainar
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Improved robustness of slicing when the slicing plane

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crosses a horizontal plane of an object exactly.
Should improve Github issues #831, #895, #1102
This commit is contained in:
bubnikv 2018-08-08 16:24:10 +02:00
parent 93b8f3147c
commit 00e9f07a03
5 changed files with 188 additions and 86 deletions
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4
xs/src/libslic3r/Fill/FillHoneycomb.cpp
View file

@ -86,8 +86,8 @@ void FillHoneycomb::_fill_surface_single(
Polylines paths;
{
Polylines p;
for (Polygons::iterator it = polygons.begin(); it != polygons.end(); ++ it)
p.push_back((Polyline)(*it));
for (Polygon &poly : polygons)
p.emplace_back(poly.points);
paths = intersection_pl(p, to_polygons(expolygon));
}

1
xs/src/libslic3r/Model.cpp
View file

@ -613,6 +613,7 @@ const BoundingBoxf3& ModelObject::bounding_box() const
BoundingBoxf3 raw_bbox;
for (const ModelVolume *v : this->volumes)
if (! v->modifier)
// mesh.bounding_box() returns a cached value.
raw_bbox.merge(v->mesh.bounding_box());
BoundingBoxf3 bb;
for (const ModelInstance *i : this->instances)

2
xs/src/libslic3r/Polyline.hpp
View file

@ -19,6 +19,8 @@ public:
Polyline() {};
Polyline(const Polyline &other) : MultiPoint(other.points) {}
Polyline(Polyline &&other) : MultiPoint(std::move(other.points)) {}
explicit Polyline(const Points &points) : MultiPoint(points) {}
explicit Polyline(Points &&points) : MultiPoint(std::move(points)) {}
Polyline& operator=(const Polyline &other) { points = other.points; return *this; }
Polyline& operator=(Polyline &&other) { points = std::move(other.points); return *this; }
static Polyline new_scale(std::vector<Pointf> points) {

240
xs/src/libslic3r/TriangleMesh.cpp
View file

@ -696,8 +696,7 @@ TriangleMeshSlicer::TriangleMeshSlicer(TriangleMesh* _mesh) :
}
}
void
TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<Polygons>* layers) const
void TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<Polygons>* layers) const
{
BOOST_LOG_TRIVIAL(debug) << "TriangleMeshSlicer::slice";
@ -800,35 +799,37 @@ void TriangleMeshSlicer::_slice_do(size_t facet_idx, std::vector<IntersectionLin
for (std::vector<float>::const_iterator it = min_layer; it != max_layer + 1; ++it) {
std::vector<float>::size_type layer_idx = it - z.begin();
IntersectionLine il;
if (this->slice_facet(*it / SCALING_FACTOR, facet, facet_idx, min_z, max_z, &il)) {
if (this->slice_facet(*it / SCALING_FACTOR, facet, facet_idx, min_z, max_z, &il) == TriangleMeshSlicer::Slicing) {
boost::lock_guard<boost::mutex> l(*lines_mutex);
if (il.edge_type == feHorizontal) {
// Insert all three edges of the face.
const int *vertices = this->mesh->stl.v_indices[facet_idx].vertex;
const bool reverse = this->mesh->stl.facet_start[facet_idx].normal.z < 0;
for (int j = 0; j < 3; ++ j) {
int a_id = vertices[j % 3];
int b_id = vertices[(j+1) % 3];
if (reverse)
std::swap(a_id, b_id);
const stl_vertex *a = &this->v_scaled_shared[a_id];
const stl_vertex *b = &this->v_scaled_shared[b_id];
il.a.x = a->x;
il.a.y = a->y;
il.b.x = b->x;
il.b.y = b->y;
il.a_id = a_id;
il.b_id = b_id;
(*lines)[layer_idx].push_back(il);
}
// Insert all marked edges of the face. The marked edges do not share an edge with another horizontal face
// (they may not have a nighbor, or their neighbor is vertical)
const int *vertices = this->mesh->stl.v_indices[facet_idx].vertex;
const bool reverse = this->mesh->stl.facet_start[facet_idx].normal.z < 0;
uint32_t edge_mask = IntersectionLine::EDGE0;
for (int j = 0; j < 3; ++ j, edge_mask <<= 1)
if (il.flags & edge_mask) {
int a_id = vertices[j % 3];
int b_id = vertices[(j+1) % 3];
if (reverse)
std::swap(a_id, b_id);
const stl_vertex *a = &this->v_scaled_shared[a_id];
const stl_vertex *b = &this->v_scaled_shared[b_id];
il.a.x = a->x;
il.a.y = a->y;
il.b.x = b->x;
il.b.y = b->y;
il.a_id = a_id;
il.b_id = b_id;
(*lines)[layer_idx].emplace_back(il);
}
} else
(*lines)[layer_idx].push_back(il);
(*lines)[layer_idx].emplace_back(il);
}
}
}
void
TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<ExPolygons>* layers) const
void TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<ExPolygons>* layers) const
{
std::vector<Polygons> layers_p;
this->slice(z, &layers_p);
@ -848,8 +849,18 @@ TriangleMeshSlicer::slice(const std::vector<float> &z, std::vector<ExPolygons>*
BOOST_LOG_TRIVIAL(debug) << "TriangleMeshSlicer::make_expolygons in parallel - end";
}
static inline float cross_product(const stl_vertex *a, const stl_vertex *b, const stl_vertex *c)
{
float v1_x = b->x - a->x;
float v1_y = b->y - a->y;
float v2_x = c->x - a->x;
float v2_y = c->y - a->y;
float dir = (b->x - a->x) * (c->y - a->y) - (b->y - a->y) * (c->x - a->x);
return dir;
}
// Return true, if the facet has been sliced and line_out has been filled.
bool TriangleMeshSlicer::slice_facet(
TriangleMeshSlicer::FacetSliceType TriangleMeshSlicer::slice_facet(
float slice_z, const stl_facet &facet, const int facet_idx,
const float min_z, const float max_z,
IntersectionLine *line_out) const
@ -877,22 +888,61 @@ bool TriangleMeshSlicer::slice_facet(
const stl_vertex &v0 = this->v_scaled_shared[vertices[0]];
const stl_vertex &v1 = this->v_scaled_shared[vertices[1]];
const stl_vertex &v2 = this->v_scaled_shared[vertices[2]];
// We may ignore this edge for slicing purposes, but we may still use it for object cutting.
FacetSliceType result = Slicing;
const stl_neighbors &nbr = this->mesh->stl.neighbors_start[facet_idx];
if (min_z == max_z) {
// All three vertices are aligned with slice_z.
line_out->edge_type = feHorizontal;
// Mark neighbor edges, which do not have a neighbor.
uint32_t edges = 0;
uint32_t mask = IntersectionLine::EDGE0;
for (int nbr_idx = 2; nbr_idx != 5; ++ nbr_idx, mask <<= 1)
// If the neighbor with an edge starting with a vertex idx (nbr_idx - 2) shares no
// opposite face, add it to the edges to process when slicing.
if (nbr.neighbor[nbr_idx % 3] == -1)
// Mark this edge.
edges |= mask;
// Use some edges of this triangle for slicing only if at least one of its edge does not have an opposite face.
result = (edges == 0) ? Cutting : Slicing;
line_out->flags |= edges;
if (this->mesh->stl.facet_start[facet_idx].normal.z < 0) {
// If normal points downwards this is a bottom horizontal facet so we reverse its point order.
std::swap(a, b);
std::swap(a_id, b_id);
}
} else if (v0.z < slice_z || v1.z < slice_z || v2.z < slice_z) {
// Two vertices are aligned with the cutting plane, the third vertex is below the cutting plane.
line_out->edge_type = feTop;
std::swap(a, b);
std::swap(a_id, b_id);
} else {
// Two vertices are aligned with the cutting plane, the third vertex is above the cutting plane.
line_out->edge_type = feBottom;
// Two vertices are aligned with the cutting plane, the third vertex is below or above the cutting plane.
int nbr_idx = (j + 2) % 3;
int nbr_face = nbr.neighbor[nbr_idx];
// Is the third vertex below the cutting plane?
bool third_below = v0.z < slice_z || v1.z < slice_z || v2.z < slice_z;
// Is this a concave corner?
if (nbr_face == -1) {
#ifdef _DEBUG
printf("Face has no neighbor!\n");
#endif
} else {
int idx_vertex_opposite = this->mesh->stl.v_indices[nbr_face].vertex[nbr.which_vertex_not[nbr_idx]];
const stl_vertex *c = &this->v_scaled_shared[idx_vertex_opposite];
if (c->z > slice_z) {
// If an edge resides on a cutting plane, and none of the two triangles are coplanar with the cutting plane,
// igore the lower triangle.
if (third_below)
result = Cutting;
} else if (c->z == slice_z) {
// A vertical face shares edge with a horizontal face. Verify, whether the shared corner is convex or concave.
float dir = cross_product(a, b, c);
if (third_below ? (dir < 0.) : (dir > 0.))
result = Cutting;
}
}
if (third_below) {
line_out->edge_type = feTop;
std::swap(a, b);
std::swap(a_id, b_id);
} else
line_out->edge_type = feBottom;
}
line_out->a.x = a->x;
line_out->a.y = a->y;
@ -900,7 +950,7 @@ bool TriangleMeshSlicer::slice_facet(
line_out->b.y = b->y;
line_out->a_id = a_id;
line_out->b_id = b_id;
return true;
return result;
}
if (a->z == slice_z) {
@ -935,7 +985,7 @@ bool TriangleMeshSlicer::slice_facet(
assert(num_points == 2 || num_points == 3);
if (num_points < 3)
// This triangle touches the cutting plane with a single vertex. Ignore it.
return false;
return NoSlice;
// Erase one of the duplicate points.
-- num_points;
for (int i = points_on_layer[1]; i < num_points; ++ i)
@ -945,52 +995,86 @@ bool TriangleMeshSlicer::slice_facet(
// Facets must intersect each plane 0 or 2 times.
assert(num_points == 0 || num_points == 2);
if (num_points == 2) {
line_out->edge_type = feNone;
line_out->edge_type = feGeneral;
line_out->a = (Point)points[1];
line_out->b = (Point)points[0];
line_out->a_id = points[1].point_id;
line_out->b_id = points[0].point_id;
line_out->edge_a_id = points[1].edge_id;
line_out->edge_b_id = points[0].edge_id;
return true;
// General slicing position, use the segment for both slicing and object cutting.
return Slicing;
}
return NoSlice;
}
//FIXME Should this go away? For valid meshes the function slice_facet() returns Slicing
// and sets edges of vertical triangles to produce only a single edge per pair of neighbor faces.
// So the following code makes only sense now to handle degenerate meshes with more than two faces
// sharing a single edge.
static inline void remove_tangent_edges(std::vector<IntersectionLine> &lines)
{
std::vector<IntersectionLine*> by_vertex_pair;
by_vertex_pair.reserve(lines.size());
for (IntersectionLine& line : lines)
if (line.edge_type != feGeneral && line.a_id != -1)
// This is a face edge. Check whether there is its neighbor stored in lines.
by_vertex_pair.emplace_back(&line);
auto edges_lower_sorted = [](const IntersectionLine *l1, const IntersectionLine *l2) {
// Sort vertices of l1, l2 lexicographically
int l1a = l1->a_id;
int l1b = l1->b_id;
int l2a = l2->a_id;
int l2b = l2->b_id;
if (l1a > l1b)
std::swap(l1a, l1b);
if (l2a > l2b)
std::swap(l2a, l2b);
// Lexicographical "lower" operator on lexicographically sorted vertices should bring equal edges together when sored.
return l1a < l2a || (l1a == l2a && l1b < l2b);
};
std::sort(by_vertex_pair.begin(), by_vertex_pair.end(), edges_lower_sorted);
for (auto line = by_vertex_pair.begin(); line != by_vertex_pair.end(); ++ line) {
IntersectionLine &l1 = **line;
if (! l1.skip()) {
// Iterate as long as line and line2 edges share the same end points.
for (auto line2 = line + 1; line2 != by_vertex_pair.end() && ! edges_lower_sorted(*line, *line2); ++ line2) {
// Lines must share the end points.
assert(! edges_lower_sorted(*line, *line2));
assert(! edges_lower_sorted(*line2, *line));
IntersectionLine &l2 = **line2;
if (l2.skip())
continue;
if (l1.a_id == l2.a_id) {
assert(l1.b_id == l2.b_id);
l2.set_skip();
// If they are both oriented upwards or downwards (like a 'V'),
// then we can remove both edges from this layer since it won't
// affect the sliced shape.
// If one of them is oriented upwards and the other is oriented
// downwards, let's only keep one of them (it doesn't matter which
// one since all 'top' lines were reversed at slicing).
if (l1.edge_type == l2.edge_type) {
l1.set_skip();
break;
}
} else {
assert(l1.a_id == l2.b_id && l1.b_id == l2.a_id);
// If this edge joins two horizontal facets, remove both of them.
if (l1.edge_type == feHorizontal && l2.edge_type == feHorizontal) {
l1.set_skip();
l2.set_skip();
break;
}
}
}
}
}
return false;
}
void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygons* loops) const
{
// Remove tangent edges.
//FIXME This is O(n^2) in rare cases when many faces intersect the cutting plane.
for (IntersectionLines::iterator line = lines.begin(); line != lines.end(); ++ line)
if (! line->skip && line->edge_type != feNone) {
// This line is af facet edge. There may be a duplicate line with the same end vertices.
// If the line is is an edge connecting two facets, find another facet edge
// having the same endpoints but in reverse order.
for (IntersectionLines::iterator line2 = line + 1; line2 != lines.end(); ++ line2)
if (! line2->skip && line2->edge_type != feNone) {
// Are these facets adjacent? (sharing a common edge on this layer)
if (line->a_id == line2->a_id && line->b_id == line2->b_id) {
line2->skip = true;
/* if they are both oriented upwards or downwards (like a 'V')
then we can remove both edges from this layer since it won't
affect the sliced shape */
/* if one of them is oriented upwards and the other is oriented
downwards, let's only keep one of them (it doesn't matter which
one since all 'top' lines were reversed at slicing) */
if (line->edge_type == line2->edge_type) {
line->skip = true;
break;
}
} else if (line->a_id == line2->b_id && line->b_id == line2->a_id) {
/* if this edge joins two horizontal facets, remove both of them */
if (line->edge_type == feHorizontal && line2->edge_type == feHorizontal) {
line->skip = true;
line2->skip = true;
break;
}
}
}
}
remove_tangent_edges(lines);
struct OpenPolyline {
OpenPolyline() {};
@ -1013,7 +1097,7 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
by_edge_a_id.reserve(lines.size());
by_a_id.reserve(lines.size());
for (IntersectionLine &line : lines) {
if (! line.skip) {
if (! line.skip()) {
if (line.edge_a_id != -1)
by_edge_a_id.emplace_back(&line);
if (line.a_id != -1)
@ -1030,13 +1114,13 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
// take first spare line and start a new loop
IntersectionLine *first_line = nullptr;
for (; it_line_seed != lines.end(); ++ it_line_seed)
if (! it_line_seed->skip) {
if (! it_line_seed->skip()) {
first_line = &(*it_line_seed ++);
break;
}
if (first_line == nullptr)
break;
first_line->skip = true;
first_line->set_skip();
Points loop_pts;
loop_pts.emplace_back(first_line->a);
IntersectionLine *last_line = first_line;
@ -1057,7 +1141,7 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
if (it_begin != by_edge_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_edge_a_id.end(), &key, by_edge_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip) {
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
@ -1069,7 +1153,7 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
if (it_begin != by_a_id.end()) {
auto it_end = std::upper_bound(it_begin, by_a_id.end(), &key, by_vertex_lower);
for (auto it_line = it_begin; it_line != it_end; ++ it_line)
if (! (*it_line)->skip) {
if (! (*it_line)->skip()) {
next_line = *it_line;
break;
}
@ -1100,7 +1184,7 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
*/
loop_pts.emplace_back(next_line->a);
last_line = next_line;
next_line->skip = true;
next_line->set_skip();
}
}
}
@ -1192,8 +1276,8 @@ void TriangleMeshSlicer::make_loops(std::vector<IntersectionLine> &lines, Polygo
if ((ip1.edge_id != -1 && ip1.edge_id == ip2.edge_id) ||
(ip1.point_id != -1 && ip1.point_id == ip2.point_id)) {
// The current loop is complete. Add it to the output.
assert(opl.points.front().point_id == opl.points.back().point_id);
assert(opl.points.front().edge_id == opl.points.back().edge_id);
//assert(opl.points.front().point_id == opl.points.back().point_id);
//assert(opl.points.front().edge_id == opl.points.back().edge_id);
// Remove the duplicate last point.
opl.points.pop_back();
if (opl.points.size() >= 3) {
@ -1393,7 +1477,7 @@ void TriangleMeshSlicer::cut(float z, TriangleMesh* upper, TriangleMesh* lower)
// intersect facet with cutting plane
IntersectionLine line;
if (this->slice_facet(scaled_z, *facet, facet_idx, min_z, max_z, &line)) {
if (this->slice_facet(scaled_z, *facet, facet_idx, min_z, max_z, &line) != TriangleMeshSlicer::NoSlice) {
// Save intersection lines for generating correct triangulations.
if (line.edge_type == feTop) {
lower_lines.push_back(line);

27
xs/src/libslic3r/TriangleMesh.hpp
View file

@ -76,7 +76,7 @@ private:
enum FacetEdgeType {
// A general case, the cutting plane intersect a face at two different edges.
feNone,
feGeneral,
// Two vertices are aligned with the cutting plane, the third vertex is below the cutting plane.
feTop,
// Two vertices are aligned with the cutting plane, the third vertex is above the cutting plane.
@ -110,6 +110,11 @@ public:
class IntersectionLine : public Line
{
public:
IntersectionLine() : a_id(-1), b_id(-1), edge_a_id(-1), edge_b_id(-1), edge_type(feGeneral), flags(0) {}
bool skip() const { return (this->flags & SKIP) != 0; }
void set_skip() { this->flags |= SKIP; }
// Inherits Point a, b
// For each line end point, either {a,b}_id or {a,b}edge_a_id is set, the other is left to -1.
// Vertex indices of the line end points.
@ -118,11 +123,16 @@ public:
// Source mesh edges of the line end points.
int edge_a_id;
int edge_b_id;
// feNone, feTop, feBottom, feHorizontal
// feGeneral, feTop, feBottom, feHorizontal
FacetEdgeType edge_type;
// Used by TriangleMeshSlicer::make_loops() to skip duplicate edges.
bool skip;
IntersectionLine() : a_id(-1), b_id(-1), edge_a_id(-1), edge_b_id(-1), edge_type(feNone), skip(false) {};
// Used by TriangleMeshSlicer::slice() to skip duplicate edges.
enum {
EDGE0 = 1,
EDGE1 = 2,
EDGE2 = 4,
SKIP = 8,
};
uint32_t flags;
};
typedef std::vector<IntersectionLine> IntersectionLines;
typedef std::vector<IntersectionLine*> IntersectionLinePtrs;
@ -133,7 +143,12 @@ public:
TriangleMeshSlicer(TriangleMesh* _mesh);
void slice(const std::vector<float> &z, std::vector<Polygons>* layers) const;
void slice(const std::vector<float> &z, std::vector<ExPolygons>* layers) const;
bool slice_facet(float slice_z, const stl_facet &facet, const int facet_idx,
enum FacetSliceType {
NoSlice = 0,
Slicing = 1,
Cutting = 2
};
FacetSliceType slice_facet(float slice_z, const stl_facet &facet, const int facet_idx,
const float min_z, const float max_z, IntersectionLine *line_out) const;
void cut(float z, TriangleMesh* upper, TriangleMesh* lower) const;