Files
OrcaSlicer/src/libslic3r/SLA/SupportTreeBuilder.cpp
tamasmeszaros 2ff04e6f68 Bugfixes for support generator
* Fix support heads floating in air
* Fix failing tests for the bridge mesh intersection
* Fix failing assertions
WIP refactoring support tree gen, as its a mess.
2020-08-03 19:05:30 +02:00

566 lines
18 KiB
C++

#include <libslic3r/SLA/SupportTreeBuilder.hpp>
#include <libslic3r/SLA/SupportTreeBuildsteps.hpp>
#include <libslic3r/SLA/Contour3D.hpp>
namespace Slic3r {
namespace sla {
Contour3D sphere(double rho, Portion portion, double fa) {
Contour3D ret;
// prohibit close to zero radius
if(rho <= 1e-6 && rho >= -1e-6) return ret;
auto& vertices = ret.points;
auto& facets = ret.faces3;
// Algorithm:
// Add points one-by-one to the sphere grid and form facets using relative
// coordinates. Sphere is composed effectively of a mesh of stacked circles.
// adjust via rounding to get an even multiple for any provided angle.
double angle = (2*PI / floor(2*PI / fa));
// Ring to be scaled to generate the steps of the sphere
std::vector<double> ring;
for (double i = 0; i < 2*PI; i+=angle) ring.emplace_back(i);
const auto sbegin = size_t(2*std::get<0>(portion)/angle);
const auto send = size_t(2*std::get<1>(portion)/angle);
const size_t steps = ring.size();
const double increment = 1.0 / double(steps);
// special case: first ring connects to 0,0,0
// insert and form facets.
if(sbegin == 0)
vertices.emplace_back(Vec3d(0.0, 0.0, -rho + increment*sbegin*2.0*rho));
auto id = coord_t(vertices.size());
for (size_t i = 0; i < ring.size(); i++) {
// Fixed scaling
const double z = -rho + increment*rho*2.0 * (sbegin + 1.0);
// radius of the circle for this step.
const double r = std::sqrt(std::abs(rho*rho - z*z));
Vec2d b = Eigen::Rotation2Dd(ring[i]) * Eigen::Vector2d(0, r);
vertices.emplace_back(Vec3d(b(0), b(1), z));
if (sbegin == 0)
(i == 0) ? facets.emplace_back(coord_t(ring.size()), 0, 1) :
facets.emplace_back(id - 1, 0, id);
++id;
}
// General case: insert and form facets for each step,
// joining it to the ring below it.
for (size_t s = sbegin + 2; s < send - 1; s++) {
const double z = -rho + increment*double(s*2.0*rho);
const double r = std::sqrt(std::abs(rho*rho - z*z));
for (size_t i = 0; i < ring.size(); i++) {
Vec2d b = Eigen::Rotation2Dd(ring[i]) * Eigen::Vector2d(0, r);
vertices.emplace_back(Vec3d(b(0), b(1), z));
auto id_ringsize = coord_t(id - int(ring.size()));
if (i == 0) {
// wrap around
facets.emplace_back(id - 1, id, id + coord_t(ring.size() - 1) );
facets.emplace_back(id - 1, id_ringsize, id);
} else {
facets.emplace_back(id_ringsize - 1, id_ringsize, id);
facets.emplace_back(id - 1, id_ringsize - 1, id);
}
id++;
}
}
// special case: last ring connects to 0,0,rho*2.0
// only form facets.
if(send >= size_t(2*PI / angle)) {
vertices.emplace_back(Vec3d(0.0, 0.0, -rho + increment*send*2.0*rho));
for (size_t i = 0; i < ring.size(); i++) {
auto id_ringsize = coord_t(id - int(ring.size()));
if (i == 0) {
// third vertex is on the other side of the ring.
facets.emplace_back(id - 1, id_ringsize, id);
} else {
auto ci = coord_t(id_ringsize + coord_t(i));
facets.emplace_back(ci - 1, ci, id);
}
}
}
id++;
return ret;
}
Contour3D cylinder(double r, double h, size_t ssteps, const Vec3d &sp)
{
Contour3D ret;
auto steps = int(ssteps);
auto& points = ret.points;
auto& indices = ret.faces3;
points.reserve(2*ssteps);
double a = 2*PI/steps;
Vec3d jp = sp;
Vec3d endp = {sp(X), sp(Y), sp(Z) + h};
// Upper circle points
for(int i = 0; i < steps; ++i) {
double phi = i*a;
double ex = endp(X) + r*std::cos(phi);
double ey = endp(Y) + r*std::sin(phi);
points.emplace_back(ex, ey, endp(Z));
}
// Lower circle points
for(int i = 0; i < steps; ++i) {
double phi = i*a;
double x = jp(X) + r*std::cos(phi);
double y = jp(Y) + r*std::sin(phi);
points.emplace_back(x, y, jp(Z));
}
// Now create long triangles connecting upper and lower circles
indices.reserve(2*ssteps);
auto offs = steps;
for(int i = 0; i < steps - 1; ++i) {
indices.emplace_back(i, i + offs, offs + i + 1);
indices.emplace_back(i, offs + i + 1, i + 1);
}
// Last triangle connecting the first and last vertices
auto last = steps - 1;
indices.emplace_back(0, last, offs);
indices.emplace_back(last, offs + last, offs);
// According to the slicing algorithms, we need to aid them with generating
// a watertight body. So we create a triangle fan for the upper and lower
// ending of the cylinder to close the geometry.
points.emplace_back(jp); int ci = int(points.size() - 1);
for(int i = 0; i < steps - 1; ++i)
indices.emplace_back(i + offs + 1, i + offs, ci);
indices.emplace_back(offs, steps + offs - 1, ci);
points.emplace_back(endp); ci = int(points.size() - 1);
for(int i = 0; i < steps - 1; ++i)
indices.emplace_back(ci, i, i + 1);
indices.emplace_back(steps - 1, 0, ci);
return ret;
}
Contour3D pinhead(double r_pin, double r_back, double length, size_t steps)
{
assert(length > 0.);
assert(r_back > 0.);
assert(r_pin > 0.);
Contour3D mesh;
// We create two spheres which will be connected with a robe that fits
// both circles perfectly.
// Set up the model detail level
const double detail = 2*PI/steps;
// We don't generate whole circles. Instead, we generate only the
// portions which are visible (not covered by the robe) To know the
// exact portion of the bottom and top circles we need to use some
// rules of tangent circles from which we can derive (using simple
// triangles the following relations:
// The height of the whole mesh
const double h = r_back + r_pin + length;
double phi = PI / 2. - std::acos((r_back - r_pin) / h);
// To generate a whole circle we would pass a portion of (0, Pi)
// To generate only a half horizontal circle we can pass (0, Pi/2)
// The calculated phi is an offset to the half circles needed to smooth
// the transition from the circle to the robe geometry
auto&& s1 = sphere(r_back, make_portion(0, PI/2 + phi), detail);
auto&& s2 = sphere(r_pin, make_portion(PI/2 + phi, PI), detail);
for(auto& p : s2.points) p.z() += h;
mesh.merge(s1);
mesh.merge(s2);
for(size_t idx1 = s1.points.size() - steps, idx2 = s1.points.size();
idx1 < s1.points.size() - 1;
idx1++, idx2++)
{
coord_t i1s1 = coord_t(idx1), i1s2 = coord_t(idx2);
coord_t i2s1 = i1s1 + 1, i2s2 = i1s2 + 1;
mesh.faces3.emplace_back(i1s1, i2s1, i2s2);
mesh.faces3.emplace_back(i1s1, i2s2, i1s2);
}
auto i1s1 = coord_t(s1.points.size()) - coord_t(steps);
auto i2s1 = coord_t(s1.points.size()) - 1;
auto i1s2 = coord_t(s1.points.size());
auto i2s2 = coord_t(s1.points.size()) + coord_t(steps) - 1;
mesh.faces3.emplace_back(i2s2, i2s1, i1s1);
mesh.faces3.emplace_back(i1s2, i2s2, i1s1);
return mesh;
}
Contour3D pedestal(const Vec3d &endpt, double baseheight, double radius, size_t steps)
{
if(baseheight <= 0) return {};
assert(steps >= 0);
auto last = int(steps - 1);
Contour3D base;
double a = 2*PI/steps;
double z = endpt(Z) + baseheight;
for(size_t i = 0; i < steps; ++i) {
double phi = i*a;
double x = endpt(X) + radius * std::cos(phi);
double y = endpt(Y) + radius * std::sin(phi);
base.points.emplace_back(x, y, z);
}
for(size_t i = 0; i < steps; ++i) {
double phi = i*a;
double x = endpt(X) + radius*std::cos(phi);
double y = endpt(Y) + radius*std::sin(phi);
base.points.emplace_back(x, y, z - baseheight);
}
auto ep = endpt; ep(Z) += baseheight;
base.points.emplace_back(endpt);
base.points.emplace_back(ep);
auto& indices = base.faces3;
auto hcenter = int(base.points.size() - 1);
auto lcenter = int(base.points.size() - 2);
auto offs = int(steps);
for(int i = 0; i < last; ++i) {
indices.emplace_back(i, i + offs, offs + i + 1);
indices.emplace_back(i, offs + i + 1, i + 1);
indices.emplace_back(i, i + 1, hcenter);
indices.emplace_back(lcenter, offs + i + 1, offs + i);
}
indices.emplace_back(0, last, offs);
indices.emplace_back(last, offs + last, offs);
indices.emplace_back(hcenter, last, 0);
indices.emplace_back(offs, offs + last, lcenter);
return base;
}
Head::Head(double r_big_mm,
double r_small_mm,
double length_mm,
double penetration,
const Vec3d &direction,
const Vec3d &offset,
const size_t circlesteps)
: steps(circlesteps)
, dir(direction)
, pos(offset)
, r_back_mm(r_big_mm)
, r_pin_mm(r_small_mm)
, width_mm(length_mm)
, penetration_mm(penetration)
{
// mesh = pinhead(r_pin_mm, r_back_mm, width_mm, steps);
// To simplify further processing, we translate the mesh so that the
// last vertex of the pointing sphere (the pinpoint) will be at (0,0,0)
// for(auto& p : mesh.points) p.z() -= (fullwidth() - r_back_mm);
}
//Pillar::Pillar(const Vec3d &endp, double h, double radius, size_t st):
// height{h}, r(radius), steps(st), endpt(endp), starts_from_head(false)
//{
// assert(steps > 0);
// if(height > EPSILON) { // Endpoint is below the starting point
// // We just create a bridge geometry with the pillar parameters and
// // move the data.
// Contour3D body = cylinder(radius, height, st, endp);
// mesh.points.swap(body.points);
// mesh.faces3.swap(body.faces3);
// }
//}
//Pillar &Pillar::add_base(double baseheight, double radius)
//{
// if(baseheight <= 0) return *this;
// if(baseheight > height) baseheight = height;
// assert(steps >= 0);
// auto last = int(steps - 1);
// if(radius < r ) radius = r;
// double a = 2*PI/steps;
// double z = endpt(Z) + baseheight;
// for(size_t i = 0; i < steps; ++i) {
// double phi = i*a;
// double x = endpt(X) + r*std::cos(phi);
// double y = endpt(Y) + r*std::sin(phi);
// base.points.emplace_back(x, y, z);
// }
// for(size_t i = 0; i < steps; ++i) {
// double phi = i*a;
// double x = endpt(X) + radius*std::cos(phi);
// double y = endpt(Y) + radius*std::sin(phi);
// base.points.emplace_back(x, y, z - baseheight);
// }
// auto ep = endpt; ep(Z) += baseheight;
// base.points.emplace_back(endpt);
// base.points.emplace_back(ep);
// auto& indices = base.faces3;
// auto hcenter = int(base.points.size() - 1);
// auto lcenter = int(base.points.size() - 2);
// auto offs = int(steps);
// for(int i = 0; i < last; ++i) {
// indices.emplace_back(i, i + offs, offs + i + 1);
// indices.emplace_back(i, offs + i + 1, i + 1);
// indices.emplace_back(i, i + 1, hcenter);
// indices.emplace_back(lcenter, offs + i + 1, offs + i);
// }
// indices.emplace_back(0, last, offs);
// indices.emplace_back(last, offs + last, offs);
// indices.emplace_back(hcenter, last, 0);
// indices.emplace_back(offs, offs + last, lcenter);
// return *this;
//}
Bridge::Bridge(const Vec3d &j1, const Vec3d &j2, double r_mm, size_t steps):
r(r_mm), startp(j1), endp(j2)
{
using Quaternion = Eigen::Quaternion<double>;
Vec3d dir = (j2 - j1).normalized();
double d = distance(j2, j1);
mesh = cylinder(r, d, steps);
auto quater = Quaternion::FromTwoVectors(Vec3d{0,0,1}, dir);
for(auto& p : mesh.points) p = quater * p + j1;
}
Bridge::Bridge(const Vec3d &j1,
const Vec3d &j2,
double r1_mm,
double r2_mm,
size_t steps)
{
Vec3d dir = (j2 - j1);
mesh = pinhead(r1_mm, r2_mm, dir.norm(), steps);
dir.normalize();
using Quaternion = Eigen::Quaternion<double>;
auto quater = Quaternion::FromTwoVectors(Vec3d{0,0,1}, dir);
for(auto& p : mesh.points) p = quater * p + j1;
}
Pad::Pad(const TriangleMesh &support_mesh,
const ExPolygons & model_contours,
double ground_level,
const PadConfig & pcfg,
ThrowOnCancel thr)
: cfg(pcfg)
, zlevel(ground_level + pcfg.full_height() - pcfg.required_elevation())
{
thr();
ExPolygons sup_contours;
float zstart = float(zlevel);
float zend = zstart + float(pcfg.full_height() + EPSILON);
pad_blueprint(support_mesh, sup_contours, grid(zstart, zend, 0.1f), thr);
create_pad(sup_contours, model_contours, tmesh, pcfg);
tmesh.translate(0, 0, float(zlevel));
if (!tmesh.empty()) tmesh.require_shared_vertices();
}
const TriangleMesh &SupportTreeBuilder::add_pad(const ExPolygons &modelbase,
const PadConfig & cfg)
{
m_pad = Pad{merged_mesh(), modelbase, ground_level, cfg, ctl().cancelfn};
return m_pad.tmesh;
}
SupportTreeBuilder::SupportTreeBuilder(SupportTreeBuilder &&o)
: m_heads(std::move(o.m_heads))
, m_head_indices{std::move(o.m_head_indices)}
, m_pillars{std::move(o.m_pillars)}
, m_bridges{std::move(o.m_bridges)}
, m_crossbridges{std::move(o.m_crossbridges)}
, m_pad{std::move(o.m_pad)}
, m_meshcache{std::move(o.m_meshcache)}
, m_meshcache_valid{o.m_meshcache_valid}
, m_model_height{o.m_model_height}
, ground_level{o.ground_level}
{}
SupportTreeBuilder::SupportTreeBuilder(const SupportTreeBuilder &o)
: m_heads(o.m_heads)
, m_head_indices{o.m_head_indices}
, m_pillars{o.m_pillars}
, m_bridges{o.m_bridges}
, m_crossbridges{o.m_crossbridges}
, m_pad{o.m_pad}
, m_meshcache{o.m_meshcache}
, m_meshcache_valid{o.m_meshcache_valid}
, m_model_height{o.m_model_height}
, ground_level{o.ground_level}
{}
SupportTreeBuilder &SupportTreeBuilder::operator=(SupportTreeBuilder &&o)
{
m_heads = std::move(o.m_heads);
m_head_indices = std::move(o.m_head_indices);
m_pillars = std::move(o.m_pillars);
m_bridges = std::move(o.m_bridges);
m_crossbridges = std::move(o.m_crossbridges);
m_pad = std::move(o.m_pad);
m_meshcache = std::move(o.m_meshcache);
m_meshcache_valid = o.m_meshcache_valid;
m_model_height = o.m_model_height;
ground_level = o.ground_level;
return *this;
}
SupportTreeBuilder &SupportTreeBuilder::operator=(const SupportTreeBuilder &o)
{
m_heads = o.m_heads;
m_head_indices = o.m_head_indices;
m_pillars = o.m_pillars;
m_bridges = o.m_bridges;
m_crossbridges = o.m_crossbridges;
m_pad = o.m_pad;
m_meshcache = o.m_meshcache;
m_meshcache_valid = o.m_meshcache_valid;
m_model_height = o.m_model_height;
ground_level = o.ground_level;
return *this;
}
const TriangleMesh &SupportTreeBuilder::merged_mesh() const
{
if (m_meshcache_valid) return m_meshcache;
Contour3D merged;
for (auto &head : m_heads) {
if (ctl().stopcondition()) break;
if (head.is_valid()) merged.merge(get_mesh(head));
}
for (auto &stick : m_pillars) {
if (ctl().stopcondition()) break;
merged.merge(stick.mesh);
merged.merge(stick.base);
}
for (auto &j : m_junctions) {
if (ctl().stopcondition()) break;
merged.merge(j.mesh);
}
for (auto &bs : m_bridges) {
if (ctl().stopcondition()) break;
merged.merge(bs.mesh);
}
for (auto &bs : m_crossbridges) {
if (ctl().stopcondition()) break;
merged.merge(bs.mesh);
}
if (ctl().stopcondition()) {
// In case of failure we have to return an empty mesh
m_meshcache = TriangleMesh();
return m_meshcache;
}
m_meshcache = to_triangle_mesh(merged);
// The mesh will be passed by const-pointer to TriangleMeshSlicer,
// which will need this.
if (!m_meshcache.empty()) m_meshcache.require_shared_vertices();
BoundingBoxf3 &&bb = m_meshcache.bounding_box();
m_model_height = bb.max(Z) - bb.min(Z);
m_meshcache_valid = true;
return m_meshcache;
}
double SupportTreeBuilder::full_height() const
{
if (merged_mesh().empty() && !pad().empty())
return pad().cfg.full_height();
double h = mesh_height();
if (!pad().empty()) h += pad().cfg.required_elevation();
return h;
}
const TriangleMesh &SupportTreeBuilder::merge_and_cleanup()
{
// in case the mesh is not generated, it should be...
auto &ret = merged_mesh();
// Doing clear() does not garantee to release the memory.
m_heads = {};
m_head_indices = {};
m_pillars = {};
m_junctions = {};
m_bridges = {};
return ret;
}
const TriangleMesh &SupportTreeBuilder::retrieve_mesh(MeshType meshtype) const
{
switch(meshtype) {
case MeshType::Support: return merged_mesh();
case MeshType::Pad: return pad().tmesh;
}
return m_meshcache;
}
template<class C, class Hit = EigenMesh3D::hit_result>
static Hit min_hit(const C &hits)
{
auto mit = std::min_element(hits.begin(), hits.end(),
[](const Hit &h1, const Hit &h2) {
return h1.distance() < h2.distance();
});
return *mit;
}
}} // namespace Slic3r::sla