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EigenMesh3D raycaster should now be able to pick a correct intersection on the object or inside a hole

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This commit is contained in:
Lukas Matena 2019-11-19 14:27:05 +01:00
parent 9dd18a8d6d
commit 2c1d256b0c
5 changed files with 147 additions and 57 deletions
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108
src/libslic3r/SLA/Common.cpp
View file

@ -183,18 +183,6 @@ void BoxIndex::foreach(std::function<void (const BoxIndexEl &)> fn)
}
namespace {
// Iterates over hits and holes and returns the true hit, possibly
// on the inside of a hole. Free function so it can return igl::Hit
// without including igl in a header.
igl::Hit filter_hits(const std::vector<EigenMesh3D::hit_result>& hits,
const std::vector<DrainHole>& holes)
{
return igl::Hit();
}
} // namespace
/* ****************************************************************************
* EigenMesh3D implementation
* ****************************************************************************/
@ -280,22 +268,27 @@ EigenMesh3D::query_ray_hit(const Vec3d &s,
const std::vector<DrainHole>* holes
) const
{
assert(is_approx(dir.norm(), 1.));
igl::Hit hit;
hit.t = std::numeric_limits<float>::infinity();
if (! holes)
if (! holes) {
m_aabb->intersect_ray(m_V, m_F, s, dir, hit);
else
hit = filter_hits(query_ray_hits(s, dir), *holes);
hit_result ret(*this);
ret.m_t = double(hit.t);
ret.m_dir = dir;
ret.m_source = s;
if(!std::isinf(hit.t) && !std::isnan(hit.t)) ret.m_face_id = hit.id;
if(!std::isinf(hit.t) && !std::isnan(hit.t))
ret.m_normal = this->normal_by_face_id(hit.id);
return ret;
}
else {
// If there are holes, the hit_results will be made by
// query_ray_hits (object) and filter_hits (holes):
return filter_hits(query_ray_hits(s, dir), *holes);
}
}
std::vector<EigenMesh3D::hit_result>
EigenMesh3D::query_ray_hits(const Vec3d &s, const Vec3d &dir) const
@ -316,12 +309,91 @@ EigenMesh3D::query_ray_hits(const Vec3d &s, const Vec3d &dir) const
outs.back().m_dir = dir;
outs.back().m_source = s;
if(!std::isinf(hit.t) && !std::isnan(hit.t))
outs.back().m_face_id = hit.id;
outs.back().m_normal = this->normal_by_face_id(hit.id);
}
return outs;
}
EigenMesh3D::hit_result EigenMesh3D::filter_hits(
const std::vector<EigenMesh3D::hit_result>& object_hits,
const std::vector<DrainHole>& holes) const
{
hit_result out(*this);
out.m_t = std::nan("");
if (! holes.empty() && ! object_hits.empty()) {
Vec3d s = object_hits.front().source();
Vec3d dir = object_hits.front().direction();
struct HoleHit {
HoleHit(float t_p, const Vec3d& normal_p, bool entry_p) :
t(t_p), normal(normal_p), entry(entry_p) {}
float t;
Vec3d normal;
bool entry;
};
std::vector<HoleHit> hole_isects;
// Collect hits on all holes, preserve information about entry/exit
for (const sla::DrainHole& hole : holes) {
std::array<std::pair<float, Vec3d>, 2> isects;
if (hole.get_intersections(s.cast<float>(),
dir.cast<float>(), isects)) {
hole_isects.emplace_back(isects[0].first, isects[0].second, true);
hole_isects.emplace_back(isects[1].first, isects[1].second, false);
}
}
// Holes can intersect each other, sort the hits by t
std::sort(hole_isects.begin(), hole_isects.end(),
[](const HoleHit& a, const HoleHit& b) { return a.t < b.t; });
// Now inspect the intersections with object and holes, keep track how
// deep are we nested in mesh/holes and pick the correct intersection
int hole_nested = 0;
int object_nested = 0;
bool is_hole = false;
bool is_entry = false;
const HoleHit* next_hole_hit = &hole_isects.front();
const hit_result* next_mesh_hit = &object_hits.front();
while (next_hole_hit || next_mesh_hit) {
if (next_hole_hit && next_mesh_hit) // still have hole and obj hits
is_hole = (next_hole_hit->t < next_mesh_hit->m_t);
else
is_hole = next_hole_hit; // one or the other ran out
// Is this entry or exit hit?
is_entry = is_hole ? next_hole_hit->entry : ! next_mesh_hit->is_inside();
if (! is_hole && is_entry && hole_nested == 0) {
// This mesh point is the one we seek
return *next_mesh_hit;
}
if (is_hole && ! is_entry && object_nested != 0) {
// This holehit is the one we seek
out.m_t = next_hole_hit->t;
out.m_normal = next_hole_hit->normal;
out.m_source = s;
out.m_dir = dir;
return out;
}
hole_nested += (is_hole ? (is_entry ? 1 : -1) : 0);
object_nested += (! is_hole ? (is_entry ? 1 : -1) : 0);
// Advance the pointer
if (is_hole && next_hole_hit++ == &hole_isects.back())
next_hole_hit = nullptr;
if (! is_hole && next_mesh_hit++ == &object_hits.back())
next_mesh_hit = nullptr;
}
}
return out;
}
#ifdef SLIC3R_SLA_NEEDS_WINDTREE
EigenMesh3D::si_result EigenMesh3D::signed_distance(const Vec3d &p) const {
double sign = 0; double sqdst = 0; int i = 0; Vec3d c;

38
src/libslic3r/SLA/EigenMesh3D.hpp
View file

@ -42,10 +42,10 @@ public:
// Result of a raycast
class hit_result {
double m_t = std::nan("");
int m_face_id = -1;
const EigenMesh3D *m_mesh = nullptr;
Vec3d m_dir;
Vec3d m_source;
Vec3d m_normal = Vec3d::Zero();
friend class EigenMesh3D;
// A valid object of this class can only be obtained from
@ -60,26 +60,23 @@ public:
inline double distance() const { return m_t; }
inline const Vec3d& direction() const { return m_dir; }
inline const Vec3d& source() const { return m_source; }
inline Vec3d position() const { return m_source + m_dir * m_t; }
inline int face() const { return m_face_id; }
inline bool is_valid() const { return m_mesh != nullptr; }
inline bool is_hit() const { return m_normal != Vec3d::Zero(); }
// Hit_result can decay into a double as the hit distance.
inline operator double() const { return distance(); }
inline Vec3d normal() const {
if(m_face_id < 0 || !is_valid()) return {};
auto trindex = m_mesh->m_F.row(m_face_id);
const Vec3d& p1 = m_mesh->V().row(trindex(0));
const Vec3d& p2 = m_mesh->V().row(trindex(1));
const Vec3d& p3 = m_mesh->V().row(trindex(2));
Eigen::Vector3d U = p2 - p1;
Eigen::Vector3d V = p3 - p1;
return U.cross(V).normalized();
inline const Vec3d& normal() const {
if(!is_valid())
throw std::runtime_error("EigenMesh3D::hit_result::normal() "
"called on invalid object.");
return m_normal;
}
inline bool is_inside() {
return m_face_id >= 0 && normal().dot(m_dir) > 0;
inline bool is_inside() const {
return normal().dot(m_dir) > 0;
}
};
@ -91,6 +88,11 @@ public:
// Casts a ray on the mesh and returns all hits
std::vector<hit_result> query_ray_hits(const Vec3d &s, const Vec3d &dir) const;
// Iterates over hits and holes and returns the true hit, possibly
// on the inside of a hole.
hit_result filter_hits(const std::vector<EigenMesh3D::hit_result>& obj_hits,
const std::vector<DrainHole>& holes) const;
class si_result {
double m_value;
int m_fidx;
@ -123,6 +125,16 @@ public:
Vec3d c;
return squared_distance(p, i, c);
}
Vec3d normal_by_face_id(int face_id) const {
auto trindex = F().row(face_id);
const Vec3d& p1 = V().row(trindex(0));
const Vec3d& p2 = V().row(trindex(1));
const Vec3d& p3 = V().row(trindex(2));
Eigen::Vector3d U = p2 - p1;
Eigen::Vector3d V = p3 - p1;
return U.cross(V).normalized();
}
};
// Calculate the normals for the selected points (from 'points' set) on the

33
src/libslic3r/SLA/Hollowing.cpp
View file

@ -141,22 +141,26 @@ bool DrainHole::is_inside(const Vec3f& pt) const
}
// Given a line s+dir*t, return parameter t of intersections with the hole.
// If there is no intersection, returns nan.
std::pair<float, float> DrainHole::get_intersections(const Vec3f& s,
const Vec3f& dir) const
// Given a line s+dir*t, find parameter t of intersections with the hole
// and the normal (points inside the hole). Outputs through out reference,
// returns true if two intersections were found.
bool DrainHole::get_intersections(const Vec3f& s, const Vec3f& dir,
std::array<std::pair<float, Vec3d>, 2>& out)
const
{
assert(is_approx(normal.norm(), 1.f));
const Eigen::ParametrizedLine<float, 3> ray(s, dir.normalized());
std::pair<float, float> out(std::nan(""), std::nan(""));
for (size_t i=0; i<2; ++i)
out[i] = std::make_pair(std::nan(""), Vec3d::Zero());
const float sqr_radius = pow(radius, 2.f);
// first check a bounding sphere of the hole:
Vec3f center = pos+normal*height/2.f;
float sqr_dist_limit = pow(height/2.f, 2.f) + sqr_radius ;
if (ray.squaredDistance(center) > sqr_dist_limit)
return out;
return false;
// The line intersects the bounding sphere, look for intersections with
// bases of the cylinder.
@ -170,7 +174,8 @@ std::pair<float, float> DrainHole::get_intersections(const Vec3f& s,
Vec3f intersection = ray.intersectionPoint(base);
// Only accept the point if it is inside the cylinder base.
if ((cylinder_center-intersection).squaredNorm() < sqr_radius) {
(found ? out.second : out.first) = ray.intersectionParameter(base);
out[found].first = ray.intersectionParameter(base);
out[found].second = (i==0 ? 1. : -1.) * normal.cast<double>();
++found;
}
}
@ -200,11 +205,13 @@ std::pair<float, float> DrainHole::get_intersections(const Vec3f& s,
for (int i=-1; i<=1 && found !=2; i+=2) {
Vec3f isect = closest + i*dist * projected_ray.direction();
float par = (isect-proj_origin).norm() / par_scale;
Vec3d hit_normal = (pos-isect).normalized().cast<double>();
isect = ray.pointAt(par);
// check that the intersection is between the base planes:
float vert_dist = base.signedDistance(isect);
if (vert_dist > 0.f && vert_dist < height) {
(found ? out.second : out.first) = par;
out[found].first = par;
out[found].second = hit_normal;
++found;
}
}
@ -212,14 +219,14 @@ std::pair<float, float> DrainHole::get_intersections(const Vec3f& s,
// If only one intersection was found, it is some corner case,
// no intersection will be returned:
if (found != 0)
return std::pair<float, float>(std::nan(""), std::nan(""));
if (found != 2)
return false;
// Sort the intersections:
if (out.first > out.second)
std::swap(out.first, out.second);
if (out[0].first > out[1].first)
std::swap(out[0], out[1]);
return out;
return true;
}
}} // namespace Slic3r::sla

5
src/libslic3r/SLA/Hollowing.hpp
View file

@ -39,9 +39,8 @@ struct DrainHole
bool is_inside(const Vec3f& pt) const;
std::pair<float, float> get_intersections(const Vec3f& s,
const Vec3f& dir
) const;
bool get_intersections(const Vec3f& s, const Vec3f& dir,
std::array<std::pair<float, Vec3d>, 2>& out) const;
template<class Archive> inline void serialize(Archive &ar)
{

4
src/libslic3r/SLA/SupportPointGenerator.cpp
View file

@ -83,8 +83,8 @@ void SupportPointGenerator::project_onto_mesh(std::vector<sla::SupportPoint>& po
sla::EigenMesh3D::hit_result hit_up = m_emesh.query_ray_hit(p.cast<double>(), Vec3d(0., 0., 1.));
sla::EigenMesh3D::hit_result hit_down = m_emesh.query_ray_hit(p.cast<double>(), Vec3d(0., 0., -1.));
bool up = hit_up.face() != -1;
bool down = hit_down.face() != -1;
bool up = hit_up.is_hit();
bool down = hit_down.is_hit();
if (!up && !down)
continue;