BambuStudio/libslic3r/SLA/SupportTreeBuildsteps.hpp

379 lines
14 KiB
C++

#ifndef SLASUPPORTTREEALGORITHM_H
#define SLASUPPORTTREEALGORITHM_H
#include <cstdint>
#include <optional>
#include <libslic3r/SLA/SupportTreeBuilder.hpp>
#include <libslic3r/SLA/Clustering.hpp>
#include <libslic3r/SLA/SpatIndex.hpp>
namespace Slic3r {
namespace sla {
// The minimum distance for two support points to remain valid.
const double /*constexpr*/ D_SP = 0.1;
enum { // For indexing Eigen vectors as v(X), v(Y), v(Z) instead of numbers
X, Y, Z
};
inline Vec2d to_vec2(const Vec3d &v3) { return {v3(X), v3(Y)}; }
inline std::pair<double, double> dir_to_spheric(const Vec3d &n, double norm = 1.)
{
double z = n.z();
double r = norm;
double polar = std::acos(z / r);
double azimuth = std::atan2(n(1), n(0));
return {polar, azimuth};
}
inline Vec3d spheric_to_dir(double polar, double azimuth)
{
return {std::cos(azimuth) * std::sin(polar),
std::sin(azimuth) * std::sin(polar), std::cos(polar)};
}
inline Vec3d spheric_to_dir(const std::tuple<double, double> &v)
{
auto [plr, azm] = v;
return spheric_to_dir(plr, azm);
}
inline Vec3d spheric_to_dir(const std::pair<double, double> &v)
{
return spheric_to_dir(v.first, v.second);
}
inline Vec3d spheric_to_dir(const std::array<double, 2> &v)
{
return spheric_to_dir(v[0], v[1]);
}
// Give points on a 3D ring with given center, radius and orientation
// method based on:
// https://math.stackexchange.com/questions/73237/parametric-equation-of-a-circle-in-3d-space
template<size_t N>
class PointRing {
std::array<double, N> m_phis;
// Two vectors that will be perpendicular to each other and to the
// axis. Values for a(X) and a(Y) are now arbitrary, a(Z) is just a
// placeholder.
// a and b vectors are perpendicular to the ring direction and to each other.
// Together they define the plane where we have to iterate with the
// given angles in the 'm_phis' vector
Vec3d a = {0, 1, 0}, b;
double m_radius = 0.;
static inline bool constexpr is_one(double val)
{
return std::abs(std::abs(val) - 1) < 1e-20;
}
public:
PointRing(const Vec3d &n)
{
m_phis = linspace_array<N>(0., 2 * PI);
// We have to address the case when the direction vector v (same as
// dir) is coincident with one of the world axes. In this case two of
// its components will be completely zero and one is 1.0. Our method
// becomes dangerous here due to division with zero. Instead, vector
// 'a' can be an element-wise rotated version of 'v'
if(is_one(n(X)) || is_one(n(Y)) || is_one(n(Z))) {
a = {n(Z), n(X), n(Y)};
b = {n(Y), n(Z), n(X)};
}
else {
a(Z) = -(n(Y)*a(Y)) / n(Z); a.normalize();
b = a.cross(n);
}
}
Vec3d get(size_t idx, const Vec3d src, double r) const
{
double phi = m_phis[idx];
double sinphi = std::sin(phi);
double cosphi = std::cos(phi);
double rpscos = r * cosphi;
double rpssin = r * sinphi;
// Point on the sphere
return {src(X) + rpscos * a(X) + rpssin * b(X),
src(Y) + rpscos * a(Y) + rpssin * b(Y),
src(Z) + rpscos * a(Z) + rpssin * b(Z)};
}
};
//IndexedMesh::hit_result query_hit(const SupportableMesh &msh, const Bridge &br, double safety_d = std::nan(""));
//IndexedMesh::hit_result query_hit(const SupportableMesh &msh, const Head &br, double safety_d = std::nan(""));
inline Vec3d dirv(const Vec3d& startp, const Vec3d& endp) {
return (endp - startp).normalized();
}
class PillarIndex {
PointIndex m_index;
using Mutex = ccr::BlockingMutex;
mutable Mutex m_mutex;
public:
template<class...Args> inline void guarded_insert(Args&&...args)
{
std::lock_guard<Mutex> lck(m_mutex);
m_index.insert(std::forward<Args>(args)...);
}
template<class...Args>
inline std::vector<PointIndexEl> guarded_query(Args&&...args) const
{
std::lock_guard<Mutex> lck(m_mutex);
return m_index.query(std::forward<Args>(args)...);
}
template<class...Args> inline void insert(Args&&...args)
{
m_index.insert(std::forward<Args>(args)...);
}
template<class...Args>
inline std::vector<PointIndexEl> query(Args&&...args) const
{
return m_index.query(std::forward<Args>(args)...);
}
template<class Fn> inline void foreach(Fn fn) { m_index.foreach(fn); }
template<class Fn> inline void guarded_foreach(Fn fn)
{
std::lock_guard<Mutex> lck(m_mutex);
m_index.foreach(fn);
}
PointIndex guarded_clone()
{
std::lock_guard<Mutex> lck(m_mutex);
return m_index;
}
};
// Helper function for pillar interconnection where pairs of already connected
// pillars should be checked for not to be processed again. This can be done
// in constant time with a set of hash values uniquely representing a pair of
// integers. The order of numbers within the pair should not matter, it has
// the same unique hash. The hash value has to have twice as many bits as the
// arguments need. If the same integral type is used for args and return val,
// make sure the arguments use only the half of the type's bit depth.
template<class I, class DoubleI = IntegerOnly<I>>
IntegerOnly<DoubleI> pairhash(I a, I b)
{
using std::ceil; using std::log2; using std::max; using std::min;
static const auto constexpr Ibits = int(sizeof(I) * CHAR_BIT);
static const auto constexpr DoubleIbits = int(sizeof(DoubleI) * CHAR_BIT);
static const auto constexpr shift = DoubleIbits / 2 < Ibits ? Ibits / 2 : Ibits;
I g = min(a, b), l = max(a, b);
// Assume the hash will fit into the output variable
assert((g ? (ceil(log2(g))) : 0) <= shift);
assert((l ? (ceil(log2(l))) : 0) <= shift);
return (DoubleI(g) << shift) + l;
}
class SupportTreeBuildsteps {
const SupportTreeConfig& m_cfg;
const IndexedMesh& m_mesh;
const std::vector<SupportPoint>& m_support_pts;
using PtIndices = std::vector<unsigned>;
PtIndices m_iheads; // support points with pinhead
PtIndices m_iheads_onmodel;
PtIndices m_iheadless; // headless support points
std::map<unsigned, IndexedMesh::hit_result> m_head_to_ground_scans;
// normals for support points from model faces.
PointSet m_support_nmls;
// Clusters of points which can reach the ground directly and can be
// bridged to one central pillar
std::vector<PtIndices> m_pillar_clusters;
// This algorithm uses the SupportTreeBuilder class to fill gradually
// the support elements (heads, pillars, bridges, ...)
SupportTreeBuilder& m_builder;
// support points in Eigen/IGL format
PointSet m_points;
// throw if canceled: It will be called many times so a shorthand will
// come in handy.
ThrowOnCancel m_thr;
// A spatial index to easily find strong pillars to connect to.
PillarIndex m_pillar_index;
// When bridging heads to pillars... TODO: find a cleaner solution
ccr::BlockingMutex m_bridge_mutex;
inline IndexedMesh::hit_result ray_mesh_intersect(const Vec3d& s,
const Vec3d& dir)
{
return m_mesh.query_ray_hit(s, dir);
}
// This function will test if a future pinhead would not collide with the
// model geometry. It does not take a 'Head' object because those are
// created after this test. Parameters: s: The touching point on the model
// surface. dir: This is the direction of the head from the pin to the back
// r_pin, r_back: the radiuses of the pin and the back sphere width: This
// is the full width from the pin center to the back center m: The object
// mesh.
// The return value is the hit result from the ray casting. If the starting
// point was inside the model, an "invalid" hit_result will be returned
// with a zero distance value instead of a NAN. This way the result can
// be used safely for comparison with other distances.
IndexedMesh::hit_result pinhead_mesh_intersect(
const Vec3d& s,
const Vec3d& dir,
double r_pin,
double r_back,
double width,
double safety_d);
IndexedMesh::hit_result pinhead_mesh_intersect(
const Vec3d& s,
const Vec3d& dir,
double r_pin,
double r_back,
double width)
{
return pinhead_mesh_intersect(s, dir, r_pin, r_back, width,
r_back * m_cfg.safety_distance_mm /
m_cfg.head_back_radius_mm);
}
// Checking bridge (pillar and stick as well) intersection with the model.
// If the function is used for headless sticks, the ins_check parameter
// have to be true as the beginning of the stick might be inside the model
// geometry.
// The return value is the hit result from the ray casting. If the starting
// point was inside the model, an "invalid" hit_result will be returned
// with a zero distance value instead of a NAN. This way the result can
// be used safely for comparison with other distances.
IndexedMesh::hit_result bridge_mesh_intersect(
const Vec3d& s,
const Vec3d& dir,
double r,
double safety_d);
IndexedMesh::hit_result bridge_mesh_intersect(
const Vec3d& s,
const Vec3d& dir,
double r)
{
return bridge_mesh_intersect(s, dir, r,
r * m_cfg.safety_distance_mm /
m_cfg.head_back_radius_mm);
}
template<class...Args>
inline double bridge_mesh_distance(Args&&...args) {
return bridge_mesh_intersect(std::forward<Args>(args)...).distance();
}
// Helper function for interconnecting two pillars with zig-zag bridges.
bool interconnect(const Pillar& pillar, const Pillar& nextpillar);
// For connecting a head to a nearby pillar.
bool connect_to_nearpillar(const Head& head, long nearpillar_id);
// Find route for a head to the ground. Inserts additional bridge from the
// head to the pillar if cannot create pillar directly.
// The optional dir parameter is the direction of the bridge which is the
// direction of the pinhead if omitted.
bool connect_to_ground(Head& head, const Vec3d &dir);
inline bool connect_to_ground(Head& head);
bool connect_to_model_body(Head &head);
bool search_pillar_and_connect(const Head& source);
// This is a proxy function for pillar creation which will mind the gap
// between the pad and the model bottom in zero elevation mode.
// jp is the starting junction point which needs to be routed down.
// sourcedir is the allowed direction of an optional bridge between the
// jp junction and the final pillar.
bool create_ground_pillar(const Vec3d &jp,
const Vec3d &sourcedir,
double radius,
long head_id = SupportTreeNode::ID_UNSET);
void add_pillar_base(long pid)
{
m_builder.add_pillar_base(pid, m_cfg.base_height_mm, m_cfg.base_radius_mm);
}
std::optional<DiffBridge> search_widening_path(const Vec3d &jp,
const Vec3d &dir,
double radius,
double new_radius);
public:
SupportTreeBuildsteps(SupportTreeBuilder & builder, const SupportableMesh &sm);
// Now let's define the individual steps of the support generation algorithm
// Filtering step: here we will discard inappropriate support points
// and decide the future of the appropriate ones. We will check if a
// pinhead is applicable and adjust its angle at each support point. We
// will also merge the support points that are just too close and can
// be considered as one.
void filter();
// Pinhead creation: based on the filtering results, the Head objects
// will be constructed (together with their triangle meshes).
void add_pinheads();
// Further classification of the support points with pinheads. If the
// ground is directly reachable through a vertical line parallel to the
// Z axis we consider a support point as pillar candidate. If touches
// the model geometry, it will be marked as non-ground facing and
// further steps will process it. Also, the pillars will be grouped
// into clusters that can be interconnected with bridges. Elements of
// these groups may or may not be interconnected. Here we only run the
// clustering algorithm.
void classify();
// Step: Routing the ground connected pinheads, and interconnecting
// them with additional (angled) bridges. Not all of these pinheads
// will be a full pillar (ground connected). Some will connect to a
// nearby pillar using a bridge. The max number of such side-heads for
// a central pillar is limited to avoid bad weight distribution.
void routing_to_ground();
// Step: routing the pinheads that would connect to the model surface
// along the Z axis downwards. For now these will actually be connected with
// the model surface with a flipped pinhead. In the future here we could use
// some smart algorithms to search for a safe path to the ground or to a
// nearby pillar that can hold the supported weight.
void routing_to_model();
void interconnect_pillars();
inline void merge_result() { m_builder.merged_mesh(); }
static bool execute(SupportTreeBuilder & builder, const SupportableMesh &sm);
};
}
}
#endif // SLASUPPORTTREEALGORITHM_H