dust3d/third_party/libigl/include/igl/scaf.cpp

707 lines
21 KiB
C++

// This file is part of libigl, a simple c++ geometry processing library.
//
// Copyright (C) 2018 Zhongshi Jiang <jiangzs@nyu.edu>
//
// This Source Code Form is subject to the terms of the Mozilla Public License
// v. 2.0. If a copy of the MPL was not distributed with this file, You can
// obtain one at http://mozilla.org/MPL/2.0/.
#include "scaf.h"
#include <Eigen/Dense>
#include <Eigen/IterativeLinearSolvers>
#include <Eigen/Sparse>
#include <Eigen/SparseCholesky>
#include <Eigen/SparseQR>
#include <igl/PI.h>
#include <igl/Timer.h>
#include <igl/boundary_loop.h>
#include <igl/cat.h>
#include <igl/doublearea.h>
#include <igl/flip_avoiding_line_search.h>
#include <igl/flipped_triangles.h>
#include <igl/grad.h>
#include <igl/harmonic.h>
#include <igl/local_basis.h>
#include <igl/map_vertices_to_circle.h>
#include <igl/polar_svd.h>
#include <igl/slice.h>
#include <igl/slice_into.h>
#include <igl/slim.h>
#include <igl/triangle/triangulate.h>
#include "mapping_energy_with_jacobians.h"
#include <iostream>
#include <map>
#include <algorithm>
#include <set>
#include <vector>
namespace igl
{
namespace scaf
{
void update_scaffold(igl::SCAFData &s)
{
s.mv_num = s.m_V.rows();
s.mf_num = s.m_T.rows();
s.v_num = s.w_uv.rows();
s.sf_num = s.s_T.rows();
s.sv_num = s.v_num - s.mv_num;
s.f_num = s.sf_num + s.mf_num;
s.s_M = Eigen::VectorXd::Constant(s.sf_num, s.scaffold_factor);
}
void adjusted_grad(Eigen::MatrixXd &V,
Eigen::MatrixXi &F,
double area_threshold,
Eigen::SparseMatrix<double> &Dx,
Eigen::SparseMatrix<double> &Dy,
Eigen::SparseMatrix<double> &Dz)
{
Eigen::VectorXd M;
igl::doublearea(V, F, M);
std::vector<int> degen;
for (int i = 0; i < M.size(); i++)
if (M(i) < area_threshold)
degen.push_back(i);
Eigen::SparseMatrix<double> G;
igl::grad(V, F, G);
Dx = G.topRows(F.rows());
Dy = G.block(F.rows(), 0, F.rows(), V.rows());
Dz = G.bottomRows(F.rows());
// handcraft uniform gradient for faces area falling below threshold.
double sin60 = std::sin(igl::PI / 3);
double cos60 = std::cos(igl::PI / 3);
double deno = std::sqrt(sin60 * area_threshold);
Eigen::MatrixXd standard_grad(3, 3);
standard_grad << -sin60 / deno, sin60 / deno, 0,
-cos60 / deno, -cos60 / deno, 1 / deno,
0, 0, 0;
for (auto k : degen)
for (int j = 0; j < 3; j++)
{
Dx.coeffRef(k, F(k, j)) = standard_grad(0, j);
Dy.coeffRef(k, F(k, j)) = standard_grad(1, j);
Dz.coeffRef(k, F(k, j)) = standard_grad(2, j);
}
}
void compute_scaffold_gradient_matrix(SCAFData &s,
Eigen::SparseMatrix<double> &D1,
Eigen::SparseMatrix<double> &D2)
{
using namespace Eigen;
Eigen::SparseMatrix<double> G;
MatrixXi F_s = s.s_T;
int vn = s.v_num;
MatrixXd V = MatrixXd::Zero(vn, 3);
V.leftCols(2) = s.w_uv;
double min_bnd_edge_len = INFINITY;
int acc_bnd = 0;
for (int i = 0; i < s.bnd_sizes.size(); i++)
{
int current_size = s.bnd_sizes[i];
for (int e = acc_bnd; e < acc_bnd + current_size - 1; e++)
{
min_bnd_edge_len = (std::min)(min_bnd_edge_len,
(s.w_uv.row(s.internal_bnd(e)) -
s.w_uv.row(s.internal_bnd(e + 1)))
.squaredNorm());
}
min_bnd_edge_len = (std::min)(min_bnd_edge_len,
(s.w_uv.row(s.internal_bnd(acc_bnd)) -
s.w_uv.row(s.internal_bnd(acc_bnd + current_size - 1)))
.squaredNorm());
acc_bnd += current_size;
}
double area_threshold = min_bnd_edge_len / 4.0;
Eigen::SparseMatrix<double> Dx, Dy, Dz;
adjusted_grad(V, F_s, area_threshold, Dx, Dy, Dz);
MatrixXd F1, F2, F3;
igl::local_basis(V, F_s, F1, F2, F3);
D1 = F1.col(0).asDiagonal() * Dx + F1.col(1).asDiagonal() * Dy +
F1.col(2).asDiagonal() * Dz;
D2 = F2.col(0).asDiagonal() * Dx + F2.col(1).asDiagonal() * Dy +
F2.col(2).asDiagonal() * Dz;
}
void mesh_improve(igl::SCAFData &s)
{
using namespace Eigen;
MatrixXd m_uv = s.w_uv.topRows(s.mv_num);
MatrixXd V_bnd;
V_bnd.resize(s.internal_bnd.size(), 2);
for (int i = 0; i < s.internal_bnd.size(); i++) // redoing step 1.
{
V_bnd.row(i) = m_uv.row(s.internal_bnd(i));
}
if (s.rect_frame_V.size() == 0)
{
Matrix2d ob; // = rect_corners;
{
VectorXd uv_max = m_uv.colwise().maxCoeff();
VectorXd uv_min = m_uv.colwise().minCoeff();
VectorXd uv_mid = (uv_max + uv_min) / 2.;
Eigen::Array2d scaf_range(3, 3);
ob.row(0) = uv_mid.array() + scaf_range * ((uv_min - uv_mid).array());
ob.row(1) = uv_mid.array() + scaf_range * ((uv_max - uv_mid).array());
}
Vector2d rect_len;
rect_len << ob(1, 0) - ob(0, 0), ob(1, 1) - ob(0, 1);
int frame_points = 5;
s.rect_frame_V.resize(4 * frame_points, 2);
for (int i = 0; i < frame_points; i++)
{
// 0,0;0,1
s.rect_frame_V.row(i) << ob(0, 0), ob(0, 1) + i * rect_len(1) / frame_points;
// 0,0;1,1
s.rect_frame_V.row(i + frame_points)
<< ob(0, 0) + i * rect_len(0) / frame_points,
ob(1, 1);
// 1,0;1,1
s.rect_frame_V.row(i + 2 * frame_points) << ob(1, 0), ob(1, 1) - i * rect_len(1) / frame_points;
// 1,0;0,1
s.rect_frame_V.row(i + 3 * frame_points)
<< ob(1, 0) - i * rect_len(0) / frame_points,
ob(0, 1);
// 0,0;0,1
}
s.frame_ids = Eigen::VectorXi::LinSpaced(s.rect_frame_V.rows(), s.mv_num, s.mv_num + s.rect_frame_V.rows());
}
// Concatenate Vert and Edge
MatrixXd V;
MatrixXi E;
igl::cat(1, V_bnd, s.rect_frame_V, V);
E.resize(V.rows(), 2);
for (int i = 0; i < E.rows(); i++)
E.row(i) << i, i + 1;
int acc_bs = 0;
for (auto bs : s.bnd_sizes)
{
E(acc_bs + bs - 1, 1) = acc_bs;
acc_bs += bs;
}
E(V.rows() - 1, 1) = acc_bs;
assert(acc_bs == s.internal_bnd.size());
MatrixXd H = MatrixXd::Zero(s.component_sizes.size(), 2);
{
int hole_f = 0;
int hole_i = 0;
for (auto cs : s.component_sizes)
{
for (int i = 0; i < 3; i++)
H.row(hole_i) += m_uv.row(s.m_T(hole_f, i)); // redoing step 2
hole_f += cs;
hole_i++;
}
}
H /= 3.;
MatrixXd uv2;
igl::triangle::triangulate(V, E, H, std::basic_string<char>("qYYQ"), uv2, s.s_T);
auto bnd_n = s.internal_bnd.size();
for (auto i = 0; i < s.s_T.rows(); i++)
for (auto j = 0; j < s.s_T.cols(); j++)
{
auto &x = s.s_T(i, j);
if (x < bnd_n)
x = s.internal_bnd(x);
else
x += m_uv.rows() - bnd_n;
}
igl::cat(1, s.m_T, s.s_T, s.w_T);
s.w_uv.conservativeResize(m_uv.rows() - bnd_n + uv2.rows(), 2);
s.w_uv.bottomRows(uv2.rows() - bnd_n) = uv2.bottomRows(-bnd_n + uv2.rows());
update_scaffold(s);
// after_mesh_improve
compute_scaffold_gradient_matrix(s, s.Dx_s, s.Dy_s);
s.Dx_s.makeCompressed();
s.Dy_s.makeCompressed();
s.Dz_s.makeCompressed();
s.Ri_s = MatrixXd::Zero(s.Dx_s.rows(), s.dim * s.dim);
s.Ji_s.resize(s.Dx_s.rows(), s.dim * s.dim);
s.W_s.resize(s.Dx_s.rows(), s.dim * s.dim);
}
void add_new_patch(igl::SCAFData &s, const Eigen::MatrixXd &V_ref,
const Eigen::MatrixXi &F_ref,
const Eigen::RowVectorXd &center,
const Eigen::MatrixXd &uv_init)
{
using namespace std;
using namespace Eigen;
assert(uv_init.rows() != 0);
Eigen::VectorXd M;
igl::doublearea(V_ref, F_ref, M);
s.mesh_measure += M.sum() / 2;
Eigen::VectorXi bnd;
Eigen::MatrixXd bnd_uv;
std::vector<std::vector<int>> all_bnds;
igl::boundary_loop(F_ref, all_bnds);
int num_holes = all_bnds.size() - 1;
s.component_sizes.push_back(F_ref.rows());
MatrixXd m_uv = s.w_uv.topRows(s.mv_num);
igl::cat(1, m_uv, uv_init, s.w_uv);
s.m_M.conservativeResize(s.mf_num + M.size());
s.m_M.bottomRows(M.size()) = M / 2;
for (auto cur_bnd : all_bnds)
{
s.internal_bnd.conservativeResize(s.internal_bnd.size() + cur_bnd.size());
s.internal_bnd.bottomRows(cur_bnd.size()) = Map<ArrayXi>(cur_bnd.data(), cur_bnd.size()) + s.mv_num;
s.bnd_sizes.push_back(cur_bnd.size());
}
s.m_T.conservativeResize(s.mf_num + F_ref.rows(), 3);
s.m_T.bottomRows(F_ref.rows()) = F_ref.array() + s.mv_num;
s.mf_num += F_ref.rows();
s.m_V.conservativeResize(s.mv_num + V_ref.rows(), 3);
s.m_V.bottomRows(V_ref.rows()) = V_ref;
s.mv_num += V_ref.rows();
s.rect_frame_V = MatrixXd();
mesh_improve(s);
}
void compute_jacobians(SCAFData &s, const Eigen::MatrixXd &V_new, bool whole)
{
auto comp_J2 = [](const Eigen::MatrixXd &uv,
const Eigen::SparseMatrix<double> &Dx,
const Eigen::SparseMatrix<double> &Dy,
Eigen::MatrixXd &Ji) {
// Ji=[D1*u,D2*u,D1*v,D2*v];
Ji.resize(Dx.rows(), 4);
Ji.col(0) = Dx * uv.col(0);
Ji.col(1) = Dy * uv.col(0);
Ji.col(2) = Dx * uv.col(1);
Ji.col(3) = Dy * uv.col(1);
};
Eigen::MatrixXd m_V_new = V_new.topRows(s.mv_num);
comp_J2(m_V_new, s.Dx_m, s.Dy_m, s.Ji_m);
if (whole)
comp_J2(V_new, s.Dx_s, s.Dy_s, s.Ji_s);
}
double compute_energy_from_jacobians(const Eigen::MatrixXd &Ji,
const Eigen::VectorXd &areas,
igl::MappingEnergyType energy_type)
{
double energy = 0;
if (energy_type == igl::MappingEnergyType::SYMMETRIC_DIRICHLET)
energy = -4; // comply with paper description
return energy + igl::mapping_energy_with_jacobians(Ji, areas, energy_type, 0);
}
double compute_soft_constraint_energy(const SCAFData &s)
{
double e = 0;
for (auto const &x : s.soft_cons)
e += s.soft_const_p * (x.second - s.w_uv.row(x.first)).squaredNorm();
return e;
}
double compute_energy(SCAFData &s, Eigen::MatrixXd &w_uv, bool whole)
{
if (w_uv.rows() != s.v_num)
assert(!whole);
compute_jacobians(s, w_uv, whole);
double energy = compute_energy_from_jacobians(s.Ji_m, s.m_M, s.slim_energy);
if (whole)
energy += compute_energy_from_jacobians(s.Ji_s, s.s_M, s.scaf_energy);
energy += compute_soft_constraint_energy(s);
return energy;
}
void buildAm(const Eigen::VectorXd &sqrt_M,
const Eigen::SparseMatrix<double> &Dx,
const Eigen::SparseMatrix<double> &Dy,
const Eigen::MatrixXd &W,
Eigen::SparseMatrix<double> &Am)
{
std::vector<Eigen::Triplet<double>> IJV;
Eigen::SparseMatrix<double> Dz;
Eigen::SparseMatrix<double> MDx = sqrt_M.asDiagonal() * Dx;
Eigen::SparseMatrix<double> MDy = sqrt_M.asDiagonal() * Dy;
igl::slim_buildA(MDx, MDy, Dz, W, IJV);
Am.setFromTriplets(IJV.begin(), IJV.end());
Am.makeCompressed();
}
void buildRhs(const Eigen::VectorXd &sqrt_M,
const Eigen::MatrixXd &W,
const Eigen::MatrixXd &Ri,
Eigen::VectorXd &f_rhs)
{
const int dim = (W.cols() == 4) ? 2 : 3;
const int f_n = W.rows();
f_rhs.resize(dim * dim * f_n);
for (int i = 0; i < f_n; i++)
{
auto sqrt_area = sqrt_M(i);
f_rhs(i + 0 * f_n) = sqrt_area * (W(i, 0) * Ri(i, 0) + W(i, 1) * Ri(i, 1));
f_rhs(i + 1 * f_n) = sqrt_area * (W(i, 0) * Ri(i, 2) + W(i, 1) * Ri(i, 3));
f_rhs(i + 2 * f_n) = sqrt_area * (W(i, 2) * Ri(i, 0) + W(i, 3) * Ri(i, 1));
f_rhs(i + 3 * f_n) = sqrt_area * (W(i, 2) * Ri(i, 2) + W(i, 3) * Ri(i, 3));
}
}
void get_complement(const Eigen::VectorXi &bnd_ids, int v_n, Eigen::ArrayXi &unknown_ids)
{ // get the complement of bnd_ids.
int assign = 0, i = 0;
for (int get = 0; i < v_n && get < bnd_ids.size(); i++)
{
if (bnd_ids(get) == i)
get++;
else
unknown_ids(assign++) = i;
}
while (i < v_n)
unknown_ids(assign++) = i++;
assert(assign + bnd_ids.size() == v_n);
}
void build_surface_linear_system(const SCAFData &s, Eigen::SparseMatrix<double> &L, Eigen::VectorXd &rhs)
{
using namespace Eigen;
using namespace std;
const int v_n = s.v_num - (s.frame_ids.size());
const int dim = s.dim;
const int f_n = s.mf_num;
// to get the complete A
Eigen::VectorXd sqrtM = s.m_M.array().sqrt();
Eigen::SparseMatrix<double> A(dim * dim * f_n, dim * v_n);
auto decoy_Dx_m = s.Dx_m;
decoy_Dx_m.conservativeResize(s.W_m.rows(), v_n);
auto decoy_Dy_m = s.Dy_m;
decoy_Dy_m.conservativeResize(s.W_m.rows(), v_n);
buildAm(sqrtM, decoy_Dx_m, decoy_Dy_m, s.W_m, A);
const VectorXi &bnd_ids = s.fixed_ids;
auto bnd_n = bnd_ids.size();
if (bnd_n == 0)
{
Eigen::SparseMatrix<double> At = A.transpose();
At.makeCompressed();
Eigen::SparseMatrix<double> id_m(At.rows(), At.rows());
id_m.setIdentity();
L = At * A;
Eigen::VectorXd frhs;
buildRhs(sqrtM, s.W_m, s.Ri_m, frhs);
rhs = At * frhs;
}
else
{
MatrixXd bnd_pos;
igl::slice(s.w_uv, bnd_ids, 1, bnd_pos);
ArrayXi known_ids(bnd_ids.size() * dim);
ArrayXi unknown_ids((v_n - bnd_ids.rows()) * dim);
get_complement(bnd_ids, v_n, unknown_ids);
VectorXd known_pos(bnd_ids.size() * dim);
for (int d = 0; d < dim; d++)
{
auto n_b = bnd_ids.rows();
known_ids.segment(d * n_b, n_b) = bnd_ids.array() + d * v_n;
known_pos.segment(d * n_b, n_b) = bnd_pos.col(d);
unknown_ids.block(d * (v_n - n_b), 0, v_n - n_b, unknown_ids.cols()) =
unknown_ids.topRows(v_n - n_b) + d * v_n;
}
Eigen::SparseMatrix<double> Au, Ae;
igl::slice(A, unknown_ids, 2, Au);
igl::slice(A, known_ids, 2, Ae);
Eigen::SparseMatrix<double> Aut = Au.transpose();
Aut.makeCompressed();
L = Aut * Au;
Eigen::VectorXd frhs;
buildRhs(sqrtM, s.W_m, s.Ri_m, frhs);
rhs = Aut * (frhs - Ae * known_pos);
}
// add soft constraints.
for (auto const &x : s.soft_cons)
{
int v_idx = x.first;
for (int d = 0; d < dim; d++)
{
rhs(d * (v_n) + v_idx) += s.soft_const_p * x.second(d); // rhs
L.coeffRef(d * v_n + v_idx,
d * v_n + v_idx) += s.soft_const_p; // diagonal
}
}
}
void build_scaffold_linear_system(const SCAFData &s, Eigen::SparseMatrix<double> &L, Eigen::VectorXd &rhs)
{
using namespace Eigen;
const int f_n = s.W_s.rows();
const int v_n = s.Dx_s.cols();
const int dim = s.dim;
Eigen::VectorXd sqrtM = s.s_M.array().sqrt();
Eigen::SparseMatrix<double> A(dim * dim * f_n, dim * v_n);
buildAm(sqrtM, s.Dx_s, s.Dy_s, s.W_s, A);
VectorXi bnd_ids;
igl::cat(1, s.fixed_ids, s.frame_ids, bnd_ids);
auto bnd_n = bnd_ids.size();
assert(bnd_n > 0);
MatrixXd bnd_pos;
igl::slice(s.w_uv, bnd_ids, 1, bnd_pos);
ArrayXi known_ids(bnd_ids.size() * dim);
ArrayXi unknown_ids((v_n - bnd_ids.rows()) * dim);
get_complement(bnd_ids, v_n, unknown_ids);
VectorXd known_pos(bnd_ids.size() * dim);
for (int d = 0; d < dim; d++)
{
auto n_b = bnd_ids.rows();
known_ids.segment(d * n_b, n_b) = bnd_ids.array() + d * v_n;
known_pos.segment(d * n_b, n_b) = bnd_pos.col(d);
unknown_ids.block(d * (v_n - n_b), 0, v_n - n_b, unknown_ids.cols()) =
unknown_ids.topRows(v_n - n_b) + d * v_n;
}
Eigen::VectorXd sqrt_M = s.s_M.array().sqrt();
// manual slicing for A(:, unknown/known)'
Eigen::SparseMatrix<double> Au, Ae;
igl::slice(A, unknown_ids, 2, Au);
igl::slice(A, known_ids, 2, Ae);
Eigen::SparseMatrix<double> Aut = Au.transpose();
Aut.makeCompressed();
L = Aut * Au;
Eigen::VectorXd frhs;
buildRhs(sqrtM, s.W_s, s.Ri_s, frhs);
rhs = Aut * (frhs - Ae * known_pos);
}
void solve_weighted_arap(SCAFData &s, Eigen::MatrixXd &uv)
{
using namespace Eigen;
using namespace std;
int dim = s.dim;
igl::Timer timer;
timer.start();
VectorXi bnd_ids;
igl::cat(1, s.fixed_ids, s.frame_ids, bnd_ids);
const auto v_n = s.v_num;
const auto bnd_n = bnd_ids.size();
assert(bnd_n > 0);
MatrixXd bnd_pos;
igl::slice(s.w_uv, bnd_ids, 1, bnd_pos);
ArrayXi known_ids(bnd_n * dim);
ArrayXi unknown_ids((v_n - bnd_n) * dim);
get_complement(bnd_ids, v_n, unknown_ids);
VectorXd known_pos(bnd_ids.size() * dim);
for (int d = 0; d < dim; d++)
{
auto n_b = bnd_ids.rows();
known_ids.segment(d * n_b, n_b) = bnd_ids.array() + d * v_n;
known_pos.segment(d * n_b, n_b) = bnd_pos.col(d);
unknown_ids.block(d * (v_n - n_b), 0, v_n - n_b, unknown_ids.cols()) =
unknown_ids.topRows(v_n - n_b) + d * v_n;
}
Eigen::SparseMatrix<double> L;
Eigen::VectorXd rhs;
// fixed frame solving:
// x_e as the fixed frame, x_u for unknowns (mesh + unknown scaffold)
// min ||(A_u*x_u + A_e*x_e) - b||^2
// => A_u'*A_u*x_u = Au'* (b - A_e*x_e) := Au'* b_u
//
// separate matrix build:
// min ||A_m x_m - b_m||^2 + ||A_s x_all - b_s||^2 + soft + proximal
// First change dimension of A_m to fit for x_all
// (Not just at the end, since x_all is flattened along dimensions)
// L = A_m'*A_m + A_s'*A_s + soft + proximal
// rhs = A_m'* b_m + A_s' * b_s + soft + proximal
//
Eigen::SparseMatrix<double> L_m, L_s;
Eigen::VectorXd rhs_m, rhs_s;
build_surface_linear_system(s, L_m, rhs_m); // complete Am, with soft
build_scaffold_linear_system(s, L_s, rhs_s); // complete As, without proximal
L = L_m + L_s;
rhs = rhs_m + rhs_s;
L.makeCompressed();
Eigen::VectorXd unknown_Uc((v_n - s.frame_ids.size() - s.fixed_ids.size()) * dim), Uc(dim * v_n);
SimplicialLDLT<Eigen::SparseMatrix<double>> solver;
unknown_Uc = solver.compute(L).solve(rhs);
igl::slice_into(unknown_Uc, unknown_ids.matrix(), 1, Uc);
igl::slice_into(known_pos, known_ids.matrix(), 1, Uc);
uv = Map<Matrix<double, -1, -1, Eigen::ColMajor>>(Uc.data(), v_n, dim);
}
double perform_iteration(SCAFData &s)
{
Eigen::MatrixXd V_out = s.w_uv;
compute_jacobians(s, V_out, true);
igl::slim_update_weights_and_closest_rotations_with_jacobians(s.Ji_m, s.slim_energy, 0, s.W_m, s.Ri_m);
igl::slim_update_weights_and_closest_rotations_with_jacobians(s.Ji_s, s.scaf_energy, 0, s.W_s, s.Ri_s);
solve_weighted_arap(s, V_out);
auto whole_E = [&s](Eigen::MatrixXd &uv) { return compute_energy(s, uv, true); };
Eigen::MatrixXi w_T;
if (s.m_T.cols() == s.s_T.cols())
igl::cat(1, s.m_T, s.s_T, w_T);
else
w_T = s.s_T;
return igl::flip_avoiding_line_search(w_T, s.w_uv, V_out,
whole_E, -1) /
s.mesh_measure;
}
}
}
IGL_INLINE void igl::scaf_precompute(
const Eigen::MatrixXd &V,
const Eigen::MatrixXi &F,
const Eigen::MatrixXd &V_init,
igl::SCAFData &data,
igl::MappingEnergyType slim_energy,
Eigen::VectorXi &b,
Eigen::MatrixXd &bc,
double soft_p)
{
Eigen::MatrixXd CN;
Eigen::MatrixXi FN;
igl::scaf::add_new_patch(data, V, F, Eigen::RowVector2d(0, 0), V_init);
data.soft_const_p = soft_p;
for (int i = 0; i < b.rows(); i++)
data.soft_cons[b(i)] = bc.row(i);
data.slim_energy = slim_energy;
auto &s = data;
if (!data.has_pre_calc)
{
int v_n = s.mv_num + s.sv_num;
int f_n = s.mf_num + s.sf_num;
int dim = s.dim;
Eigen::MatrixXd F1, F2, F3;
igl::local_basis(s.m_V, s.m_T, F1, F2, F3);
auto face_proj = [](Eigen::MatrixXd& F){
std::vector<Eigen::Triplet<double> >IJV;
int f_num = F.rows();
for(int i=0; i<F.rows(); i++) {
IJV.push_back(Eigen::Triplet<double>(i, i, F(i,0)));
IJV.push_back(Eigen::Triplet<double>(i, i+f_num, F(i,1)));
IJV.push_back(Eigen::Triplet<double>(i, i+2*f_num, F(i,2)));
}
Eigen::SparseMatrix<double> P(f_num, 3*f_num);
P.setFromTriplets(IJV.begin(), IJV.end());
return P;
};
Eigen::SparseMatrix<double> G;
igl::grad(s.m_V, s.m_T, G);
s.Dx_m = face_proj(F1) * G;
s.Dy_m = face_proj(F2) * G;
igl::scaf::compute_scaffold_gradient_matrix(s, s.Dx_s, s.Dy_s);
s.Dx_m.makeCompressed();
s.Dy_m.makeCompressed();
s.Ri_m = Eigen::MatrixXd::Zero(s.Dx_m.rows(), dim * dim);
s.Ji_m.resize(s.Dx_m.rows(), dim * dim);
s.W_m.resize(s.Dx_m.rows(), dim * dim);
s.Dx_s.makeCompressed();
s.Dy_s.makeCompressed();
s.Ri_s = Eigen::MatrixXd::Zero(s.Dx_s.rows(), dim * dim);
s.Ji_s.resize(s.Dx_s.rows(), dim * dim);
s.W_s.resize(s.Dx_s.rows(), dim * dim);
data.has_pre_calc = true;
}
}
IGL_INLINE Eigen::MatrixXd igl::scaf_solve(SCAFData &s, int iter_num)
{
using namespace std;
using namespace Eigen;
s.energy = igl::scaf::compute_energy(s, s.w_uv, false) / s.mesh_measure;
for (int it = 0; it < iter_num; it++)
{
s.total_energy = igl::scaf::compute_energy(s, s.w_uv, true) / s.mesh_measure;
s.rect_frame_V = Eigen::MatrixXd();
igl::scaf::mesh_improve(s);
double new_weight = s.mesh_measure * s.energy / (s.sf_num * 100);
s.scaffold_factor = new_weight;
igl::scaf::update_scaffold(s);
s.total_energy = igl::scaf::perform_iteration(s);
s.energy =
igl::scaf::compute_energy(s, s.w_uv, false) / s.mesh_measure;
}
return s.w_uv.topRows(s.mv_num);
}
#ifdef IGL_STATIC_LIBRARY
#endif