Files
create/src/Mod/MeshPart/App/MeshFlattening.cpp
2018-04-23 09:56:23 +02:00

256 lines
8.4 KiB
C++

/***************************************************************************
* Copyright (c) 2017 Lorenz Lechner *
* *
* This file is part of the FreeCAD CAx development system. *
* *
* This library is free software; you can redistribute it and/or *
* modify it under the terms of the GNU Library General Public *
* License as published by the Free Software Foundation; either *
* version 2 of the License, or (at your option) any later version. *
* *
* This library is distributed in the hope that it will be useful, *
* but WITHOUT ANY WARRANTY; without even the implied warranty of *
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
* GNU Library General Public License for more details. *
* *
* You should have received a copy of the GNU Library General Public *
* License along with this library; see the file COPYING.LIB. If not, *
* write to the Free Software Foundation, Inc., 59 Temple Place, *
* Suite 330, Boston, MA 02111-1307, USA *
* *
***************************************************************************/
#include "MeshFlattening.h"
#include "MeshFlatteningLscmRelax.h"
#include <Poly_Triangulation.hxx>
#include <BRep_Tool.hxx>
#include <Geom_Surface.hxx>
#include <Geom_BSplineSurface.hxx>
#include <set>
#include <map>
#include <vector>
#include <exception>
std::vector<ColMat<double, 3>> getBoundaries(ColMat<double, 3> vertices, ColMat<long, 3> tris)
{
// get a hashtable for all edges
// e: v1, v2, num
std::map<std::set<long>, std::vector<long>> hash_map;
std::vector<std::set<long>> hash_list;
std::map<long, std::vector<long>> neighbour_map;
std::vector<long> edge_vector_0;
std::vector<std::vector<long>> edge_vector;
for (long i=0; i<tris.rows(); i++)
{
for (long j=0; j<3; j++)
{
long k = j + 1;
if (k == 3)
k = 0;
long v1 = tris(i, j);
long v2 = tris(i, k);
std::set<long> hash {v1, v2};
hash_list.push_back(hash);
if (v1 < v2)
hash_map[hash] = std::vector<long>{v1, v2, 0};
else
hash_map[hash] = std::vector<long>{v2, v1, 0};
}
}
for (auto & hash: hash_list)
hash_map[hash][2] += 1;
for (auto &hash: hash_map)
{
if (hash.second[2] == 1)
{
long v0 = hash.second[0];
long v1 = hash.second[1];
neighbour_map[v0].push_back(v1);
neighbour_map[v1].push_back(v0);
}
}
while (neighbour_map.size() != 0)
{
long start_index = neighbour_map.begin()->first;
long close_index = start_index;
long next_index = neighbour_map[start_index][1];
long temporary_next;
edge_vector_0.clear();
edge_vector_0.push_back(close_index);
edge_vector_0.push_back(start_index);
neighbour_map.erase(start_index);
edge_vector_0.push_back(next_index);
while (next_index != close_index)
{
temporary_next = neighbour_map[next_index][0];
if (temporary_next != start_index)
{
start_index = next_index;
next_index = temporary_next;
}
else
{
start_index = next_index;
next_index = neighbour_map[start_index][1];
}
neighbour_map.erase(start_index);
edge_vector_0.push_back(next_index);
}
edge_vector.push_back(edge_vector_0);
}
std::vector<ColMat<double, 3>> edges;
for (auto &edge: edge_vector)
{
ColMat<double, 3> edge_vertices;
edge_vertices.resize(edge.size(), 3);
int i = 0;
for (auto index: edge)
{
edge_vertices.row(i) = vertices.row(index);
i++;
}
edges.push_back(edge_vertices);
}
return edges;
}
FaceUnwrapper::FaceUnwrapper(const TopoDS_Face& face)
{
long i = 0;
// transform to nurbs:
TopLoc_Location location;
// triangulate:
const Handle(Poly_Triangulation) &triangulation = BRep_Tool::Triangulation(face, location);
if (triangulation.IsNull())
throw std::runtime_error("null triangulation in face construction");
// compute uv coordinates
if (triangulation->HasUVNodes())
{
const TColgp_Array1OfPnt2d &_uv_nodes = triangulation->UVNodes();
this->uv_nodes.resize(triangulation->NbNodes(), 2);
i = 0;
for (gp_Pnt2d _uv_node: _uv_nodes)
{
this->uv_nodes.row(i) << _uv_node.X(), _uv_node.Y();
i++;
}
}
//
const TColgp_Array1OfPnt &_nodes = triangulation->Nodes();
this->xyz_nodes.resize(triangulation->NbNodes(), 3);
i = 0;
for (gp_Pnt _node: _nodes)
{
this->xyz_nodes.row(i) << _node.X(), _node.Y(), _node.Z();
i++;
}
const Poly_Array1OfTriangle &_tris = triangulation->Triangles();
this->tris.resize(triangulation->NbTriangles(), 3);
i = 0;
for (Poly_Triangle _tri: _tris)
{
int n1, n2, n3;
_tri.Get(n1, n2, n3);
this->tris.row(i) << n1-1, n2-1, n3-1;
i++;
}
}
void FaceUnwrapper::findFlatNodes(int steps, double val)
{
std::vector<long> fixed_pins; //TODO: INPUT
lscmrelax::LscmRelax mesh_flattener(this->xyz_nodes.transpose(), this->tris.transpose(), fixed_pins);
mesh_flattener.lscm();
for (int j=0; j<steps; j++)
mesh_flattener.relax(0.95);
this->ze_nodes = mesh_flattener.flat_vertices.transpose();
}
ColMat<double, 3> FaceUnwrapper::interpolateFlatFace(const TopoDS_Face& face)
{
if (this->uv_nodes.size() == 0)
throw(std::runtime_error("no uv-coordinates found, interpolating with nurbs is only possible if the Flattener was constructed with a nurbs."));
// extract xyz poles, knots, weights, degree
const Handle(Geom_Surface) &_surface = BRep_Tool::Surface(face);
const Handle(Geom_BSplineSurface) &_bspline = Handle(Geom_BSplineSurface)::DownCast(_surface);
const TColStd_Array1OfReal &_uknots = _bspline->UKnotSequence();
const TColStd_Array1OfReal &_vknots = _bspline->VKnotSequence();
Eigen::VectorXd weights;
weights.resize(_bspline->NbUPoles() * _bspline->NbVPoles());
long i = 0;
for (long u=1; u <= _bspline->NbUPoles(); u++)
{
for (long v=1; v <= _bspline->NbVPoles(); v++)
{
weights[i] = _bspline->Weight(u, v);
i++;
}
}
Eigen::VectorXd u_knots;
Eigen::VectorXd v_knots;
u_knots.resize(_uknots.Size());
v_knots.resize(_vknots.Size());
for (long u=1; u <= _uknots.Size(); u++)
{
u_knots[u - 1] = _uknots.Value(u);
}
for (long v=1; v <= _vknots.Size(); v++)
{
v_knots[v - 1] = _vknots.Value(v);
}
nu = nurbs::NurbsBase2D(u_knots, v_knots, weights, _bspline->UDegree(), _bspline->VDegree());
A = nu.getInfluenceMatrix(this->uv_nodes);
Eigen::LeastSquaresConjugateGradient<spMat > solver;
solver.compute(A);
ColMat<double, 2> ze_poles;
ColMat<double, 3> flat_poles;
ze_poles.resize(weights.rows(), 2);
flat_poles.resize(weights.rows(), 3);
flat_poles.setZero();
ze_poles = solver.solve(ze_nodes);
flat_poles.col(0) << ze_poles.col(0);
flat_poles.col(1) << ze_poles.col(1);
return flat_poles;
}
FaceUnwrapper::FaceUnwrapper(ColMat< double, int(3) > xyz_nodes, ColMat< long int, int(3) > tris)
{
this->tris = tris;
this->xyz_nodes = xyz_nodes;
}
std::vector<ColMat<double, 3>> FaceUnwrapper::getFlatBoundaryNodes()
{
if (this->ze_nodes.size() == 0)
throw(std::runtime_error("flat vertices not xet computed"));
ColMat<double, 3> flat_vertices;
flat_vertices.resize(this->ze_nodes.rows(), 3);
flat_vertices.setZero();
flat_vertices.col(0) << this->ze_nodes.col(0);
flat_vertices.col(1) << this->ze_nodes.col(1);
return getBoundaries(flat_vertices, this->tris);
}