1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
|
/****************************************************************************
* VCGLib o o *
* Visual and Computer Graphics Library o o *
* _ O _ *
* Copyright(C) 2004 \/)\/ *
* Visual Computing Lab /\/| *
* ISTI - Italian National Research Council | *
* \ *
* All rights reserved. *
* *
* This program is free software; you can redistribute it and/or modify *
* it under the terms of the GNU General Public License as published by *
* the Free Software Foundation; either version 2 of the License, or *
* (at your option) any later version. *
* *
* This program 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 General Public License (http://www.gnu.org/licenses/gpl.txt) *
* for more details. *
* *
****************************************************************************/
#ifndef __VCGLIB_POLYGON_SUPPORT
#define __VCGLIB_POLYGON_SUPPORT
#include <vector>
#include <vcg/complex/algorithms/subset.h>
#include <vcg/simplex/face/jumping_pos.h>
#include <vcg/space/planar_polygon_tessellation.h>
namespace vcg {
namespace tri {
/// \ingroup trimesh
/// \headerfile polygon_support.h vcg/complex/algorithms/polygon_support.h
/// \brief This class is used convert between polygonal meshes and triangular meshes
/**
This class contains two members that allow to build a triangular mesh from a polygonal mesh
and viceversa. In a trimesh, the generic polygons with n sides are codified represented by tagging the internal edge of the face
with the SetF.
*/
template <class TriMeshType,class PolyMeshType >
struct PolygonSupport{
/**
Given a tri mesh (with per-face normals and FF connectivity),
merges flat faces into larger polygons.
**/
static void MergeFlatFaces(TriMeshType & tm, double tolerance = 0.1E-4){
typedef typename TriMeshType::CoordType::ScalarType Scalar;
typedef typename TriMeshType::FaceIterator FaceIterator;
typedef typename TriMeshType::FaceType FaceType;
Scalar minDist = 1 - Scalar(tolerance);
for (FaceIterator fi=tm.face.begin(); fi!=tm.face.end(); fi++) {
FaceType *fa = &*fi;
for (int w=0; w<3; w++) {
FaceType *fb = fa->FFp(w);
if ( (fb>fa) && (fa->N()*fb->N() > minDist) ) {
fa->SetF( w );
fb->SetF( fa->FFi(w) ); // reciprocate
}
}
}
}
/**
Import a trianglemesh from a polygon mesh
**/
static void ImportFromPolyMesh(TriMeshType & tm, PolyMeshType & pm){
std::vector<typename PolyMeshType::CoordType> points;
std::vector<int> faces;
// the vertices are the same, simply import them
typename PolyMeshType::VertexIterator vi;
typename TriMeshType::FaceIterator tfi,tfib ;
typename TriMeshType ::VertexIterator tvi = Allocator<TriMeshType>::AddVertices(tm,pm.vert.size());
int cnt = 0;
for(tvi = tm.vert.begin(),vi = pm.vert.begin(); tvi != tm.vert.end(); ++tvi,++vi,++cnt)
if(!(*vi).IsD()) (*tvi).ImportData(*vi); else vcg::tri::Allocator<TriMeshType>::DeleteVertex(tm,(*tvi));
typename PolyMeshType::FaceIterator fi;
for(fi = pm.face.begin(); fi != pm.face.end(); ++fi)
if(!((*fi).IsD())){
points.clear();
for(int i = 0; i < (*fi).VN(); ++i) {
typename PolyMeshType::VertexType * v = (*fi).V(i);
points.push_back(v->P());
}
faces.clear();
TessellatePlanarPolygon3(points,faces);
tfib = tfi = Allocator<TriMeshType>::AddFaces(tm,faces.size()/3);
for(int i = 0; tfi != tm.face.end();++tfi){
(*tfi).V(0) = &tm.vert[ (*fi).V( faces[i] ) - &(*pm.vert.begin())];
(*tfi).V(1) = &tm.vert[ (*fi).V( faces[i+1]) - &(*pm.vert.begin())];
(*tfi).V(2) = &tm.vert[ (*fi).V( faces[i+2]) - &(*pm.vert.begin())];
// set the F flags
if( (faces[i]+1)%points.size() != faces[i+1]) (*tfi).SetF(0);
if( (faces[i+1]+1)%points.size() != faces[i+2]) (*tfi).SetF(1);
if( (faces[i+2]+1)%points.size() != faces[i]) (*tfi).SetF(2);
i+=3;
}
}
}
/**
Import a polygon mesh from a triangle mesh
**/
static void ImportFromTriMesh( PolyMeshType & pm, TriMeshType & tm){
// the vertices are the same, simply import them
int cnt = 0;
typename TriMeshType ::ConstVertexIterator tvi;
typename PolyMeshType::VertexIterator vi = vcg::tri::Allocator<PolyMeshType>::AddVertices(pm,tm.vert.size());
for(tvi = tm.vert.begin(); tvi != tm.vert.end(); ++tvi,++vi,++cnt)
if(!(*tvi).IsD())(*vi).ImportData(*tvi); else vcg::tri::Allocator<PolyMeshType> ::DeleteVertex(pm,(*vi));
// convert the faces
typename TriMeshType::FaceIterator tfi;
vcg::face::JumpingPos<typename TriMeshType::FaceType> p;
for( tfi = tm.face.begin(); tfi != tm.face.end(); ++tfi) if(!(*tfi).IsD() && !(*tfi).IsV())
{
std::vector<typename TriMeshType::VertexPointer> vs;// vertices of the polygon
std::vector<typename TriMeshType::FacePointer> fs;// triangle faces corresponding to the polygon
// find a non tagged edge
int se = 0;
for(;se < 3;++se) if (!(*tfi).IsF(se)) break;
// initialize a pos on the first non tagged edge
typename TriMeshType::VertexPointer v0 = (*tfi).V(se);
p.F() = &(*tfi);
p.E() = se;
p.V() = p.F()->V(p.F()->Next(se));
p.FlipE();
vs.push_back(p.F()->V(se));
do{
while(p.F()->IsF(p.E())) { fs.push_back(p.F()); p.FlipF(); p.FlipE(); p.F()->SetV();}
vs.push_back(p.F()->V(p.E()));
p.FlipV();
p.FlipE();
} while( p.V() != v0 );
//now vs contains all the vertices of the polygon (still in the trimesh)
typename PolyMeshType::FaceIterator pfi = vcg::tri::Allocator<PolyMeshType>::AddFaces(pm,1);
(*pfi).Alloc(vs.size());
for( int i = 0 ; i < vs.size(); ++i)
(*pfi).V(i) = ( typename PolyMeshType::VertexType*) & pm.vert[vs[i]-&(*tm.vert.begin())];
// here handle the other compoenents of the face (how the conponents of the n triangle faces goes in the
// the property of the polygon (e.g. the normal, the color, the quality and so on)
// TODO
}
}
// Given a facepointer, it build a vector with all the vertex pointer
// around the polygonal face determined by the current FAUX-EDGE markings
// It assumes that the mesh is 2Manifold and has FF adjacency already computed
// NOTE: All the faces touched are marked as visited. (so for example you can avoid to get twice the same polygon)
static void ExtractPolygon(typename TriMeshType::FacePointer tfp, std::vector<typename TriMeshType::VertexPointer> &vs)
{
vs.clear();
// find a non tagged edge
int se = -1;
for(int i=0; i<3; i++) if (!( tfp->IsF(i))) { se = i; break;}
// all faux edges return an empty vertex vector!
if(se==-1) return;
// initialize a pos on the first non faux edge
typename TriMeshType::VertexPointer v0 = tfp->V(se);
vcg::face::Pos<typename TriMeshType::FaceType> p(tfp,se,v0);
vcg::face::Pos<typename TriMeshType::FaceType> start(p);
do
{
assert(!p.F()->IsF(p.E()));
vs.push_back(p.F()->V(p.E()));
p.FlipE();
while( p.F()->IsF(p.E()) )
{
p.F()->SetV();
p.FlipF();
p.FlipE();
}
p.FlipV();
} while(p!=start);
}
}; // end of struct
}} // end namespace vcg::tri
#endif // __VCGLIB_TRI_CLIP
|
