Developer Documentation

PolyMeshT_impl.hh
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41
42
43
44
45 //=============================================================================
46 //
47 // CLASS PolyMeshT - IMPLEMENTATION
48 //
49 //=============================================================================
50
51
52 #define OPENMESH_POLYMESH_C
53
54
55 //== INCLUDES =================================================================
56
57 #include <OpenMesh/Core/Mesh/PolyMeshT.hh>
58 #include <OpenMesh/Core/Geometry/LoopSchemeMaskT.hh>
59 #include <OpenMesh/Core/Utils/GenProg.hh>
60 #include <OpenMesh/Core/Utils/vector_cast.hh>
61 #include <OpenMesh/Core/Utils/vector_traits.hh>
62 #include <OpenMesh/Core/System/omstream.hh>
63 #include <vector>
64
65
66 //== NAMESPACES ===============================================================
67
68
69 namespace OpenMesh {
70
71 //== IMPLEMENTATION ==========================================================
72
73 template <class Kernel>
74 uint PolyMeshT<Kernel>::find_feature_edges(Scalar _angle_tresh)
75 {
76 assert(Kernel::has_edge_status());//this function needs edge status property
77 uint n_feature_edges = 0;
78 for (EdgeIter e_it = Kernel::edges_begin(); e_it != Kernel::edges_end(); ++e_it)
79 {
80 if (fabs(calc_dihedral_angle(*e_it)) > _angle_tresh)
81 {//note: could be optimized by comparing cos(dih_angle) vs. cos(_angle_tresh)
82 this->status(*e_it).set_feature(true);
83 n_feature_edges++;
84 }
85 else
86 {
87 this->status(*e_it).set_feature(false);
88 }
89 }
90 return n_feature_edges;
91 }
92
93 //-----------------------------------------------------------------------------
94
95 template <class Kernel>
96 typename PolyMeshT<Kernel>::Normal
97 PolyMeshT<Kernel>::calc_face_normal(FaceHandle _fh) const
98 {
99 return calc_face_normal_impl(_fh, typename GenProg::IF<
100 vector_traits<PolyMeshT<Kernel>::Point>::size_ == 3,
101 PointIs3DTag,
102 PointIsNot3DTag
103 >::Result());
104 }
105
106 template <class Kernel>
107 typename PolyMeshT<Kernel>::Normal
108 PolyMeshT<Kernel>::calc_face_normal_impl(FaceHandle _fh, PointIs3DTag) const
109 {
110 assert(this->halfedge_handle(_fh).is_valid());
111 ConstFaceVertexIter fv_it(this->cfv_iter(_fh));
112
113 // Safeguard for 1-gons
114 if (!(++fv_it).is_valid()) return Normal(0, 0, 0);
115
116 // Safeguard for 2-gons
117 if (!(++fv_it).is_valid()) return Normal(0, 0, 0);
118
119 // use Newell's Method to compute the surface normal
120 Normal n(0,0,0);
121 for(fv_it = this->cfv_iter(_fh); fv_it.is_valid(); ++fv_it)
122 {
123 // next vertex
124 ConstFaceVertexIter fv_itn = fv_it;
125 ++fv_itn;
126
127 if (!fv_itn.is_valid())
128 fv_itn = this->cfv_iter(_fh);
129
130 // http://www.opengl.org/wiki/Calculating_a_Surface_Normal
131 const Point a = this->point(*fv_it) - this->point(*fv_itn);
132 const Point b = this->point(*fv_it) + this->point(*fv_itn);
133
134
135 // Due to traits, the value types of normals and points can be different.
136 // Therefore we cast them here.
137 n[0] += static_cast<typename vector_traits<Normal>::value_type>(a[1] * b[2]);
138 n[1] += static_cast<typename vector_traits<Normal>::value_type>(a[2] * b[0]);
139 n[2] += static_cast<typename vector_traits<Normal>::value_type>(a[0] * b[1]);
140 }
141
142 const typename vector_traits<Normal>::value_type length = norm(n);
143
144 // The expression ((n *= (1.0/norm)),n) is used because the OpenSG
145 // vector class does not return self after component-wise
146 // self-multiplication with a scalar!!!
147 return (length != typename vector_traits<Normal>::value_type(0))
148 ? ((n *= (typename vector_traits<Normal>::value_type(1)/length)), n)
149 : Normal(0, 0, 0);
150 }
151
152 template <class Kernel>
153 typename PolyMeshT<Kernel>::Normal
154 PolyMeshT<Kernel>::calc_face_normal_impl(FaceHandle, PointIsNot3DTag) const
155 {
156 // Dummy fallback implementation
157 // Returns just an initialized all 0 normal
158 // This function is only used if we don't hate a matching implementation
159 // for normal computation with the current vector type defined in the mesh traits
160
161 assert(false);
162
163 Normal normal;
164 vectorize(normal,0);
165 return normal;
166 }
167
168 //-----------------------------------------------------------------------------
169
170 template <class Kernel>
171 typename PolyMeshT<Kernel>::Normal
172 PolyMeshT<Kernel>::
173 calc_face_normal(const Point& _p0,
174 const Point& _p1,
175 const Point& _p2) const
176 {
177 return calc_face_normal_impl(_p0, _p1, _p2, typename GenProg::IF<
178 vector_traits<PolyMeshT<Kernel>::Point>::size_ == 3,
179 PointIs3DTag,
180 PointIsNot3DTag
181 >::Result());
182 }
183
184 template <class Kernel>
185 typename PolyMeshT<Kernel>::Normal
186 PolyMeshT<Kernel>::
187 calc_face_normal_impl(const Point& _p0,
188 const Point& _p1,
189 const Point& _p2,
190 PointIs3DTag) const
191 {
192 #if 1
193 // The OpenSG <Vector>::operator -= () does not support the type Point
194 // as rhs. Therefore use vector_cast at this point!!!
195 // Note! OpenSG distinguishes between Normal and Point!!!
196 Normal p1p0(vector_cast<Normal>(_p0)); p1p0 -= vector_cast<Normal>(_p1);
197 Normal p1p2(vector_cast<Normal>(_p2)); p1p2 -= vector_cast<Normal>(_p1);
198
199 Normal n = cross(p1p2, p1p0);
200 typename vector_traits<Normal>::value_type length = norm(n);
201
202 // The expression ((n *= (1.0/norm)),n) is used because the OpenSG
203 // vector class does not return self after component-wise
204 // self-multiplication with a scalar!!!
205 return (length != typename vector_traits<Normal>::value_type(0))
206 ? ((n *= (typename vector_traits<Normal>::value_type(1)/length)),n)
207 : Normal(0,0,0);
208 #else
209 Point p1p0 = _p0; p1p0 -= _p1;
210 Point p1p2 = _p2; p1p2 -= _p1;
211
212 Normal n = vector_cast<Normal>(cross(p1p2, p1p0));
213 typename vector_traits<Normal>::value_type length = norm(n);
214
215 return (length != 0.0) ? n *= (1.0/length) : Normal(0,0,0);
216 #endif
217 }
218
219 template <class Kernel>
220 typename PolyMeshT<Kernel>::Normal
221 PolyMeshT<Kernel>::calc_face_normal_impl(const Point&, const Point&, const Point&, PointIsNot3DTag) const
222 {
223
224 // Dummy fallback implementation
225 // Returns just an initialized all 0 normal
226 // This function is only used if we don't hate a matching implementation
227 // for normal computation with the current vector type defined in the mesh traits
228
229 assert(false);
230
231 Normal normal;
232 vectorize(normal,0);
233 return normal;
234 }
235
236 //-----------------------------------------------------------------------------
237
238 template <class Kernel>
239 typename PolyMeshT<Kernel>::Point
240 PolyMeshT<Kernel>::
241 calc_face_centroid(FaceHandle _fh) const
242 {
243 Point _pt;
244 vectorize(_pt, 0);
245 Scalar valence = 0.0;
246 for (ConstFaceVertexIter cfv_it = this->cfv_iter(_fh); cfv_it.is_valid(); ++cfv_it, valence += 1.0)
247 {
248 _pt += this->point(*cfv_it);
249 }
250 _pt /= valence;
251 return _pt;
252 }
253 //-----------------------------------------------------------------------------
254
255
256 template <class Kernel>
257 void
258 PolyMeshT<Kernel>::
259 update_normals()
260 {
261 // Face normals are required to compute the vertex and the halfedge normals
262 if (Kernel::has_face_normals() ) {
263 update_face_normals();
264
265 if (Kernel::has_vertex_normals() ) update_vertex_normals();
266 if (Kernel::has_halfedge_normals()) update_halfedge_normals();
267 }
268 }
269
270
271 //-----------------------------------------------------------------------------
272
273
274 template <class Kernel>
275 void
276 PolyMeshT<Kernel>::
277 update_face_normals()
278 {
279 FaceIter f_it(Kernel::faces_sbegin()), f_end(Kernel::faces_end());
280
281 for (; f_it != f_end; ++f_it)
282 this->set_normal(*f_it, calc_face_normal(*f_it));
283 }
284
285
286 //-----------------------------------------------------------------------------
287
288
289 template <class Kernel>
290 void
291 PolyMeshT<Kernel>::
292 update_halfedge_normals(const double _feature_angle)
293 {
294 HalfedgeIter h_it(Kernel::halfedges_begin()), h_end(Kernel::halfedges_end());
295
296 for (; h_it != h_end; ++h_it)
297 this->set_normal(*h_it, calc_halfedge_normal(*h_it, _feature_angle));
298 }
299
300
301 //-----------------------------------------------------------------------------
302
303
304 template <class Kernel>
305 typename PolyMeshT<Kernel>::Normal
306 PolyMeshT<Kernel>::
307 calc_halfedge_normal(HalfedgeHandle _heh, const double _feature_angle) const
308 {
309 if(Kernel::is_boundary(_heh))
310 return Normal(0,0,0);
311 else
312 {
313 std::vector<FaceHandle> fhs; fhs.reserve(10);
314
315 HalfedgeHandle heh = _heh;
316
317 // collect CW face-handles
318 do
319 {
320 fhs.push_back(Kernel::face_handle(heh));
321
322 heh = Kernel::next_halfedge_handle(heh);
323 heh = Kernel::opposite_halfedge_handle(heh);
324 }
325 while(heh != _heh && !Kernel::is_boundary(heh) && !is_estimated_feature_edge(heh, _feature_angle));
326
327 // collect CCW face-handles
328 if(heh != _heh && !is_estimated_feature_edge(_heh, _feature_angle))
329 {
330 heh = Kernel::opposite_halfedge_handle(_heh);
331
332 if ( !Kernel::is_boundary(heh) ) {
333 do
334 {
335
336 fhs.push_back(Kernel::face_handle(heh));
337
338 heh = Kernel::prev_halfedge_handle(heh);
339 heh = Kernel::opposite_halfedge_handle(heh);
340 }
341 while(!Kernel::is_boundary(heh) && !is_estimated_feature_edge(heh, _feature_angle));
342 }
343 }
344
345 Normal n(0,0,0);
346 for(unsigned int i=0; i<fhs.size(); ++i)
347 n += Kernel::normal(fhs[i]);
348
349 return normalize(n);
350 }
351 }
352
353
354 //-----------------------------------------------------------------------------
355
356
357 template <class Kernel>
358 bool
359 PolyMeshT<Kernel>::
360 is_estimated_feature_edge(HalfedgeHandle _heh, const double _feature_angle) const
361 {
362 EdgeHandle eh = Kernel::edge_handle(_heh);
363
364 if(Kernel::has_edge_status())
365 {
366 if(Kernel::status(eh).feature())
367 return true;
368 }
369
370 if(Kernel::is_boundary(eh))
371 return false;
372
373 // compute angle between faces
374 FaceHandle fh0 = Kernel::face_handle(_heh);
375 FaceHandle fh1 = Kernel::face_handle(Kernel::opposite_halfedge_handle(_heh));
376
377 Normal fn0 = Kernel::normal(fh0);
378 Normal fn1 = Kernel::normal(fh1);
379
380 // dihedral angle above angle threshold
381 return ( dot(fn0,fn1) < cos(_feature_angle) );
382 }
383
384
385 //-----------------------------------------------------------------------------
386
387
388 template <class Kernel>
389 typename PolyMeshT<Kernel>::Normal
390 PolyMeshT<Kernel>::
391 calc_vertex_normal(VertexHandle _vh) const
392 {
393 Normal n;
394 calc_vertex_normal_fast(_vh,n);
395
396 Scalar length = norm(n);
397 if (length != 0.0) n *= (Scalar(1.0)/length);
398
399 return n;
400 }
401
402 //-----------------------------------------------------------------------------
403 template <class Kernel>
404 void PolyMeshT<Kernel>::
405 calc_vertex_normal_fast(VertexHandle _vh, Normal& _n) const
406 {
407 vectorize(_n, 0.0);
408 for (ConstVertexFaceIter vf_it = this->cvf_iter(_vh); vf_it.is_valid(); ++vf_it)
409 _n += this->normal(*vf_it);
410 }
411
412 //-----------------------------------------------------------------------------
413 template <class Kernel>
414 void PolyMeshT<Kernel>::
415 calc_vertex_normal_correct(VertexHandle _vh, Normal& _n) const
416 {
417 vectorize(_n, 0.0);
418 ConstVertexIHalfedgeIter cvih_it = this->cvih_iter(_vh);
419 if (! cvih_it.is_valid() )
420 {//don't crash on isolated vertices
421 return;
422 }
423 Normal in_he_vec;
424 calc_edge_vector(*cvih_it, in_he_vec);
425 for ( ; cvih_it.is_valid(); ++cvih_it)
426 {//calculates the sector normal defined by cvih_it and adds it to _n
427 if (this->is_boundary(*cvih_it))
428 {
429 continue;
430 }
431 HalfedgeHandle out_heh(this->next_halfedge_handle(*cvih_it));
432 Normal out_he_vec;
433 calc_edge_vector(out_heh, out_he_vec);
434 _n += cross(in_he_vec, out_he_vec);//sector area is taken into account
435 in_he_vec = out_he_vec;
436 in_he_vec *= -1;//change the orientation
437 }
438 }
439
440 //-----------------------------------------------------------------------------
441 template <class Kernel>
442 void PolyMeshT<Kernel>::
443 calc_vertex_normal_loop(VertexHandle _vh, Normal& _n) const
444 {
445 static const LoopSchemeMaskDouble& loop_scheme_mask__ =
446 LoopSchemeMaskDoubleSingleton::Instance();
447
448 Normal t_v(0.0,0.0,0.0), t_w(0.0,0.0,0.0);
449 unsigned int vh_val = this->valence(_vh);
450 unsigned int i = 0;
451 for (ConstVertexOHalfedgeIter cvoh_it = this->cvoh_iter(_vh); cvoh_it.is_valid(); ++cvoh_it, ++i)
452 {
453 VertexHandle r1_v( this->to_vertex_handle(*cvoh_it) );
454 t_v += (typename vector_traits<Point>::value_type)(loop_scheme_mask__.tang0_weight(vh_val, i))*this->point(r1_v);
455 t_w += (typename vector_traits<Point>::value_type)(loop_scheme_mask__.tang1_weight(vh_val, i))*this->point(r1_v);
456 }
457 _n = cross(t_w, t_v);//hack: should be cross(t_v, t_w), but then the normals are reversed?
458 }
459
460 //-----------------------------------------------------------------------------
461
462
463 template <class Kernel>
464 void
465 PolyMeshT<Kernel>::
466 update_vertex_normals()
467 {
468 VertexIter v_it(Kernel::vertices_begin()), v_end(Kernel::vertices_end());
469
470 for (; v_it!=v_end; ++v_it)
471 this->set_normal(*v_it, calc_vertex_normal(*v_it));
472 }
473
474 //=============================================================================
475 } // namespace OpenMesh
476 //=============================================================================
OpenMesh::PolyMeshT::calc_face_normal
virtual Normal calc_face_normal(FaceHandle _fh) const
Definition: PolyMeshT_impl.hh:97
OpenMesh::vector_cast
void vector_cast(const src_t &_src, dst_t &_dst, GenProg::Int2Type< n >)
Cast vector type to another vector type by copying the vector elements.
Definition: vector_cast.hh:81
OpenMesh::PolyMeshT::calc_vertex_normal_loop
void calc_vertex_normal_loop(VertexHandle _vh, Normal &_n) const
Compute normals for all primitives.
Definition: PolyMeshT_impl.hh:443
OpenMesh::PolyMeshT::PointIsNot3DTag
Definition: PolyMeshT.hh:574
OpenMesh::PolyMeshT::ConstFaceVertexIter
Kernel::ConstFaceVertexIter ConstFaceVertexIter
Circulator.
Definition: PolyMeshT.hh:177
OpenMesh::PolyMeshT::Point
Kernel::Point Point
Coordinate type.
Definition: PolyMeshT.hh:112
OpenMesh::cross
osg::Vec3f cross(const osg::Vec3f &_v1, const osg::Vec3f &_v2)
Adapter for osg vector member computing a scalar product.
Definition: VectorAdapter.hh:191
OpenMesh::PolyMeshT::Scalar
Kernel::Scalar Scalar
Scalar type.
Definition: PolyMeshT.hh:110
OpenMesh::PolyMeshT::calc_face_centroid
void calc_face_centroid(FaceHandle _fh, Point &_pt) const
calculates the average of the vertices defining _fh
Definition: PolyMeshT.hh:275
OpenMesh::PolyMeshT::ConstVertexFaceIter
Kernel::ConstVertexFaceIter ConstVertexFaceIter
Circulator.
Definition: PolyMeshT.hh:176
OpenMesh::dot
osg::Vec3f::ValueType dot(const osg::Vec3f &_v1, const osg::Vec3f &_v2)
Adapter for osg vector member computing a scalar product.
Definition: VectorAdapter.hh:176
OpenMesh::PolyMeshT::VertexHandle
Kernel::VertexHandle VertexHandle
Handle for referencing the corresponding item.
Definition: PolyMeshT.hh:136
OpenMesh::LoopSchemeMaskT
Definition: LoopSchemeMaskT.hh:66
OpenMesh::PolyMeshT::update_vertex_normals
void update_vertex_normals()
Update normal vectors for all vertices.
Definition: PolyMeshT_impl.hh:466
OpenMesh::PolyMeshT::calc_vertex_normal_correct
void calc_vertex_normal_correct(VertexHandle _vh, Normal &_n) const
Compute normals for all primitives.
Definition: PolyMeshT_impl.hh:415
OpenMesh::PolyMeshT::Normal
Kernel::Normal Normal
Normal type.
Definition: PolyMeshT.hh:114
OpenMesh::SingletonT::Instance
static T & Instance()
Definition: SingletonT.hh:89
OpenMesh::PolyMeshT::find_feature_edges
unsigned int find_feature_edges(Scalar _angle_tresh=OpenMesh::deg_to_rad(44.0))
Definition: PolyMeshT_impl.hh:74
OpenMesh::PolyMeshT::update_halfedge_normals
void update_halfedge_normals(const double _feature_angle=0.8)
Update normal vectors for all halfedges.
Definition: PolyMeshT_impl.hh:292
OpenMesh::PolyMeshT::ConstVertexIHalfedgeIter
Kernel::ConstVertexIHalfedgeIter ConstVertexIHalfedgeIter
Circulator.
Definition: PolyMeshT.hh:174
OpenMesh::PolyMeshT::is_estimated_feature_edge
bool is_estimated_feature_edge(HalfedgeHandle _heh, const double _feature_angle) const
Definition: PolyMeshT_impl.hh:360
OpenMesh::PolyMeshT::PointIs3DTag
Definition: PolyMeshT.hh:573
OpenMesh::vector_traits
Definition: vector_traits.hh:88
OpenMesh::PolyMeshT::ConstVertexOHalfedgeIter
Kernel::ConstVertexOHalfedgeIter ConstVertexOHalfedgeIter
Circulator.
Definition: PolyMeshT.hh:173
OpenMesh::PolyMeshT::update_face_normals
void update_face_normals()
Update normal vectors for all faces.
Definition: PolyMeshT_impl.hh:277
OpenMesh::vector_traits::value_type
T::value_type value_type
Type of the scalar value.
Definition: vector_traits.hh:94
OpenMesh::PolyMeshT::calc_halfedge_normal
virtual Normal calc_halfedge_normal(HalfedgeHandle _heh, const double _feature_angle=0.8) const
Calculate halfedge normal for one specific halfedge.
Definition: PolyMeshT_impl.hh:307
OpenMesh::PolyMeshT::calc_vertex_normal
Normal calc_vertex_normal(VertexHandle _vh) const
Calculate vertex normal for one specific vertex.
Definition: PolyMeshT_impl.hh:391
OpenMesh
Definition: MeshItems.hh:59
omstream.hh
OpenMesh::PolyMeshT::update_normals
void update_normals()
Compute normals for all primitives.
Definition: PolyMeshT_impl.hh:259
OpenMesh::PolyMeshT::calc_vertex_normal_fast
void calc_vertex_normal_fast(VertexHandle _vh, Normal &_n) const
Definition: PolyMeshT_impl.hh:405
OpenMesh::PolyMeshT
Definition: PolyMeshT.hh:90