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Sqrt3T.hh
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43
48 //=============================================================================
49 //
50 // CLASS Sqrt3T
51 //
52 //=============================================================================
53
54 #ifndef OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
55 #define OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
56
57
58 //== INCLUDES =================================================================
59
60 #include <OpenMesh/Core/Mesh/Handles.hh>
61 #include <OpenMesh/Core/System/config.hh>
62 #include <OpenMesh/Tools/Subdivider/Uniform/SubdividerT.hh>
63 #if defined(_DEBUG) || defined(DEBUG)
64 // Makes life lot easier, when playing/messing around with low-level topology
65 // changing methods of OpenMesh
66 # include <OpenMesh/Tools/Utils/MeshCheckerT.hh>
67 # define ASSERT_CONSISTENCY( T, m ) \
68 assert(OpenMesh::Utils::MeshCheckerT<T>(m).check())
69 #else
70 # define ASSERT_CONSISTENCY( T, m )
71 #endif
72 // -------------------- STL
73 #include <vector>
74 #if defined(OM_CC_MIPS)
75 # include <math.h>
76 #else
77 # include <cmath>
78 #endif
79
80
81 //== NAMESPACE ================================================================
82
83 namespace OpenMesh { // BEGIN_NS_OPENMESH
84 namespace Subdivider { // BEGIN_NS_DECIMATER
85 namespace Uniform { // BEGIN_NS_DECIMATER
86
87
88 //== CLASS DEFINITION =========================================================
89
90
97 template <typename MeshType, typename RealType = double>
98 class Sqrt3T : public SubdividerT< MeshType, RealType >
99 {
100 public:
101
102 typedef RealType real_t;
103 typedef MeshType mesh_t;
104 typedef SubdividerT< mesh_t, real_t > parent_t;
105
106 typedef std::pair< real_t, real_t > weight_t;
107 typedef std::vector< std::pair<real_t,real_t> > weights_t;
108
109 public:
110
111
112 Sqrt3T(void) : parent_t(), _1over3( real_t(1.0/3.0) ), _1over27( real_t(1.0/27.0) )
113 { init_weights(); }
114
115 Sqrt3T(MeshType &_m) : parent_t(_m), _1over3( real_t(1.0/3.0) ), _1over27( real_t(1.0/27.0) )
116 { init_weights(); }
117
118 virtual ~Sqrt3T() {}
119
120
121 public:
122
123
124 const char *name() const { return "Uniform Sqrt3"; }
125
126
128 void init_weights(size_t _max_valence=50)
129 {
130 weights_.resize(_max_valence);
131 std::generate(weights_.begin(), weights_.end(), compute_weight());
132 }
133
134
135 protected:
136
137
138 bool prepare( MeshType& _m )
139 {
140 _m.request_edge_status();
141 _m.add_property( vp_pos_ );
142 _m.add_property( ep_nv_ );
143 _m.add_property( mp_gen_ );
144 _m.property( mp_gen_ ) = 0;
145
146 return _m.has_edge_status() && vp_pos_.is_valid()
147 && ep_nv_.is_valid() && mp_gen_.is_valid();
148 }
149
150
151 bool cleanup( MeshType& _m )
152 {
153 _m.release_edge_status();
154 _m.remove_property( vp_pos_ );
155 _m.remove_property( ep_nv_ );
156 _m.remove_property( mp_gen_ );
157 return true;
158 }
159
160 bool subdivide( MeshType& _m, size_t _n , const bool _update_points = true)
161 {
162
164
165 typename MeshType::VertexIter vit;
166 typename MeshType::VertexVertexIter vvit;
167 typename MeshType::EdgeIter eit;
168 typename MeshType::FaceIter fit;
169 typename MeshType::FaceVertexIter fvit;
170 typename MeshType::VertexHandle vh;
171 typename MeshType::HalfedgeHandle heh;
172 typename MeshType::Point pos(0,0,0), zero(0,0,0);
173 size_t &gen = _m.property( mp_gen_ );
174
175 for (size_t l=0; l<_n; ++l)
176 {
177 // tag existing edges
178 for (eit=_m.edges_begin(); eit != _m.edges_end();++eit)
179 {
180 _m.status( *eit ).set_tagged( true );
181 if ( (gen%2) && _m.is_boundary(*eit) )
182 compute_new_boundary_points( _m, *eit ); // *) creates new vertices
183 }
184
185 // do relaxation of old vertices, but store new pos in property vp_pos_
186
187 for (vit=_m.vertices_begin(); vit!=_m.vertices_end(); ++vit)
188 {
189 if ( _m.is_boundary(*vit) )
190 {
191 if ( gen%2 )
192 {
193 heh = _m.halfedge_handle(*vit);
194 if (heh.is_valid()) // skip isolated newly inserted vertices *)
195 {
196 typename OpenMesh::HalfedgeHandle
197 prev_heh = _m.prev_halfedge_handle(heh);
198
199 assert( _m.is_boundary(heh ) );
200 assert( _m.is_boundary(prev_heh) );
201
202 pos = _m.point(_m.to_vertex_handle(heh));
203 pos += _m.point(_m.from_vertex_handle(prev_heh));
204 pos *= real_t(4.0);
205
206 pos += real_t(19.0) * _m.point( *vit );
207 pos *= _1over27;
208
209 _m.property( vp_pos_, *vit ) = pos;
210 }
211 }
212 else
213 _m.property( vp_pos_, *vit ) = _m.point( *vit );
214 }
215 else
216 {
217 size_t valence=0;
218
219 pos = zero;
220 for ( vvit = _m.vv_iter(*vit); vvit.is_valid(); ++vvit)
221 {
222 pos += _m.point( *vvit );
223 ++valence;
224 }
225 pos *= weights_[ valence ].second;
226 pos += weights_[ valence ].first * _m.point(*vit);
227 _m.property( vp_pos_, *vit ) = pos;
228 }
229 }
230
231 // insert new vertices, but store pos in vp_pos_
232 typename MeshType::FaceIter fend = _m.faces_end();
233 for (fit = _m.faces_begin();fit != fend; ++fit)
234 {
235 if ( (gen%2) && _m.is_boundary(*fit))
236 {
237 boundary_split( _m, *fit );
238 }
239 else
240 {
241 fvit = _m.fv_iter( *fit );
242 pos = _m.point( *fvit);
243 pos += _m.point(*(++fvit));
244 pos += _m.point(*(++fvit));
245 pos *= _1over3;
246 vh = _m.add_vertex( zero );
247 _m.property( vp_pos_, vh ) = pos;
248 _m.split( *fit, vh );
249 }
250 }
251
252 // commit new positions (now iterating over all vertices)
253 for (vit=_m.vertices_begin();vit != _m.vertices_end(); ++vit)
254 _m.set_point(*vit, _m.property( vp_pos_, *vit ) );
255
256 // flip old edges
257 for (eit=_m.edges_begin(); eit != _m.edges_end(); ++eit)
258 if ( _m.status( *eit ).tagged() && !_m.is_boundary( *eit ) )
259 _m.flip(*eit);
260
261 // Now we have an consistent mesh!
262 ASSERT_CONSISTENCY( MeshType, _m );
263
264 // increase generation by one
265 ++gen;
266 }
267 return true;
268 }
269
270 private:
271
274 struct compute_weight
275 {
276 compute_weight() : valence(-1) { }
277 weight_t operator() (void)
278 {
279 #if !defined(OM_CC_MIPS)
280 using std::cos;
281 #endif
282 if (++valence)
283 {
284 real_t alpha = real_t( (4.0-2.0*cos(2.0*M_PI / real_t(valence)) )/9.0 );
285 return weight_t( real_t(1)-alpha, alpha/real_t(valence) );
286 }
287 return weight_t(real_t(0.0), real_t(0.0) );
288 }
289 int valence;
290 };
291
292 private:
293
294 // Pre-compute location of new boundary points for odd generations
295 // and store them in the edge property ep_nv_;
296 void compute_new_boundary_points( MeshType& _m,
297 const typename MeshType::EdgeHandle& _eh)
298 {
299 assert( _m.is_boundary(_eh) );
300
301 typename MeshType::HalfedgeHandle heh;
302 typename MeshType::VertexHandle vh1, vh2, vh3, vh4, vhl, vhr;
303 typename MeshType::Point zero(0,0,0), P1, P2, P3, P4;
304
305 /*
306 // *---------*---------*
307 // / \ / \ / \
308 // / \ / \ / \
309 // / \ / \ / \
310 // / \ / \ / \
311 // *---------*--#---#--*---------*
312 //
313 // ^ ^ ^ ^ ^ ^
314 // P1 P2 pl pr P3 P4
315 */
316 // get halfedge pointing from P3 to P2 (outer boundary halfedge)
317
318 heh = _m.halfedge_handle(_eh,
319 _m.is_boundary(_m.halfedge_handle(_eh,1)));
320
321 assert( _m.is_boundary( _m.next_halfedge_handle( heh ) ) );
322 assert( _m.is_boundary( _m.prev_halfedge_handle( heh ) ) );
323
324 vh1 = _m.to_vertex_handle( _m.next_halfedge_handle( heh ) );
325 vh2 = _m.to_vertex_handle( heh );
326 vh3 = _m.from_vertex_handle( heh );
327 vh4 = _m.from_vertex_handle( _m.prev_halfedge_handle( heh ));
328
329 P1 = _m.point(vh1);
330 P2 = _m.point(vh2);
331 P3 = _m.point(vh3);
332 P4 = _m.point(vh4);
333
334 vhl = _m.add_vertex(zero);
335 vhr = _m.add_vertex(zero);
336
337 _m.property(vp_pos_, vhl ) = (P1 + real_t(16.0f) * P2 + real_t(10.0f) * P3) * _1over27;
338 _m.property(vp_pos_, vhr ) = ( real_t(10.0f) * P2 + real_t(16.0f) * P3 + P4) * _1over27;
339 _m.property(ep_nv_, _eh).first = vhl;
340 _m.property(ep_nv_, _eh).second = vhr;
341 }
342
343
344 void boundary_split( MeshType& _m, const typename MeshType::FaceHandle& _fh )
345 {
346 assert( _m.is_boundary(_fh) );
347
348 typename MeshType::VertexHandle vhl, vhr;
349 typename MeshType::FaceEdgeIter fe_it;
350 typename MeshType::HalfedgeHandle heh;
351
352 // find boundary edge
353 for( fe_it=_m.fe_iter( _fh ); fe_it.is_valid() && !_m.is_boundary( *fe_it ); ++fe_it ) {};
354
355 // use precomputed, already inserted but not linked vertices
356 vhl = _m.property(ep_nv_, *fe_it).first;
357 vhr = _m.property(ep_nv_, *fe_it).second;
358
359 /*
360 // *---------*---------*
361 // / \ / \ / \
362 // / \ / \ / \
363 // / \ / \ / \
364 // / \ / \ / \
365 // *---------*--#---#--*---------*
366 //
367 // ^ ^ ^ ^ ^ ^
368 // P1 P2 pl pr P3 P4
369 */
370 // get halfedge pointing from P2 to P3 (inner boundary halfedge)
371
372 heh = _m.halfedge_handle(*fe_it,
373 _m.is_boundary(_m.halfedge_handle(*fe_it,0)));
374
375 typename MeshType::HalfedgeHandle pl_P3;
376
377 // split P2->P3 (heh) in P2->pl (heh) and pl->P3
378 boundary_split( _m, heh, vhl ); // split edge
379 pl_P3 = _m.next_halfedge_handle( heh ); // store next halfedge handle
380 boundary_split( _m, heh ); // split face
381
382 // split pl->P3 in pl->pr and pr->P3
383 boundary_split( _m, pl_P3, vhr );
384 boundary_split( _m, pl_P3 );
385
386 assert( _m.is_boundary( vhl ) && _m.halfedge_handle(vhl).is_valid() );
387 assert( _m.is_boundary( vhr ) && _m.halfedge_handle(vhr).is_valid() );
388 }
389
390 void boundary_split(MeshType& _m,
391 const typename MeshType::HalfedgeHandle& _heh,
392 const typename MeshType::VertexHandle& _vh)
393 {
394 assert( _m.is_boundary( _m.edge_handle(_heh) ) );
395
396 typename MeshType::HalfedgeHandle
397 heh(_heh),
398 opp_heh( _m.opposite_halfedge_handle(_heh) ),
399 new_heh, opp_new_heh;
400 typename MeshType::VertexHandle to_vh(_m.to_vertex_handle(heh));
401 typename MeshType::HalfedgeHandle t_heh;
402
403 /*
404 * P5
405 * *
406 * /|\
407 * / \
408 * / \
409 * / \
410 * / \
411 * /_ heh new \
412 * *-----\*-----\*\-----*
413 * ^ ^ t_heh
414 * _vh to_vh
415 *
416 * P1 P2 P3 P4
417 */
418 // Re-Setting Handles
419
420 // find halfedge point from P4 to P3
421 for(t_heh = heh;
422 _m.next_halfedge_handle(t_heh) != opp_heh;
423 t_heh = _m.opposite_halfedge_handle(_m.next_halfedge_handle(t_heh)))
424 {}
425
426 assert( _m.is_boundary( t_heh ) );
427
428 new_heh = _m.new_edge( _vh, to_vh );
429 opp_new_heh = _m.opposite_halfedge_handle(new_heh);
430
431 // update halfedge connectivity
432
433 _m.set_next_halfedge_handle(t_heh, opp_new_heh); // P4-P3 -> P3-P2
434 // P2-P3 -> P3-P5
435 _m.set_next_halfedge_handle(new_heh, _m.next_halfedge_handle(heh));
436 _m.set_next_halfedge_handle(heh, new_heh); // P1-P2 -> P2-P3
437 _m.set_next_halfedge_handle(opp_new_heh, opp_heh); // P3-P2 -> P2-P1
438
439 // both opposite halfedges point to same face
440 _m.set_face_handle(opp_new_heh, _m.face_handle(opp_heh));
441
442 // let heh finally point to new inserted vertex
443 _m.set_vertex_handle(heh, _vh);
444
445 // let heh and new_heh point to same face
446 _m.set_face_handle(new_heh, _m.face_handle(heh));
447
448 // let opp_new_heh be the new outgoing halfedge for to_vh
449 // (replaces for opp_heh)
450 _m.set_halfedge_handle( to_vh, opp_new_heh );
451
452 // let opp_heh be the outgoing halfedge for _vh
453 _m.set_halfedge_handle( _vh, opp_heh );
454 }
455
456 void boundary_split( MeshType& _m,
457 const typename MeshType::HalfedgeHandle& _heh)
458 {
459 assert( _m.is_boundary( _m.opposite_halfedge_handle( _heh ) ) );
460
461 typename MeshType::HalfedgeHandle
462 heh(_heh),
463 n_heh(_m.next_halfedge_handle(heh));
464
465 typename MeshType::VertexHandle
466 to_vh(_m.to_vertex_handle(heh));
467
468 typename MeshType::HalfedgeHandle
469 heh2(_m.new_edge(to_vh,
470 _m.to_vertex_handle(_m.next_halfedge_handle(n_heh)))),
471 heh3(_m.opposite_halfedge_handle(heh2));
472
473 typename MeshType::FaceHandle
474 new_fh(_m.new_face()),
475 fh(_m.face_handle(heh));
476
477 // Relink (half)edges
478
479 #define set_next_heh set_next_halfedge_handle
480 #define next_heh next_halfedge_handle
481
482 _m.set_face_handle(heh, new_fh);
483 _m.set_face_handle(heh2, new_fh);
484 _m.set_next_heh(heh2, _m.next_heh(_m.next_heh(n_heh)));
485 _m.set_next_heh(heh, heh2);
486 _m.set_face_handle( _m.next_heh(heh2), new_fh);
487
488 // _m.set_face_handle( _m.next_heh(_m.next_heh(heh2)), new_fh);
489
490 _m.set_next_heh(heh3, n_heh);
491 _m.set_next_heh(_m.next_halfedge_handle(n_heh), heh3);
492 _m.set_face_handle(heh3, fh);
493 // _m.set_face_handle(n_heh, fh);
494
495 _m.set_halfedge_handle( fh, n_heh);
496 _m.set_halfedge_handle(new_fh, heh);
497
498 #undef set_next_halfedge_handle
499 #undef next_halfedge_handle
500
501 }
502
503 private:
504
505 weights_t weights_;
506 OpenMesh::VPropHandleT< typename MeshType::Point > vp_pos_;
507 OpenMesh::EPropHandleT< std::pair< typename MeshType::VertexHandle,
508 typename MeshType::VertexHandle> > ep_nv_;
509 OpenMesh::MPropHandleT< size_t > mp_gen_;
510
511 const real_t _1over3;
512 const real_t _1over27;
513 };
514
515
516 //=============================================================================
517 } // END_NS_UNIFORM
518 } // END_NS_SUBDIVIDER
519 } // END_NS_OPENMESH
520 //=============================================================================
521 #endif // OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
522 //=============================================================================
OpenMesh::HalfedgeHandle
Handle for a halfedge entity.
Definition: Handles.hh:127
OpenMesh::VPropHandleT< typename MeshType::Point >
OpenMesh::Subdivider::Uniform::Sqrt3T::prepare
bool prepare(MeshType &_m)
Prepare mesh, e.g. add properties.
Definition: Sqrt3T.hh:138
OpenMesh::Subdivider::Uniform::Sqrt3T::init_weights
void init_weights(size_t _max_valence=50)
Pre-compute weights.
Definition: Sqrt3T.hh:128
OpenMesh::Subdivider::Uniform::Sqrt3T::subdivide
bool subdivide(MeshType &_m, size_t _n, const bool _update_points=true)
Subdivide mesh _m _n times.
Definition: Sqrt3T.hh:160
OpenMesh::Subdivider::Uniform::Sqrt3T
Uniform Sqrt3 subdivision algorithm
Definition: Sqrt3T.hh:98
SubdividerT.hh
OpenMesh::Subdivider::Uniform::SubdividerT::operator()
bool operator()(MeshType &_m, size_t _n, const bool _update_points=true)
Subdivide the mesh _m _n times.
Definition: SubdividerT.hh:122
OpenMesh::Subdivider::Uniform::Sqrt3T::cleanup
bool cleanup(MeshType &_m)
Cleanup mesh after usage, e.g. remove added properties.
Definition: Sqrt3T.hh:151
OpenMesh
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:59
OpenMesh::EPropHandleT
Handle representing an edge property.
Definition: Property.hh:510
OpenMesh::Subdivider::Uniform::SubdividerT
Abstract base class for uniform subdivision algorithms.
Definition: SubdividerT.hh:88
OpenMesh::Subdivider::Uniform::Sqrt3T::name
const char * name() const
Return name of subdivision algorithm.
Definition: Sqrt3T.hh:124
OpenMesh::BaseHandle::is_valid
bool is_valid() const
The handle is valid iff the index is not negative.
Definition: Handles.hh:72
OpenMesh::MPropHandleT< size_t >