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ModRoundnessT.hh
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43 
48 //=============================================================================
49 //
50 // CLASS ModRoundnessT
51 //
52 //=============================================================================
53 
54 #ifndef OPENMESH_DECIMATER_MODROUNDNESST_HH
55 #define OPENMESH_DECIMATER_MODROUNDNESST_HH
56 
57 
58 //== INCLUDES =================================================================
59 
61 #include <math.h>
62 
63 #if defined(OM_CC_MSVC)
64 # define OM_ENABLE_WARNINGS 4244
65 # pragma warning(disable : OM_ENABLE_WARNINGS )
66 #endif
67 
68 //== NAMESPACE ================================================================
69 
70 namespace OpenMesh { // BEGIN_NS_OPENMESH
71 namespace Decimater { // BEGIN_NS_DECIMATER
72 
73 
74 //== CLASS DEFINITION =========================================================
75 
76 
85 template <class MeshT>
86 class ModRoundnessT : public ModBaseT<MeshT>
87 {
88  public:
89  DECIMATING_MODULE( ModRoundnessT, MeshT, Roundness );
90 
91  public:
92 
93  // typedefs
94  typedef typename MeshT::Point Point;
95  typedef typename vector_traits<Point>::value_type value_type;
96 
97  public:
98 
100  ModRoundnessT( MeshT &_dec ) :
101  Base(_dec, false),
102  min_r_(-1.0)
103  { }
104 
107 
108  public: // inherited
109 
120  float collapse_priority(const CollapseInfo& _ci)
121  {
122  // using namespace OpenMesh;
123 
124  typename Mesh::ConstVertexOHalfedgeIter voh_it(Base::mesh(), _ci.v0);
125  double r;
126  double priority = 0.0; //==LEGAL_COLLAPSE
127  typename Mesh::FaceHandle fhC, fhB;
128  Vec3f B,C;
129 
130  if ( min_r_ < 0.0f ) // continues mode
131  {
132  C = vector_cast<Vec3f>(Base::mesh().point( Base::mesh().to_vertex_handle(*voh_it)));
133  fhC = Base::mesh().face_handle( *voh_it );
134 
135  for (++voh_it; voh_it.is_valid(); ++voh_it)
136  {
137  B = C;
138  fhB = fhC;
139  C = vector_cast<Vec3f>(Base::mesh().point(Base::mesh().to_vertex_handle(*voh_it)));
140  fhC = Base::mesh().face_handle( *voh_it );
141 
142  if ( fhB == _ci.fl || fhB == _ci.fr )
143  continue;
144 
145  // simulate collapse using position of v1
146  r = roundness( vector_cast<Vec3f>(_ci.p1), B, C );
147 
148  // return the maximum non-roundness
149  priority = std::max( priority, (1.0-r) );
150 
151  }
152  }
153  else // binary mode
154  {
155  C = vector_cast<Vec3f>(Base::mesh().point( Base::mesh().to_vertex_handle(*voh_it)));
156  fhC = Base::mesh().face_handle( *voh_it );
157 
158  for (++voh_it; voh_it.is_valid() && (priority==Base::LEGAL_COLLAPSE); ++voh_it)
159  {
160  B = C;
161  fhB = fhC;
162  C = vector_cast<Vec3f>(Base::mesh().point(Base::mesh().to_vertex_handle(*voh_it)));
163  fhC = Base::mesh().face_handle( *voh_it );
164 
165  if ( fhB == _ci.fl || fhB == _ci.fr )
166  continue;
167 
168  priority = ( (r=roundness( vector_cast<Vec3f>(_ci.p1), B, C )) < min_r_)
169  ? Base::ILLEGAL_COLLAPSE : Base::LEGAL_COLLAPSE;
170  }
171  }
172 
173  return (float) priority;
174  }
175 
177  void set_error_tolerance_factor(double _factor) {
178  if (this->is_binary()) {
179  if (_factor >= 0.0 && _factor <= 1.0) {
180  // the smaller the factor, the smaller min_r_ gets
181  // thus creating a stricter constraint
182  // division by error_tolerance_factor_ is for normalization
183  value_type min_roundness = min_r_ * static_cast<value_type>(_factor / this->error_tolerance_factor_);
184  set_min_roundness(min_roundness);
185  this->error_tolerance_factor_ = _factor;
186  }
187 }
188  }
189 
190 
191 public: // specific methods
192 
193  void set_min_angle( float _angle, bool /* _binary=true */ )
194  {
195  assert( _angle > 0 && _angle < 60 );
196 
197  _angle = float(M_PI * _angle /180.0);
198 
199  Vec3f A,B,C;
200 
201  A = Vec3f( 0.0f, 0.0f, 0.0f);
202  B = Vec3f( 2.0f * cos(_angle), 0.0f, 0.0f);
203  C = Vec3f( cos(_angle), sin(_angle), 0.0f);
204 
205  double r1 = roundness(A,B,C);
206 
207  _angle = float(0.5 * ( M_PI - _angle ));
208 
209  A = Vec3f( 0.0f, 0.0f, 0.0f);
210  B = Vec3f( 2.0f*cos(_angle), 0.0f, 0.0f);
211  C = Vec3f( cos(_angle), sin(_angle), 0.0f);
212 
213  double r2 = roundness(A,B,C);
214 
215  set_min_roundness( value_type(std::min(r1,r2)), true );
216  }
217 
225  void set_min_roundness( value_type _min_roundness, bool _binary=true )
226  {
227  assert( 0.0 <= _min_roundness && _min_roundness <= 1.0 );
228  min_r_ = _min_roundness;
229  Base::set_binary(_binary);
230  }
231 
234  {
235  min_r_ = -1.0;
236  Base::set_binary(false);
237  }
238 
239  // Compute a normalized roundness of a triangle ABC
240  //
241  // Having
242  // A,B,C corner points of triangle
243  // a,b,c the vectors BC,CA,AB
244  // Area area of triangle
245  //
246  // then define
247  //
248  // radius of circumference
249  // R := -----------------------
250  // length of shortest edge
251  //
252  // ||a|| * ||b|| * ||c||
253  // ---------------------
254  // 4 * Area ||a|| * ||b|| * ||c||
255  // = ----------------------- = -----------------------------------
256  // min( ||a||,||b||,||c||) 4 * Area * min( ||a||,||b||,||c|| )
257  //
258  // ||a|| * ||b|| * ||c||
259  // = -------------------------------------------------------
260  // 4 * 1/2 * ||cross(B-A,C-A)|| * min( ||a||,||b||,||c|| )
261  //
262  // a'a * b'b * c'c
263  // R� = ----------------------------------------------------------
264  // 4 * cross(B-A,C-A)'cross(B-A,C-A) * min( a'a, b'b, c'c )
265  //
266  // a'a * b'b * c'c
267  // R = 1/2 * sqrt(---------------------------)
268  // AA * min( a'a, b'b, c'c )
269  //
270  // At angle 60� R has it's minimum for all edge lengths = sqrt(1/3)
271  //
272  // Define normalized roundness
273  //
274  // nR := sqrt(1/3) / R
275  //
276  // AA * min( a'a, b'b, c'c )
277  // = sqrt(4/3) * sqrt(---------------------------)
278  // a'a * b'b * c'c
279  //
280  double roundness( const Vec3f& A, const Vec3f& B, const Vec3f &C )
281  {
282  const value_type epsilon = value_type(1e-15);
283 
284  static const value_type sqrt43 = value_type(sqrt(4.0/3.0)); // 60�,a=b=c, **)
285 
286  Vec3f vecAC = C-A;
287  Vec3f vecAB = B-A;
288 
289  // compute squared values to avoid sqrt-computations
290  value_type aa = (B-C).sqrnorm();
291  value_type bb = vecAC.sqrnorm();
292  value_type cc = vecAB.sqrnorm();
293  value_type AA = cross(vecAC,vecAB).sqrnorm(); // without factor 1/4 **)
294 
295  if ( AA < epsilon )
296  return 0.0;
297 
298  double nom = AA * std::min( std::min(aa,bb),cc );
299  double denom = aa * bb * cc;
300  double nR = sqrt43 * sqrt(nom/denom);
301 
302  return nR;
303  }
304 
305  private:
306 
307  value_type min_r_;
308 };
309 
310 
311 //=============================================================================
312 } // END_NS_DECIMATER
313 } // END_NS_OPENMESH
314 //=============================================================================
315 #if defined(OM_CC_MSVC) && defined(OM_ENABLE_WARNINGS)
316 # pragma warning(default : OM_ENABLE_WARNINGS)
317 # undef OM_ENABLE_WARNINGS
318 #endif
319 //=============================================================================
320 #endif // OPENMESH_DECIMATER_MODROUNDNESST_HH defined
321 //=============================================================================
322 
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
osg::Vec3f cross(const osg::Vec3f &_v1, const osg::Vec3f &_v2)
Adapter for osg vector member computing a scalar product.
decltype(std::declval< S >() *std::declval< S >()) sqrnorm() const
compute squared euclidean norm
Definition: Vector11T.hh:397
Mesh::FaceHandle fl
Left face.
VectorT< float, 3 > Vec3f
Definition: Vector11T.hh:811
void unset_min_roundness()
Unset minimum value constraint and enable non-binary mode.
Mesh::FaceHandle fr
Right face.
Use Roundness of triangles to control decimation.
Mesh::VertexHandle v0
Vertex to be removed.
void set_min_roundness(value_type _min_roundness, bool _binary=true)
float collapse_priority(const CollapseInfo &_ci)
Mesh::Point p1
Positions of remaining vertex.
Kernel::ConstVertexOHalfedgeIter ConstVertexOHalfedgeIter
Circulator.
Definition: PolyMeshT.hh:173
void set_error_tolerance_factor(double _factor)
set the percentage of minimum roundness
ModRoundnessT(MeshT &_dec)
Constructor.
bool is_binary(void) const
Returns true if criteria returns a binary value.
Definition: ModBaseT.hh:220