OpenMesh
ModAspectRatioT_impl.hh
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41 
42 
46 //=============================================================================
47 //
48 // CLASS ModAspectRatioT - IMPLEMENTATION
49 //
50 //=============================================================================
51 #define OPENMESH_DECIMATER_MODASPECTRATIOT_C
52 
53 //== INCLUDES =================================================================
54 
55 #include "ModAspectRatioT.hh"
56 
57 //== NAMESPACES ===============================================================
58 
59 namespace OpenMesh {
60 namespace Decimater {
61 
62 //== IMPLEMENTATION ==========================================================
63 
64 template<class MeshT>
65 typename ModAspectRatioT<MeshT>::Scalar ModAspectRatioT<MeshT>::aspectRatio(
66  const Point& _v0, const Point& _v1, const Point& _v2) {
67  Point d0 = _v0 - _v1;
68  Point d1 = _v1 - _v2;
69 
70  // finds the max squared edge length
71  Scalar l2, maxl2 = d0.sqrnorm();
72  if ((l2 = d1.sqrnorm()) > maxl2)
73  maxl2 = l2;
74  // keep searching for the max squared edge length
75  d1 = _v2 - _v0;
76  if ((l2 = d1.sqrnorm()) > maxl2)
77  maxl2 = l2;
78 
79  // squared area of the parallelogram spanned by d0 and d1
80  Scalar a2 = (d0 % d1).sqrnorm();
81 
82  // the area of the triangle would be
83  // sqrt(a2)/2 or length * height / 2
84  // aspect ratio = length / height
85  // = length * length / (2*area)
86  // = length * length / sqrt(a2)
87 
88  // returns the length of the longest edge
89  // divided by its corresponding height
90  return sqrt((maxl2 * maxl2) / a2);
91 }
92 
93 //-----------------------------------------------------------------------------
94 
95 template<class MeshT>
97  typename Mesh::FaceIter f_it, f_end(mesh_.faces_end());
98  typename Mesh::FVIter fv_it;
99 
100  for (f_it = mesh_.faces_begin(); f_it != f_end; ++f_it) {
101  fv_it = mesh_.fv_iter(*f_it);
102  typename Mesh::Point& p0 = mesh_.point(*fv_it);
103  typename Mesh::Point& p1 = mesh_.point(*(++fv_it));
104  typename Mesh::Point& p2 = mesh_.point(*(++fv_it));
105 
106  mesh_.property(aspect_, *f_it) = static_cast<typename Mesh::Scalar>(1.0) / aspectRatio(p0, p1, p2);
107  }
108 }
109 
110 //-----------------------------------------------------------------------------
111 
112 template<class MeshT>
113 void ModAspectRatioT<MeshT>::preprocess_collapse(const CollapseInfo& _ci) {
114  typename Mesh::FaceHandle fh;
115  typename Mesh::FVIter fv_it;
116 
117  for (typename Mesh::VFIter vf_it = mesh_.vf_iter(_ci.v0); vf_it.is_valid(); ++vf_it) {
118  fh = *vf_it;
119  if (fh != _ci.fl && fh != _ci.fr) {
120  fv_it = mesh_.fv_iter(fh);
121  typename Mesh::Point& p0 = mesh_.point(*fv_it);
122  typename Mesh::Point& p1 = mesh_.point(*(++fv_it));
123  typename Mesh::Point& p2 = mesh_.point(*(++fv_it));
124 
125  mesh_.property(aspect_, fh) = static_cast<typename Mesh::Scalar>(1.0) / aspectRatio(p0, p1, p2);
126  }
127  }
128 }
129 
130 //-----------------------------------------------------------------------------
131 
132 template<class MeshT>
133 float ModAspectRatioT<MeshT>::collapse_priority(const CollapseInfo& _ci) {
134  typename Mesh::VertexHandle v2, v3;
135  typename Mesh::FaceHandle fh;
136  const typename Mesh::Point *p1(&_ci.p1), *p2, *p3;
137  typename Mesh::Scalar r0, r1, r0_min(1.0), r1_min(1.0);
138  typename Mesh::ConstVertexOHalfedgeIter voh_it(mesh_, _ci.v0);
139 
140  v3 = mesh_.to_vertex_handle(*voh_it);
141  p3 = &mesh_.point(v3);
142 
143  while (voh_it.is_valid()) {
144  v2 = v3;
145  p2 = p3;
146 
147  ++voh_it;
148  v3 = mesh_.to_vertex_handle(*voh_it);
149  p3 = &mesh_.point(v3);
150 
151  fh = mesh_.face_handle(*voh_it);
152 
153  // if not boundary
154  if (fh.is_valid()) {
155  // aspect before
156  if ((r0 = mesh_.property(aspect_, fh)) < r0_min)
157  r0_min = r0;
158 
159  // aspect after
160  if (!(v2 == _ci.v1 || v3 == _ci.v1))
161  if ((r1 = static_cast<typename Mesh::Scalar>(1.0) / aspectRatio(*p1, *p2, *p3)) < r1_min)
162  r1_min = r1;
163  }
164  }
165 
166  if (Base::is_binary()) {
167  return
168  ((r1_min > r0_min) || (r1_min > min_aspect_)) ? float(Base::LEGAL_COLLAPSE) :
169  float(Base::ILLEGAL_COLLAPSE);
170 
171  } else {
172  if (r1_min > r0_min)
173  return 1.f - float(r1_min);
174  else
175  return
176  (r1_min > min_aspect_) ? 2.f - float(r1_min) : float(Base::ILLEGAL_COLLAPSE);
177  }
178 }
179 
180 //-----------------------------------------------------------------------------
181 
182 template<class MeshT>
184  if (_factor >= 0.0 && _factor <= 1.0) {
185  // the smaller the factor, the larger min_aspect_ gets
186  // thus creating a stricter constraint
187  // division by (2.0 - error_tolerance_factor_) is for normalization
188  float min_aspect = min_aspect_ * (2.f - float(_factor)) / (2.f - float(this->error_tolerance_factor_));
189  set_aspect_ratio(1.f/min_aspect);
190  this->error_tolerance_factor_ = _factor;
191  }
192 }
193 
194 //=============================================================================
195 }
196 }
197 //=============================================================================
void initialize()
precompute face aspect ratio
Definition: ModAspectRatioT_impl.hh:96
Kernel::Scalar Scalar
Scalar type.
Definition: PolyMeshT.hh:110
void preprocess_collapse(const CollapseInfo &_ci)
update aspect ratio of one-ring
Definition: ModAspectRatioT_impl.hh:113
float collapse_priority(const CollapseInfo &_ci)
Returns the collapse priority.
Definition: ModAspectRatioT_impl.hh:133
Kernel::VertexHandle VertexHandle
Handle for referencing the corresponding item.
Definition: PolyMeshT.hh:136
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition: MeshItems.hh:59
void set_error_tolerance_factor(double _factor)
set percentage of aspect ratio
Definition: ModAspectRatioT_impl.hh:183
Kernel::ConstVertexOHalfedgeIter ConstVertexOHalfedgeIter
Circulator.
Definition: PolyMeshT.hh:173

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