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Sqrt3T.hh
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//=============================================================================
//
// CLASS Sqrt3T
//
//=============================================================================
#ifndef OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
#define OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
//== INCLUDES =================================================================
#include <OpenMesh/Core/Mesh/Handles.hh>
#include <OpenMesh/Core/System/config.hh>
#include <OpenMesh/Tools/Subdivider/Uniform/SubdividerT.hh>
#if defined(_DEBUG) || defined(DEBUG)
// Makes life lot easier, when playing/messing around with low-level topology
// changing methods of OpenMesh
# include <OpenMesh/Tools/Utils/MeshCheckerT.hh>
# define ASSERT_CONSISTENCY( T, m ) \
assert(OpenMesh::Utils::MeshCheckerT<T>(m).check())
#else
# define ASSERT_CONSISTENCY( T, m )
#endif
// -------------------- STL
#include <vector>
#if defined(OM_CC_MIPS)
# include <math.h>
#else
# include <cmath>
#endif
//== NAMESPACE ================================================================
namespace OpenMesh { // BEGIN_NS_OPENMESH
namespace Subdivider { // BEGIN_NS_DECIMATER
namespace Uniform { // BEGIN_NS_DECIMATER
//== CLASS DEFINITION =========================================================
template <typename MeshType, typename RealType = double>
class Sqrt3T : public SubdividerT< MeshType, RealType >
{
public:
typedef RealType real_t;
typedef MeshType mesh_t;
typedef SubdividerT< mesh_t, real_t > parent_t;
typedef std::pair< real_t, real_t > weight_t;
typedef std::vector< std::pair<real_t,real_t> > weights_t;
public:
Sqrt3T(void) : parent_t(), _1over3( real_t(1.0/3.0) ), _1over27( real_t(1.0/27.0) )
{ init_weights(); }
explicit Sqrt3T(MeshType &_m) : parent_t(_m), _1over3( real_t(1.0/3.0) ), _1over27( real_t(1.0/27.0) )
{ init_weights(); }
virtual ~Sqrt3T() {}
public:
const char *name() const override { return "Uniform Sqrt3"; }
void init_weights(size_t _max_valence=50)
{
weights_.resize(_max_valence);
std::generate(weights_.begin(), weights_.end(), compute_weight());
}
protected:
bool prepare( MeshType& _m ) override
{
_m.request_edge_status();
_m.add_property( vp_pos_ );
_m.add_property( ep_nv_ );
_m.add_property( mp_gen_ );
_m.property( mp_gen_ ) = 0;
return _m.has_edge_status() && vp_pos_.is_valid()
&& ep_nv_.is_valid() && mp_gen_.is_valid();
}
bool cleanup( MeshType& _m ) override
{
_m.release_edge_status();
_m.remove_property( vp_pos_ );
_m.remove_property( ep_nv_ );
_m.remove_property( mp_gen_ );
return true;
}
bool subdivide( MeshType& _m, size_t _n , const bool _update_points = true) override
{
typename MeshType::Point pos(0,0,0), zero(0,0,0);
size_t &gen = _m.property( mp_gen_ );
for (size_t l=0; l<_n; ++l)
{
// tag existing edges
for (auto eh : _m.edges())
{
_m.status( eh ).set_tagged( true );
if ( (gen%2) && _m.is_boundary(eh) )
compute_new_boundary_points( _m, eh ); // *) creates new vertices
}
// do relaxation of old vertices, but store new pos in property vp_pos_
for (auto vh : _m.vertices())
{
if ( _m.is_boundary(vh) )
{
if ( gen%2 )
{
auto heh = _m.halfedge_handle(vh);
if (heh.is_valid()) // skip isolated newly inserted vertices *)
{
auto prev_heh = _m.prev_halfedge_handle(heh);
assert( _m.is_boundary(heh ) );
assert( _m.is_boundary(prev_heh) );
pos = _m.point(_m.to_vertex_handle(heh));
pos += _m.point(_m.from_vertex_handle(prev_heh));
pos *= real_t(4.0);
pos += real_t(19.0) * _m.point( vh );
pos *= _1over27;
_m.property( vp_pos_, vh ) = pos;
}
}
else
_m.property( vp_pos_, vh ) = _m.point( vh );
}
else
{
size_t valence=0;
pos = zero;
for ( auto vvh : _m.vv_range(vh))
{
pos += _m.point( vvh );
++valence;
}
pos *= weights_[ valence ].second;
pos += weights_[ valence ].first * _m.point(vh);
_m.property( vp_pos_, vh ) = pos;
}
}
// insert new vertices, but store pos in vp_pos_
for (auto fh : _m.faces())
{
if ( (gen%2) && _m.is_boundary(fh))
{
boundary_split( _m, fh );
}
else
{
auto fvit = _m.fv_iter( fh );
pos = _m.point( *fvit);
pos += _m.point(*(++fvit));
pos += _m.point(*(++fvit));
pos *= _1over3;
auto vh = _m.add_vertex( zero );
_m.property( vp_pos_, vh ) = pos;
_m.split( fh, vh );
}
}
// commit new positions (now iterating over all vertices)
for (auto vh : _m.vertices())
_m.set_point(vh, _m.property( vp_pos_, vh ) );
// flip old edges
for (auto eh : _m.edges())
if ( _m.status( eh ).tagged() && !_m.is_boundary( eh ) )
_m.flip(eh);
// Now we have an consistent mesh!
ASSERT_CONSISTENCY( MeshType, _m );
// increase generation by one
++gen;
}
return true;
}
private:
struct compute_weight
{
compute_weight() : valence(-1) { }
weight_t operator() (void)
{
#if !defined(OM_CC_MIPS)
using std::cos;
#endif
if (++valence)
{
real_t alpha = real_t( (4.0-2.0*cos(2.0*M_PI / real_t(valence)) )/9.0 );
return weight_t( real_t(1)-alpha, alpha/real_t(valence) );
}
return weight_t(real_t(0.0), real_t(0.0) );
}
int valence;
};
private:
// Pre-compute location of new boundary points for odd generations
// and store them in the edge property ep_nv_;
void compute_new_boundary_points( MeshType& _m,
const typename MeshType::EdgeHandle& _eh)
{
assert( _m.is_boundary(_eh) );
typename MeshType::HalfedgeHandle heh;
typename MeshType::VertexHandle vh1, vh2, vh3, vh4, vhl, vhr;
typename MeshType::Point zero(0,0,0), P1, P2, P3, P4;
/*
// *---------*---------*
// / \ / \ / \
// / \ / \ / \
// / \ / \ / \
// / \ / \ / \
// *---------*--#---#--*---------*
//
// ^ ^ ^ ^ ^ ^
// P1 P2 pl pr P3 P4
*/
// get halfedge pointing from P3 to P2 (outer boundary halfedge)
heh = _m.halfedge_handle(_eh,
_m.is_boundary(_m.halfedge_handle(_eh,1)));
assert( _m.is_boundary( _m.next_halfedge_handle( heh ) ) );
assert( _m.is_boundary( _m.prev_halfedge_handle( heh ) ) );
vh1 = _m.to_vertex_handle( _m.next_halfedge_handle( heh ) );
vh2 = _m.to_vertex_handle( heh );
vh3 = _m.from_vertex_handle( heh );
vh4 = _m.from_vertex_handle( _m.prev_halfedge_handle( heh ));
P1 = _m.point(vh1);
P2 = _m.point(vh2);
P3 = _m.point(vh3);
P4 = _m.point(vh4);
vhl = _m.add_vertex(zero);
vhr = _m.add_vertex(zero);
_m.property(vp_pos_, vhl ) = (P1 + real_t(16.0f) * P2 + real_t(10.0f) * P3) * _1over27;
_m.property(vp_pos_, vhr ) = ( real_t(10.0f) * P2 + real_t(16.0f) * P3 + P4) * _1over27;
_m.property(ep_nv_, _eh).first = vhl;
_m.property(ep_nv_, _eh).second = vhr;
}
void boundary_split( MeshType& _m, const typename MeshType::FaceHandle& _fh )
{
assert( _m.is_boundary(_fh) );
typename MeshType::VertexHandle vhl, vhr;
typename MeshType::FaceEdgeIter fe_it;
typename MeshType::HalfedgeHandle heh;
// find boundary edge
for( fe_it=_m.fe_iter( _fh ); fe_it.is_valid() && !_m.is_boundary( *fe_it ); ++fe_it ) {};
// use precomputed, already inserted but not linked vertices
vhl = _m.property(ep_nv_, *fe_it).first;
vhr = _m.property(ep_nv_, *fe_it).second;
/*
// *---------*---------*
// / \ / \ / \
// / \ / \ / \
// / \ / \ / \
// / \ / \ / \
// *---------*--#---#--*---------*
//
// ^ ^ ^ ^ ^ ^
// P1 P2 pl pr P3 P4
*/
// get halfedge pointing from P2 to P3 (inner boundary halfedge)
heh = _m.halfedge_handle(*fe_it,
_m.is_boundary(_m.halfedge_handle(*fe_it,0)));
typename MeshType::HalfedgeHandle pl_P3;
// split P2->P3 (heh) in P2->pl (heh) and pl->P3
boundary_split( _m, heh, vhl ); // split edge
pl_P3 = _m.next_halfedge_handle( heh ); // store next halfedge handle
boundary_split( _m, heh ); // split face
// split pl->P3 in pl->pr and pr->P3
boundary_split( _m, pl_P3, vhr );
boundary_split( _m, pl_P3 );
assert( _m.is_boundary( vhl ) && _m.halfedge_handle(vhl).is_valid() );
assert( _m.is_boundary( vhr ) && _m.halfedge_handle(vhr).is_valid() );
}
void boundary_split(MeshType& _m,
const typename MeshType::HalfedgeHandle& _heh,
const typename MeshType::VertexHandle& _vh)
{
assert( _m.is_boundary( _m.edge_handle(_heh) ) );
typename MeshType::HalfedgeHandle
heh(_heh),
opp_heh( _m.opposite_halfedge_handle(_heh) ),
new_heh, opp_new_heh;
typename MeshType::VertexHandle to_vh(_m.to_vertex_handle(heh));
typename MeshType::HalfedgeHandle t_heh;
/*
* P5
* *
* /|\
* / \
* / \
* / \
* / \
* /_ heh new \
* *-----\*-----\*\-----*
* ^ ^ t_heh
* _vh to_vh
*
* P1 P2 P3 P4
*/
// Re-Setting Handles
// find halfedge point from P4 to P3
for(t_heh = heh;
_m.next_halfedge_handle(t_heh) != opp_heh;
t_heh = _m.opposite_halfedge_handle(_m.next_halfedge_handle(t_heh)))
{}
assert( _m.is_boundary( t_heh ) );
new_heh = _m.new_edge( _vh, to_vh );
opp_new_heh = _m.opposite_halfedge_handle(new_heh);
// update halfedge connectivity
_m.set_next_halfedge_handle(t_heh, opp_new_heh); // P4-P3 -> P3-P2
// P2-P3 -> P3-P5
_m.set_next_halfedge_handle(new_heh, _m.next_halfedge_handle(heh));
_m.set_next_halfedge_handle(heh, new_heh); // P1-P2 -> P2-P3
_m.set_next_halfedge_handle(opp_new_heh, opp_heh); // P3-P2 -> P2-P1
// both opposite halfedges point to same face
_m.set_face_handle(opp_new_heh, _m.face_handle(opp_heh));
// let heh finally point to new inserted vertex
_m.set_vertex_handle(heh, _vh);
// let heh and new_heh point to same face
_m.set_face_handle(new_heh, _m.face_handle(heh));
// let opp_new_heh be the new outgoing halfedge for to_vh
// (replaces for opp_heh)
_m.set_halfedge_handle( to_vh, opp_new_heh );
// let opp_heh be the outgoing halfedge for _vh
_m.set_halfedge_handle( _vh, opp_heh );
}
void boundary_split( MeshType& _m,
const typename MeshType::HalfedgeHandle& _heh)
{
assert( _m.is_boundary( _m.opposite_halfedge_handle( _heh ) ) );
typename MeshType::HalfedgeHandle
heh(_heh),
n_heh(_m.next_halfedge_handle(heh));
typename MeshType::VertexHandle
to_vh(_m.to_vertex_handle(heh));
typename MeshType::HalfedgeHandle
heh2(_m.new_edge(to_vh,
_m.to_vertex_handle(_m.next_halfedge_handle(n_heh)))),
heh3(_m.opposite_halfedge_handle(heh2));
typename MeshType::FaceHandle
new_fh(_m.new_face()),
fh(_m.face_handle(heh));
// Relink (half)edges
#define set_next_heh set_next_halfedge_handle
#define next_heh next_halfedge_handle
_m.set_face_handle(heh, new_fh);
_m.set_face_handle(heh2, new_fh);
_m.set_next_heh(heh2, _m.next_heh(_m.next_heh(n_heh)));
_m.set_next_heh(heh, heh2);
_m.set_face_handle( _m.next_heh(heh2), new_fh);
// _m.set_face_handle( _m.next_heh(_m.next_heh(heh2)), new_fh);
_m.set_next_heh(heh3, n_heh);
_m.set_next_heh(_m.next_halfedge_handle(n_heh), heh3);
_m.set_face_handle(heh3, fh);
// _m.set_face_handle(n_heh, fh);
_m.set_halfedge_handle( fh, n_heh);
_m.set_halfedge_handle(new_fh, heh);
#undef set_next_halfedge_handle
#undef next_halfedge_handle
}
private:
weights_t weights_;
OpenMesh::VPropHandleT< typename MeshType::Point > vp_pos_;
OpenMesh::EPropHandleT< std::pair< typename MeshType::VertexHandle,
typename MeshType::VertexHandle> > ep_nv_;
OpenMesh::MPropHandleT< size_t > mp_gen_;
const real_t _1over3;
const real_t _1over27;
};
//=============================================================================
} // END_NS_UNIFORM
} // END_NS_SUBDIVIDER
} // END_NS_OPENMESH
//=============================================================================
#endif // OPENMESH_SUBDIVIDER_UNIFORM_SQRT3T_HH
//=============================================================================
SubdividerT.hh
OpenMesh
Contains all the mesh ingredients like the polygonal mesh, the triangle mesh, different mesh kernels ...
Definition MeshItems.hh:59
OpenMesh::BaseHandle::is_valid
bool is_valid() const
The handle is valid iff the index is not negative.
Definition Handles.hh:72
OpenMesh::VPropHandleT< typename MeshType::Point >
OpenMesh::EPropHandleT
Handle representing an edge property.
Definition Property.hh:447
OpenMesh::MPropHandleT< size_t >
OpenMesh::Subdivider::Uniform::Sqrt3T
Uniform Sqrt3 subdivision algorithm
Definition Sqrt3T.hh:99
OpenMesh::Subdivider::Uniform::Sqrt3T::cleanup
bool cleanup(MeshType &_m) override
Cleanup mesh after usage, e.g. remove added properties.
Definition Sqrt3T.hh:151
OpenMesh::Subdivider::Uniform::Sqrt3T::subdivide
bool subdivide(MeshType &_m, size_t _n, const bool _update_points=true) override
Subdivide mesh _m _n times.
Definition Sqrt3T.hh:160
OpenMesh::Subdivider::Uniform::Sqrt3T::prepare
bool prepare(MeshType &_m) override
Prepare mesh, e.g.
Definition Sqrt3T.hh:138
OpenMesh::Subdivider::Uniform::Sqrt3T::name
const char * name() const override
Return name of subdivision algorithm.
Definition Sqrt3T.hh:124
OpenMesh::Subdivider::Uniform::Sqrt3T::init_weights
void init_weights(size_t _max_valence=50)
Pre-compute weights.
Definition Sqrt3T.hh:128
OpenMesh::Subdivider::Uniform::SubdividerT
Abstract base class for uniform subdivision algorithms.
Definition SubdividerT.hh:89