Begin of decim with colors grad+opt

include/Algo/Decimation/approximator.h

@@ -41,19 +41,20 @@ namespace Decimation
 
 enum ApproximatorType
 {
-	A_QEM,
-	A_MidEdge,
-	A_CornerCutting,
-	A_TangentPredict1,
-	A_TangentPredict2,
-	A_NormalArea,
-	A_ColorNaive,
-	A_ColorQEMext,
-	A_Lightfield,
+	A_QEM = 0,
+	A_MidEdge = 1,
+	A_CornerCutting = 2,
+	A_TangentPredict1 = 3,
+	A_TangentPredict2 = 4,
+	A_NormalArea = 5,
+	A_ColorNaive = 6,
+	A_ColorQEMext = 7,
+	A_GeomColorOpt = 8,
+	A_Lightfield = 9,
 	// note: the following "h" prefix means that half-edges are prioritized instead of edges.
-	A_hHalfCollapse,
-	A_hQEM,
-	A_hLightfieldHalf
+	A_hHalfCollapse = 10,
+	A_hQEM = 11,
+	A_hLightfieldHalf = 12
 } ;
 
 template <typename PFP>
@@ -164,13 +165,17 @@ public:
 	void saveApprox(Dart d)
 	{
 		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+		{
 			m_app[i] = m_approx[i][d] ;
+		}
 	}
 
 	void affectApprox(Dart d)
 	{
 		for (unsigned int i = 0 ; i < m_attrV.size() ; ++i)
+		{
 			m_attrV[i]->operator[](d) = m_app[i] ;
+		}
 	}
 
 	const T& getApprox(Dart d, unsigned int index = 0) const

include/Algo/Decimation/colorPerVertexApproximator.h

@@ -121,44 +121,43 @@ public:
 	void approximate(Dart d) ;
 } ;
 
-/*
+
 template <typename PFP>
-class Approximator_ColorQEMextHalfCollapse : public Approximator<PFP, typename PFP::VEC3>
+class Approximator_GeomColOpt : public Approximator<PFP, typename PFP::VEC3, EDGE>
 {
 public:
 	typedef typename PFP::MAP MAP ;
 	typedef typename PFP::REAL REAL ;
 	typedef typename PFP::VEC3 VEC3 ;
-	typedef Geom::Vector<6,REAL> VEC6 ;
 
 protected:
-	VertexAttribute<Utils::QuadricNd<REAL,6> > m_quadric ;
+	VertexAttribute<Utils::Quadric<REAL> > m_quadric ;
 	VertexAttribute<VEC3> *m_position ;
 	VertexAttribute<VEC3> *m_color ;
 
 public:
-	Approximator_ColorQEMextHalfCollapse(MAP& m, std::vector<VertexAttribute<VEC3>* >& attr, Predictor<PFP, VEC3>* pred = NULL) :
-		Approximator<PFP, VEC3>(m, attr, pred)
+	Approximator_GeomColOpt(MAP& m, std::vector<VertexAttribute<VEC3>* >& attr, Predictor<PFP, VEC3>* pred = NULL) :
+		Approximator<PFP, VEC3, EDGE>(m, attr, pred)
 	{
-		assert(attr.size() > 1 || !"Approximator_ColorQEMext_HalfCollapse: there are not sufficient attributes provided") ;
+		assert(attr.size() > 1 || !"Approximator_GeomColOpt: there are not sufficient attributes provided") ;
 
 		m_position = this->m_attrV[0] ;
 		m_color = this->m_attrV[1] ;
 	}
 
-	~Approximator_ColorQEMextHalfCollapse()
+	~Approximator_GeomColOpt()
 	{}
 
 	ApproximatorType getType() const
 	{
-		return A_ColorQEMextHalfCollapse ;
+		return A_GeomColorOpt ;
 	}
 
 	bool init() ;
 
 	void approximate(Dart d) ;
 } ;
-*/
+
 
 } //namespace Decimation
 

include/Algo/Decimation/colorPerVertexApproximator.hpp

@@ -165,6 +165,102 @@ void Approximator_ColorQEMext<PFP>::approximate(Dart d)
 	}
 }
 
+/************************************************************************************
+ *                    GEOM + COLOR OPTIMIZED ERROR METRIC                           *
+ ************************************************************************************/
+template <typename PFP>
+bool Approximator_GeomColOpt<PFP>::init()
+{
+	m_quadric = this->m_map.template getAttribute<Utils::Quadric<REAL>, VERTEX>("QEMquadric") ;
+	// Does not require to be valid (if it is not, altenatives will be used).
+
+	if(this->m_predictor)
+	{
+		return false ;
+	}
+
+	return m_position->isValid() && m_color->isValid() ;
+}
+
+template <typename PFP>
+void Approximator_GeomColOpt<PFP>::approximate(Dart d)
+{
+	MAP& m = this->m_map ;
+
+	// get some darts
+	Dart dd = m.phi2(d) ;
+
+	// POSITION
+	Utils::Quadric<REAL> q1, q2 ;
+	if(!m_quadric.isValid()) // if the selector is not QEM, compute local error quadrics
+	{
+		// compute the error quadric associated to v1
+		Dart it = d ;
+		do
+		{
+			Utils::Quadric<REAL> q(this->m_attrV[0]->operator[](it), this->m_attrV[0]->operator[](m.phi1(it)), this->m_attrV[0]->operator[](m.phi_1(it))) ;
+			q1 += q ;
+			it = m.phi2_1(it) ;
+		} while(it != d) ;
+
+		// compute the error quadric associated to v2
+		it = dd ;
+		do
+		{
+			Utils::Quadric<REAL> q(this->m_attrV[0]->operator[](it), this->m_attrV[0]->operator[](m.phi1(it)), this->m_attrV[0]->operator[](m.phi_1(it))) ;
+			q2 += q ;
+			it = m.phi2_1(it) ;
+		} while(it != dd) ;
+	}
+	else // if the selector is QEM, use the error quadrics computed by the selector
+	{
+		q1 = m_quadric[d] ;
+		q2 = m_quadric[dd] ;
+	}
+
+	Utils::Quadric<REAL> quad ;
+	quad += q1 ;	// compute the sum of the
+	quad += q2 ;	// two vertices quadrics
+
+	VEC3 res ;
+	bool opt = quad.findOptimizedPos(res) ;	// try to compute an optimized position for the contraction of this edge
+
+	const VEC3& p0 = this->m_attrV[0]->operator[](d) ;    // let the new vertex lie
+	const VEC3& p1 = this->m_attrV[0]->operator[](dd) ;   // on either one of the two endpoints
+
+	if(!opt)
+	{
+		VEC3 p12 = (p0 + p1) / 2.0f ;   // or the middle of the edge
+		REAL e1 = quad(p0) ;
+		REAL e2 = quad(p1) ;
+		REAL e12 = quad(p12) ;
+		REAL minerr = std::min(std::min(e1, e2), e12) ; // consider only the one for
+		if(minerr == e12)		this->m_approx[0][d] = p12 ;             // which the error is minimal
+		else if(minerr == e1)	this->m_approx[0][d] = p0 ;
+		else					this->m_approx[0][d] = p1 ;
+	}
+	// copy res into m_approx
+	else
+	{
+		this->m_approx[0][d] = res ;
+	}
+	const VEC3& p = this->m_approx[0][d] ;
+
+	// COLOR
+	const VEC3& c1 = this->m_attrV[1]->operator[](d) ;    // let the new vertex lie
+	const VEC3& c2 = this->m_attrV[1]->operator[](dd) ;   // on either one of the two endpoints
+
+	VEC3 e = p1 - p0 ;
+	VEC3 e1 = p - p0 ;
+	const REAL normE1 = e1.normalize() ;
+	const REAL normE = e.normalize() ;
+	REAL ratio = (e * e1)*normE1/normE ;
+	ratio = std::max(REAL(0),std::min(REAL(1),ratio)) ;
+
+	this->m_approx[1][d] = ratio*c1 + (1-ratio)*c2 ;
+}
+
+
 } //namespace Decimation
 
 }

include/Algo/Decimation/decimation.h

@@ -62,7 +62,7 @@ void decimate(
 	typename PFP::MAP& map,
 	SelectorType s,
 	ApproximatorType a,
-	std::vector<VertexAttribute<typename PFP::VEC3> *>& position,
+	std::vector<VertexAttribute<typename PFP::VEC3> *>& attribs,
 	unsigned int nbWantedVertices,
 	EdgeAttribute<typename PFP::REAL> *edgeErrors = NULL,
 	void (*callback_wrapper)(void*, const void*) = NULL, void *callback_object = NULL

include/Algo/Decimation/decimation.hpp

@@ -95,6 +95,13 @@ void decimate(
 			approximators.push_back(new Approximator_ColorQEMext<PFP>(map, attribs)) ;
 		}
 		break;
+		case A_GeomColorOpt :
+		{
+			// pos + col
+			assert(attribs.size() >= 2 || !"Decimate: A_GeomColorOpt --> not enough attribs provided") ;
+			approximators.push_back(new Approximator_GeomColOpt<PFP>(map, attribs)) ;
+		}
+		break ;
 		case A_hQEM :
 			// pos
 			approximators.push_back(new Approximator_QEMhalfEdge<PFP>(map, attribs)) ;
@@ -190,23 +197,29 @@ void decimate(
 		case S_hLightfield :
 			selector = new HalfEdgeSelector_Lightfield<PFP>(map, position, approximators) ;
 			break ;
-		case S_hLightfieldExp :
-			selector = new HalfEdgeSelector_LightfieldExp<PFP>(map, position, approximators) ;
+		case S_hLightfieldAvgColor :
+			selector = new HalfEdgeSelector_LightfieldAvgColor<PFP>(map, position, approximators) ;
 			break ;
 		case S_hLightfieldKCL :
 			selector = new HalfEdgeSelector_LightfieldKCL<PFP>(map, position, approximators) ;
 			break ;
 		case S_hColorExperimental:
-			selector = new HalfEdgeSelector_ColorExperimental<PFP>(map, position, approximators, selected) ;
+			selector = new HalfEdgeSelector_ColorExperimental<PFP>(map, position, approximators) ;
+			break ;
+		case S_hColorGradient:
+			selector = new HalfEdgeSelector_ColorGradient<PFP>(map, position, approximators) ;
 			break ;
 		case S_hLFexperimental:
-			selector = new HalfEdgeSelector_LFexperimental<PFP>(map, position, approximators, selected) ;
+			selector = new HalfEdgeSelector_LFexperimental<PFP>(map, position, approximators) ;
+			break ;
+		case S_hLFgradient:
+			selector = new HalfEdgeSelector_LFgradient<PFP>(map, position, approximators) ;
 			break ;
 		case S_hColorPerFace:
-			selector = new HalfEdgeSelector_ColorPerFace<PFP>(map, position, approximators, selected) ;
+			selector = new HalfEdgeSelector_ColorPerFace<PFP>(map, position, approximators) ;
 			break ;
 		case S_hLFperFace:
-			selector = new HalfEdgeSelector_LFperFace<PFP>(map, position, approximators, selected) ;
+			selector = new HalfEdgeSelector_LFperFace<PFP>(map, position, approximators) ;
 			break ;
 	}
 

include/Algo/Decimation/edgeSelector.h

@@ -701,7 +701,7 @@ private:
 
 	EdgeAttribute<EdgeInfo> edgeInfo ;
 
-	VertexAttribute<VEC3> m_pos, m_frameT, m_frameB, m_frameN ;
+	VertexAttribute<VEC3> m_pos, m_frameT, m_frameB, m_frameN, m_avgColor ;
 	std::vector<VertexAttribute<VEC3> > m_HF ;
 	int m_approxindex_pos, m_attrindex_pos ;
 	int m_approxindex_FN, m_attrindex_FN ;
@@ -733,6 +733,8 @@ public:
 		edgeInfo = m.template addAttribute<EdgeInfo, EDGE>("edgeInfo") ;
 		m_quadricGeom = m.template addAttribute<Utils::Quadric<REAL>, VERTEX>("QEMquadric") ;
 		m_quadricHF = m.template getAttribute<Utils::QuadricHF<REAL>, EDGE>("HFquadric") ;
+		m_avgColor = m.template getAttribute<typename PFP::VEC3, VERTEX>("color") ;
+		assert(m_avgColor.isValid()) ;
 	}
 	~EdgeSelector_Lightfield()
 	{

include/Algo/Decimation/edgeSelector.hpp

@@ -2533,10 +2533,15 @@ void EdgeSelector_Lightfield<PFP>::computeEdgeInfo(Dart d, EdgeInfo& einfo)
 	assert(m_quadricHF.isValid() | !"EdgeSelector_Lightfield<PFP>::computeEdgeInfo: quadricHF is not valid") ;
 	Utils::QuadricHF<REAL> quadHF = m_quadricHF[d] ;
 
+	assert(m_avgColor.isValid()) ;
+	VEC3 avgColDiff = m_avgColor[d] ;
+	avgColDiff -= m_avgColor[dd] ;
+
 	//std::cout << quadGeom(newPos) << " vs " << alpha/M_PI << " vs " << quadHF(newHF) << std::endl ;
 	// sum of QEM metric and frame orientation difference
 	const REAL& errG = quadGeom(newPos) ; // geom
-	const REAL& errAngle = alpha / M_PI ; // frame
+	//const REAL& errAngle = alpha / M_PI ; // frame
+	const REAL& errAngle = (alpha / M_PI) * avgColDiff.norm2() / 3. ; // avg color times covering area
 	const REAL& errLF = quadHF(newHF) ; // function coefficients
 
 	// Check if errated values appear
@@ -2544,7 +2549,8 @@ void EdgeSelector_Lightfield<PFP>::computeEdgeInfo(Dart d, EdgeInfo& einfo)
 		einfo.valid = false ;
 	else
 	{
-		einfo.it = edges.insert(std::make_pair(std::max(errG + errAngle + errLF, REAL(0)), d)) ;
+		einfo.it = edges.insert(std::make_pair(std::max(errG, REAL(0)) + 10*(errAngle + errLF), d)) ;
+		//einfo.it = edges.insert(std::make_pair(errG+errLF+errAngle, d)) ;
 		einfo.valid = true ;
 	}
 }

include/Algo/Decimation/halfEdgeSelector.h

@@ -166,16 +166,18 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
-			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
 			{
 				(*errors)[d] = halfEdgeInfo[dd].it->first ;
 			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
 		}
 	}
 } ;
@@ -259,16 +261,18 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
-			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
 			{
 				(*errors)[d] = halfEdgeInfo[dd].it->first ;
 			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
 		}
 	}
 } ;
@@ -277,7 +281,7 @@ public:
  *                                 HALF-EDGE LIGHTFIELD METRIC experimental                                      *
  *****************************************************************************************************************/
 template <typename PFP>
-class HalfEdgeSelector_LightfieldExp : public EdgeSelector<PFP>
+class HalfEdgeSelector_LightfieldAvgColor : public EdgeSelector<PFP>
 {
 public:
 	typedef typename PFP::MAP MAP ;
@@ -317,7 +321,7 @@ private:
 	void recomputeQuadric(const Dart d, const bool recomputeNeighbors = false) ;
 
 public:
-	HalfEdgeSelector_LightfieldExp(MAP& m, VertexAttribute<typename PFP::VEC3>& pos, std::vector<ApproximatorGen<PFP>*>& approx) :
+	HalfEdgeSelector_LightfieldAvgColor(MAP& m, VertexAttribute<typename PFP::VEC3>& pos, std::vector<ApproximatorGen<PFP>*>& approx) :
 		EdgeSelector<PFP>(m, pos, approx),
 		m_approxindex_pos(-1),
 		m_attrindex_pos(-1),
@@ -331,12 +335,12 @@ public:
 		m_avgColor = m.template getAttribute<typename PFP::VEC3, VERTEX>("color") ;
 		assert(m_avgColor.isValid()) ;
 	}
-	~HalfEdgeSelector_LightfieldExp()
+	~HalfEdgeSelector_LightfieldAvgColor()
 	{
 		this->m_map.removeAttribute(m_quadricGeom) ;
 		this->m_map.removeAttribute(halfEdgeInfo) ;
 	}
-	SelectorType getType() { return S_hLightfieldExp ; }
+	SelectorType getType() { return S_hLightfieldAvgColor ; }
 	bool init() ;
 	bool nextEdge(Dart& d) ;
 	void updateBeforeCollapse(Dart d) ;
@@ -354,16 +358,18 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
-			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
 			{
 				(*errors)[d] = halfEdgeInfo[dd].it->first ;
 			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
 		}
 	}
 } ;
@@ -460,17 +466,18 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
-			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
 			{
-				(*errors)[dd] = halfEdgeInfo[dd].it->first ;
+				(*errors)[d] = halfEdgeInfo[dd].it->first ;
 			}
-			//m_avgColor[d] = VEC3(m_visualImportance[d]/6.,m_visualImportance[d]/6.,m_visualImportance[d]/6.) ;
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
 		}
 	}
 } ;
@@ -513,7 +520,7 @@ private:
 	//void recomputeQuadric(const Dart d, const bool recomputeNeighbors = false) ;
 	void recomputeQuadric(const Dart d) ;
 
-	typename PFP::REAL computeExperimentalColorError(const Dart& v0, const Dart& v1) ;
+	typename PFP::VEC3 computeExperimentalColorError(const Dart& v0, const Dart& v1) ;
 
 
 public:
@@ -550,20 +557,114 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
+			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
+			{
+				(*errors)[d] = halfEdgeInfo[dd].it->first ;
+			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
+		}
+	}
+} ;
+
+/*****************************************************************************************************************
+ *                                 HALF-EDGE COLOR GRADIENT ERR                                                  *
+ *****************************************************************************************************************/
+template <typename PFP>
+class HalfEdgeSelector_ColorGradient : public EdgeSelector<PFP>
+{
+public:
+	typedef typename PFP::MAP MAP ;
+	typedef typename PFP::REAL REAL ;
+	typedef typename PFP::VEC3 VEC3 ;
+
+private:
+	typedef	struct
+	{
+		typename std::multimap<float,Dart>::iterator it ;
+		bool valid ;
+		static std::string CGoGNnameOfType() { return "ColorExperimentalHalfEdgeInfo" ; }
+	} QEMextColorHalfEdgeInfo ;
+	typedef NoMathIOAttribute<QEMextColorHalfEdgeInfo> HalfEdgeInfo ;
+
+	DartAttribute<HalfEdgeInfo> halfEdgeInfo ;
+	VertexAttribute<Utils::Quadric<REAL> > m_quadric ;
+
+	VertexAttribute<VEC3> m_pos, m_color ;
+	int m_approxindex_pos, m_attrindex_pos ;
+	int m_approxindex_color, m_attrindex_color ;
+
+	std::vector<Approximator<PFP, typename PFP::VEC3,DART>* > m_approx ;
+
+	std::multimap<float,Dart> halfEdges ;
+	typename std::multimap<float,Dart>::iterator cur ;
+
+	void initHalfEdgeInfo(Dart d) ;
+	void updateHalfEdgeInfo(Dart d) ;
+	void computeHalfEdgeInfo(Dart d, HalfEdgeInfo& einfo) ;
+	//void recomputeQuadric(const Dart d, const bool recomputeNeighbors = false) ;
+	void recomputeQuadric(const Dart d) ;
+
+	typename PFP::VEC3 computeGradientColorError(const Dart& v0, const Dart& v1) ;
+
+
+public:
+	HalfEdgeSelector_ColorGradient(MAP& m, VertexAttribute<typename PFP::VEC3>& pos, std::vector<ApproximatorGen<PFP>*>& approx) :
+		EdgeSelector<PFP>(m, pos, approx),
+		m_approxindex_pos(-1),
+		m_attrindex_pos(-1),
+		m_approxindex_color(-1),
+		m_attrindex_color(-1)
+	{
+		halfEdgeInfo = m.template addAttribute<HalfEdgeInfo, DART>("halfEdgeInfo") ;
+		m_quadric = m.template addAttribute<Utils::Quadric<REAL>, VERTEX>("QEMquadric") ;
+	}
+	~HalfEdgeSelector_ColorGradient()
+	{
+		this->m_map.removeAttribute(m_quadric) ;
+		this->m_map.removeAttribute(halfEdgeInfo) ;
+	}
+	SelectorType getType() { return S_hColorGradient ; }
+	bool init() ;
+	bool nextEdge(Dart& d) ;
+	void updateBeforeCollapse(Dart d) ;
+	void updateAfterCollapse(Dart d2, Dart dd2) ;
+
+	void updateWithoutCollapse() { }
+
+	void getEdgeErrors(EdgeAttribute<typename PFP::REAL> *errors)
+	{
+		assert(errors != NULL || !"EdgeSelector::setColorMap requires non null vertexattribute argument") ;
+		if (!errors->isValid())
+			std::cerr << "EdgeSelector::setColorMap requires valid edgeattribute argument" << std::endl ;
+		assert(halfEdgeInfo.isValid()) ;
+
+		TraversorE<typename PFP::MAP> travE(this->m_map) ;
+		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
+		{
 			Dart dd = this->m_map.phi2(d) ;
+			if (halfEdgeInfo[d].valid)
+			{
+				(*errors)[d] = halfEdgeInfo[d].it->first ;
+			}
 			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
 			{
 				(*errors)[d] = halfEdgeInfo[dd].it->first ;
 			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
 		}
 	}
 } ;
 
+
 /*****************************************************************************************************************
  *                                 HALF-EDGE LF EXPERIMENTAL METRIC                                              *
  *****************************************************************************************************************/
@@ -653,20 +754,128 @@ public:
 		TraversorE<typename PFP::MAP> travE(this->m_map) ;
 		for(Dart d = travE.begin() ; d != travE.end() ; d = travE.next())
 		{
-			(*errors)[d] = -1 ;
+			Dart dd = this->m_map.phi2(d) ;
 			if (halfEdgeInfo[d].valid)
 			{
 				(*errors)[d] = halfEdgeInfo[d].it->first ;
 			}
+			if (halfEdgeInfo[dd].valid && halfEdgeInfo[dd].it->first < (*errors)[d])
+			{
+				(*errors)[d] = halfEdgeInfo[dd].it->first ;
+			}
+			if (!(halfEdgeInfo[d].valid || halfEdgeInfo[dd].valid))
+				(*errors)[d] = -1 ;
+
+		}
+	}
+} ;
+
+/*****************************************************************************************************************
+ *                                 HALF-EDGE LF EXPERIMENTAL METRIC                                              *
+ *****************************************************************************************************************/
+template <typename PFP>
+class HalfEdgeSelector_LFgradient : public EdgeSelector<PFP>
+{
+public:
+	typedef typename PFP::MAP MAP ;