diff --git a/include/Algo/ImplicitHierarchicalMesh/ihm.h b/include/Algo/ImplicitHierarchicalMesh/ihm.h
index 7d7974bdcdd834f319778a5f98d5d09ae8ad30dc..a00e077e6f792b85177190103df5305590c9ad65 100644
--- a/include/Algo/ImplicitHierarchicalMesh/ihm.h
+++ b/include/Algo/ImplicitHierarchicalMesh/ihm.h
@@ -193,6 +193,12 @@ public:
 	 */
 	Dart faceOldestDart(Dart d) ;
 
+	//! Test if dart d and e belong to the same face
+	/*! @param d a dart
+	 *  @param e a dart
+	 */
+	bool sameFace(Dart d, Dart e) ;
+
 	/**
 	 * Return true if the edge of d in the current level map
 	 * has already been subdivided to the next level
diff --git a/include/Algo/MovingObjects/particle_cell_2D.hpp b/include/Algo/MovingObjects/particle_cell_2D.hpp
index 0563077098077ba3738eb2802a33f9ef8e32dd35..62b45b42b8edef75186a57c4fa9daaf365c850ed 100644
--- a/include/Algo/MovingObjects/particle_cell_2D.hpp
+++ b/include/Algo/MovingObjects/particle_cell_2D.hpp
@@ -21,6 +21,7 @@
 * Contact information: cgogn@unistra.fr                                        *
 *                                                                              *
 *******************************************************************************/
+//#define DEBUG
 namespace CGoGN
 {
 
@@ -137,7 +138,8 @@ void ParticleCell2D<PFP>::vertexState(const VEC3& goal)
 					{
 						if(Geometry::isPointOnHalfEdge<PFP>(m,d,positionAttribut,goal)
 								&& Geometry::isPointOnHalfEdge<PFP>(m,this->m.phi2(d),positionAttribut,goal)
-								&& this->getOrientationEdge(goal, this->d) == Geom::ALIGNED)
+								)
+//								&& this->getOrientationEdge(goal, this->d) == Geom::ALIGNED) //TODO to check / alignment orientation test pb ?
 						{
 							edgeState(goal) ;
 							return;
@@ -145,7 +147,6 @@ void ParticleCell2D<PFP>::vertexState(const VEC3& goal)
 						this->d = this->m.phi2_1(this->d) ;
 					} while (this->getOrientationEdge(goal, this->m.phi2_1(this->d)) != Geom::RIGHT && dd_vert != this->d) ;
 
-
 					this->setState(VERTEX) ;
 					this->Algo::MovingObjects::ParticleBase < PFP > ::move(goal) ;
 					return ;
@@ -180,6 +181,17 @@ void ParticleCell2D<PFP>::edgeState(const VEC3& goal, Geom::Orientation2D sideOf
 {
 #ifdef DEBUG
 	CGoGNout << "edgeState" << d << CGoGNendl ;
+
+	VEC3 P(goal);
+	VEC3 Pa(positionAttribut[d]);
+	VEC3 Pb(positionAttribut[m.phi2(d)]);
+	float p = (P[0] - Pa[0]) * (Pb[1] - Pa[1]) - (Pb[0] - Pa[0]) * (P[1] - Pa[1]) ;
+	CGoGNout<<"p :"<<p<<CGoGNendl;
+
+
+	float p2 = (P[0] - Pb[0]) * (Pa[1] - Pb[1]) - (Pa[0] - Pb[0]) * (P[1] - Pb[1]) ;
+	CGoGNout<<"p2 :"<<p2<<CGoGNendl;
+
 #endif
 
 	assert(goal.isFinite()) ;
@@ -445,3 +457,4 @@ void ParticleCell2D<PFP>::faceState(const VEC3& goal)
 }
 } //namespaces
 }
+//#undef DEBUG
diff --git a/include/Algo/MovingObjects/particle_cell_2D_memo.hpp b/include/Algo/MovingObjects/particle_cell_2D_memo.hpp
index 28664d364577cc3d58843d6480b765344f496a0c..49c58a187c12c304ee5b526aec4358e0a640ec2a 100644
--- a/include/Algo/MovingObjects/particle_cell_2D_memo.hpp
+++ b/include/Algo/MovingObjects/particle_cell_2D_memo.hpp
@@ -42,6 +42,7 @@ std::vector<Dart> ParticleCell2DMemo<PFP>::move(const VEC3& goal)
 	{
 		CellMarkerMemo<FACE> memo_cross(this->m);
 
+
 		switch (this->getState())
 		{
 			case VERTEX :
@@ -139,8 +140,8 @@ void ParticleCell2DMemo<PFP>::vertexState(const VEC3& current, CellMarkerMemo<FA
 					do
 					{
 						if(Geometry::isPointOnHalfEdge<PFP>(this->m,this->d,this->positionAttribut,current)
-								&& Geometry::isPointOnHalfEdge<PFP>(this->m,this->m.phi2(this->d),this->positionAttribut,current)
-								&& this->getOrientationEdge(current, this->d) == Geom::ALIGNED)
+								&& Geometry::isPointOnHalfEdge<PFP>(this->m,this->m.phi2(this->d),this->positionAttribut,current))
+//								&& this->getOrientationEdge(current, this->d) == Geom::ALIGNED)
 						{
 
 							this->edgeState(current,memo_cross) ;
diff --git a/include/Geometry/inclusion.hpp b/include/Geometry/inclusion.hpp
index 33cc898243977469e54e34796079ec5f44a86bb3..9282437041e3b85599869dec5bf4dab977827c34 100644
--- a/include/Geometry/inclusion.hpp
+++ b/include/Geometry/inclusion.hpp
@@ -166,7 +166,7 @@ bool arePointsEquals(const VEC& point1, const VEC& point2)
 {
 	VEC v(point1 - point2);
 
-#define PRECISION 1e-10
+#define PRECISION 1e-5
 	return v.norm2() <= PRECISION ;
 #undef PRECISION
 }
diff --git a/include/Geometry/orientation.hpp b/include/Geometry/orientation.hpp
index 0ae073141c1bb6dcc4312073f1e15cbebace62b8..ea45d04c6662b2e18f3cd8229fa5527b42364265 100644
--- a/include/Geometry/orientation.hpp
+++ b/include/Geometry/orientation.hpp
@@ -35,7 +35,7 @@ Orientation2D testOrientation2D(const VEC3& P, const VEC3& Pa, const VEC3& Pb)
 {
 
 	typedef typename VEC3::DATA_TYPE T ;
-	const T zero = 0.00001 ;
+	const T zero = 0.000001 ;
 
 	T p = (P[0] - Pa[0]) * (Pb[1] - Pa[1]) - (Pb[0] - Pa[0]) * (P[1] - Pa[1]) ;
 
diff --git a/src/Algo/ImplicitHierarchicalMesh/ihm.cpp b/src/Algo/ImplicitHierarchicalMesh/ihm.cpp
index b67f157a624b580f8973a5cb09bcfd20c5658414..d8ac802d7495cfa5e9e3c3429083f00d0534f3f9 100644
--- a/src/Algo/ImplicitHierarchicalMesh/ihm.cpp
+++ b/src/Algo/ImplicitHierarchicalMesh/ihm.cpp
@@ -227,6 +227,18 @@ Dart ImplicitHierarchicalMap::faceOldestDart(Dart d)
 	return oldest ;
 }
 
+bool ImplicitHierarchicalMap::sameFace(Dart d, Dart e)
+{
+	Dart it = d ;
+	do
+	{
+		if(it == e)
+			return true ;
+		it = phi1(it) ;
+	} while(it != d) ;
+	return false ;
+}
+
 bool ImplicitHierarchicalMap::edgeIsSubdivided(Dart d)
 {
 	assert(m_dartLevel[d] <= m_curLevel || !"Access to a dart introduced after current level") ;