diff --git a/src/fgt/filter_trioptimize/curvedgeflip.h b/src/fgt/filter_trioptimize/curvedgeflip.h
index fcc0b0d5e..f0a7c1837 100644
--- a/src/fgt/filter_trioptimize/curvedgeflip.h
+++ b/src/fgt/filter_trioptimize/curvedgeflip.h
@@ -77,41 +77,31 @@ protected:
 	{
 		CurvData res;
 		
-		float ang0 = math::Abs(Angle(v1->P() - v0->P(), v2->P() - v0->P() ));
-		float ang1 = math::Abs(Angle(v0->P() - v1->P(), v2->P() - v1->P() ));
-		float ang2 = M_PI - (ang0 + ang1);
+		float ang0 = math::Abs(Angle(v1->P() - v0->P(), v2->P() - v0->P()));
+		float ang1 = math::Abs(Angle(v0->P() - v1->P(), v2->P() - v1->P()));
+		float ang2 = M_PI - ang0 - ang1;
 		
 		float s01 = SquaredDistance(v1->P(), v0->P());
 		float s02 = SquaredDistance(v2->P(), v0->P());
 		
-		// voronoi cell of vertex i
-		if ((ang0 < M_PI/2) && (ang1 < M_PI/2) && (ang2 < M_PI/2)) // non obctuse
-			res.A += (s02 * (0.125 / tan(ang1)) + s01 * (0.125 / tan(ang2) ));
-		else {
-			VertexPointer obctvert;
-			
-			if(ang0 >= M_PI/2) obctvert = v0;
-			else if(ang1 >= M_PI/2) obctvert = v1;
-			else if(ang2 >= M_PI/2) obctvert = v2;
-			
-			// obctuse
-			if(obctvert == v0) {
-				TriangleType triangle(v0->P(), v1->P(), v2->P());
-				res.A += (0.5f * DoubleArea(triangle) -
-				         (s01 * 0.125 * tan(ang1) + s02 * 0.125 * tan(ang2)) );
-			}
-			else {
-				float e = SquaredDistance(v0->P(), obctvert->P());
-				res.A += (e * 0.125 * tan(ang0));
-			}
-		}
+		// voronoi cell of vertex
+		if (ang0 >= M_PI/2) {
+			TriangleType triangle(v0->P(), v1->P(), v2->P());
+			res.A += (0.5f * DoubleArea(triangle) -
+					(s01 * tan(ang1) + s02 * tan(ang2)) / 8.0 );
+		} else if (ang1 >= M_PI/2)
+			res.A += (s01 * tan(ang0)) / 8.0;
+		else if (ang2 >= M_PI/2)
+			res.A += (s02 * tan(ang0) / 8.0);
+		else // non obctuse triangle
+			res.A += ((s02 / tan(ang1)) + (s01 / tan(ang2))) / 8.0;
 		
 		res.K += ang0;
 		
 		ang1 = math::Abs(Angle(fNormal, v1->N()));
 		ang2 = math::Abs(Angle(fNormal, v2->N()));
-		res.H += ( (Distance(v0->P(), v1->P()) / 2.0) * ang1 + 
-				   (Distance(v0->P(), v2->P()) / 2.0) * ang2 );
+		res.H += ( (math::Sqrt(s01) / 2.0) * ang1 + 
+				   (math::Sqrt(s02) / 2.0) * ang2 );
 		
 		return res;
 	}
@@ -159,16 +149,12 @@ public:
 	// temporary empty (flip is already done in constructor)
 	void Execute(TRIMESH_TYPE& m)
 	{
-		VertexPointer v0, v1, v2, v3;
 		int i = this->_pos.E();
 		FacePointer f1 = this->_pos.F();
 		int j = f1->FFi(i);
 		FacePointer f2 = f1->FFp(i);
-		
-		v0 = f1->V0(i);
-		v1 = f1->V1(i);
-		v2 = f1->V2(i);
-		v3 = f2->V2(j);
+		VertexPointer v0 = f1->V0(i), v1 = f1->V1(i),
+		              v2 = f1->V2(i), v3 = f2->V2(j);
 		
 		// save precomputed curvature in vertex quality
 		v0->Q() = _cv0;
diff --git a/src/fgt/filter_trioptimize/filter_trioptimize.cpp b/src/fgt/filter_trioptimize/filter_trioptimize.cpp
index fd8ef1e77..f00dd72ce 100644
--- a/src/fgt/filter_trioptimize/filter_trioptimize.cpp
+++ b/src/fgt/filter_trioptimize/filter_trioptimize.cpp
@@ -143,8 +143,7 @@ const int TriOptimizePlugin::getRequirements(QAction *action)
 			return MeshModel::MM_FACETOPO |
 			       MeshModel::MM_VERTFACETOPO | 
 			       MeshModel::MM_VERTMARK | 
-			       MeshModel::MM_BORDERFLAG |
-			       MeshModel::MM_CURV;
+			       MeshModel::MM_BORDERFLAG;
 		case FP_NEAR_LAPLACIAN_SMOOTH:
 			return MeshModel::MM_BORDERFLAG;
 	}
@@ -195,11 +194,11 @@ const TriOptimizePlugin::FilterClass TriOptimizePlugin::getClass(QAction *action
 // - the string shown in the dialog 
 // - the default value
 // - a possibly long string describing the meaning of that parameter (shown as a popup help in the dialog)
-void TriOptimizePlugin::initParameterSet(QAction *action, MeshModel &/*m*/,
+void TriOptimizePlugin::initParameterSet(QAction *action, MeshModel &m,
                                          FilterParameterSet & parlst)
 {
 	if (ID(action) == FP_EDGE_FLIP) {
-		parlst.addBool("selection", false, tr("Update selection"),
+		parlst.addBool("selection", m.cm.sfn > 0, tr("Update selection"),
 				tr("Apply edge flip optimization on selected faces only"));
 		
 		parlst.addBool("cflips", true, tr("Curvature flips"),
@@ -284,8 +283,6 @@ bool TriOptimizePlugin::applyFilter(QAction *filter, MeshModel &m,
 		vcg::tri::UpdateTopology<CMeshO>::FaceFace(m.cm);
 		vcg::tri::UpdateFlags<CMeshO>::FaceBorderFromFF(m.cm);
 		
-		vcg::tri::UpdateTopology<CMeshO>::TestFaceFace(m.cm);
-		
 		vcg::LocalOptimization<CMeshO> optimiz(m.cm);
 		float pthr = par.getAbsPerc("pthreshold");
 		time_t start = clock();