diff --git a/OffsetCurve3d.cpp b/OffsetCurve3d.cpp
index 50cc9c3..495d92d 100644
--- a/OffsetCurve3d.cpp
+++ b/OffsetCurve3d.cpp
@@ -25,10 +25,11 @@
 
 using namespace std ;
 
-#define SAVECVRORIG 0
+#define SAVECRVORIG 0
 #define SAVEOFFDIR 0
 #define SAVECYL 0
-#if SAVECVRORIG || SAVEOFFDIR || SAVECYL
+#define SAVEOFFSET 0
+#if SAVECRVORIG || SAVEOFFDIR || SAVECYL  || SAVEOFFSET
    #include "/EgtDev/Include/EGkColor.h"
    #include "/EgtDev/Include/EGkGeoVector3d.h"
    vector<IGeoObj*> vGeo ;
@@ -87,7 +88,7 @@ OffsetCurve3d::Make( const PolyLine& PL, const VCT3DVECTOR& vOffDir, double dOff
    if ( ! pCrv->FromPolyLine( PL))
       return false ;
     
-#if SAVECVRORIG  || SAVEOFFDIR
+#if SAVECRVORIG  || SAVEOFFDIR
    vGeo.clear() ;
    vCol.clear() ;
 
@@ -103,6 +104,9 @@ OffsetCurve3d::Make( const PolyLine& PL, const VCT3DVECTOR& vOffDir, double dOff
             vCol.push_back( BLUE) ;
          }
    #endif
+   #if ! SAVECYL  &&  ! SAVEOFFSET
+         SaveGeoObj( vGeo, vCol, "C:\\Temp\\curve offset 3d\\crvoffset.nge") ;
+   #endif
 #endif
 
    // verifico se la curva è un segmento di retta
@@ -233,6 +237,7 @@ OffsetCurve3d::Make( const PolyLine& PL, const VCT3DVECTOR& vOffDir, double dOff
       double dProj = 1 ;
       if ( vtDirPrevOff.IsValid())
          dProj = vtDirCurrOff * vtDirPrevOff ;
+      // prima di inserirlo controllo che il tratto non torni indietro
       if ( dProj > - 0.5  ||  vFlag[i] == OffsetCurve3d::AngType::ANG_SMOOTH_CONC) {
          // aggiungo tratto
          ICurveLine* pCL = CreateBasicCurveLine() ;
@@ -261,18 +266,19 @@ OffsetCurve3d::Make( const PolyLine& PL, const VCT3DVECTOR& vOffDir, double dOff
    if ( ! AdjustConcavePartsInPath( pCrv, vOffsetCrvs, dOffDist))
       return false ;
 
-#if SAVECVRORIG || SAVEOFFDIR || SAVECYL
-   for ( int i = 0 ; i < ssize( vOffsetCrvs) ; ++i) {
-      vGeo.push_back( vOffsetCrvs[i].pCrv->Clone()) ;
-      if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_SMOOTH_CONC)
-         vCol.push_back( GREEN) ;
-      else if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_STR)
-         vCol.push_back( PURPLE) ;
-      else if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_CVEX)
-         vCol.push_back( RED) ;
-   }
+#if SAVEOFFSET  || SAVECYL
+   #if SAVEOFFSET
+      for ( int i = 0 ; i < ssize( vOffsetCrvs) ; ++i) {
+         vGeo.push_back( vOffsetCrvs[i].pCrv->Clone()) ;
+         if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_SMOOTH_CONC)
+            vCol.push_back( GREEN) ;
+         else if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_STR)
+            vCol.push_back( PURPLE) ;
+         else if ( vOffsetCrvs[i].nFlag == OffsetCurve3d::AngType::ANG_CVEX)
+            vCol.push_back( RED) ;
+      }
+   #endif
    SaveGeoObj( vGeo, vCol, "C:\\Temp\\curve offset 3d\\crvoffset.nge") ;
-   return true ;
 #endif 
 
    PtrOwner<ICurveComposite> pCrvOffset( CreateBasicCurveComposite()) ;
@@ -387,7 +393,7 @@ IsPointInsideCylinder( const Point3d& ptTest, const Cyl& offCyl, double dLinTol)
 bool
 AdjustConcavePartsInPath( const ICurveComposite* pCrv, vOffsetSeg& vOffsetCrvs, double dRad)
 {
-   const double dLinTol = 5 * EPS_SMALL ;
+   const double dLinTol = 10 * EPS_SMALL ;
    INTVECTOR vErase ;
    for ( int i = 0 ; i < ssize( vOffsetCrvs) ; ++i) {
       int nFlag = vOffsetCrvs[i].nFlag ;
@@ -414,7 +420,7 @@ AdjustConcavePartsInPath( const ICurveComposite* pCrv, vOffsetSeg& vOffsetCrvs,
             vCyl.emplace_back( ptStart, vtHeight, dHeight, dRad, dLinTol) ;
 #if SAVECYL
             CurveArc ca ; ca.Set( ptStart, vtHeight, dRad) ;
-            ISurfTriMesh* pSurfTm = GetSurfTriMeshByExtrusion( &ca, vtHeight, false, 2 * EPS_SMALL) ;
+            ISurfTriMesh* pSurfTm = GetSurfTriMeshByExtrusion( &ca, vtHeight * dHeight, false, 2 * EPS_SMALL) ;
             vGeo.push_back( pSurfTm) ;
             vCol.push_back( LGRAY) ;
 #endif
@@ -442,6 +448,12 @@ AdjustConcavePartsInPath( const ICurveComposite* pCrv, vOffsetSeg& vOffsetCrvs,
                if ( bToErase) {                 
                   bErasedSomePart = true ;
                   bErasedPrev = true ;
+                  // se avevo un'interruzione nella zona da modificare, la colmo
+                  if ( ! vInters.empty()  && vInters.back() != vLines[j-1]) {
+                     // aggiungo tutti i precedenti che mancano
+                     for ( int h = vInters.back() + 1 ; h < vLines[j] ; ++h)
+                        vInters.push_back( h) ;
+                  }
                   vInters.push_back( vLines[j]) ;
                   if ( j < ssize( vLines) - 1)
                      vInters.push_back( vLines[j+1]) ;
diff --git a/ProjectCurveSurf.cpp b/ProjectCurveSurf.cpp
index dc207ba..30151ef 100644
--- a/ProjectCurveSurf.cpp
+++ b/ProjectCurveSurf.cpp
@@ -81,24 +81,34 @@ AddPointsOnCorners( PNT5AXVECTOR& vPt5ax)
             Point3d ptInt ;
             if ( IntersLinePlane( ptEdge, vtEdge, 1, plPlane3, ptInt, false) == ILPT_YES) {
               // verifico se spigolo convesso o concavo
-               bool bConvex = (vPt5ax[i].ptP - vPt5ax[j].ptP) * vPt5ax[j].vtDir1 < 0 ;
-               bool bValidInters = true ;
+               double dProjPrev = ( vPt5ax[i].ptP - vPt5ax[j].ptP) * vPt5ax[j].vtDir1 ;
+               double dProjCurr = ( vPt5ax[j].ptP - vPt5ax[i].ptP) * vPt5ax[i].vtDir1 ;
+               bool bConvex = ( abs( dProjCurr) > abs( dProjPrev) ? dProjCurr < 0 : dProjPrev < 0) ;
+               bool bValidIntersAfterJ = true ;
+               bool bValidIntersBeforeI = true ;
                if ( i > 2) {
-                  int k = i - 2 ;
-                  // verifico la concavità anche tornando indietro lungo la linea
-                  if ( ( ( vPt5ax[k].ptP - vPt5ax[j].ptP) * vPt5ax[i].vtDir1 < 0) != bConvex) {
-                     LOG_WARN( GetEGkLogger(), "La superficie su cui si sta proiettando la curva ha delle normali incoerenti")
-                     return false ;
-                  }
                   // verifico che l'intersezione sia tra i e j e non prima di j
-                  bValidInters = ( ptInt - vPt5ax[j].ptP) * ( vPt5ax[j].ptP - vPt5ax[k].ptP) > 0 ;
+                  int k = i - 2 ;
+                  bValidIntersAfterJ = ( ptInt - vPt5ax[j].ptP) * ( vPt5ax[j].ptP - vPt5ax[k].ptP) > 0 ;
                }
+               if ( i < ssize( vPt5ax) - 1) {
+                  // verifico anche che l'intersezione non sia dopo i
+                  int h = i + 1 ;
+                  bValidIntersBeforeI = ( ptInt - vPt5ax[i].ptP) * ( vPt5ax[h].ptP - vPt5ax[i].ptP) < 0 ;
+               }
+               bool bValidInters = ( bValidIntersAfterJ  &&  bValidIntersBeforeI) ;
               // se convesso, metto due punti con direzione appena prima e appena dopo
                if ( bConvex) {
                   Vector3d vtLine1 = ptInt - vPt5ax[j].ptP ; double dLen1 = vtLine1.Len() ;
                   Vector3d vtLine2 = vPt5ax[i].ptP - ptInt ; double dLen2 = vtLine2.Len() ;
-                  if ( dLen1 > 10 * EPS_SMALL  &&  bValidInters) {
+                  if ( dLen1 > 10 * EPS_SMALL  &&  bValidIntersAfterJ) {
                      Point5ax Pt5ax ;
+                     if ( bValidInters)
+                        Pt5ax.ptP = ptInt - vtLine1 / dLen1 * 2 * EPS_SMALL ;
+                     else {
+                        Vector3d vtNewLine = vPt5ax[i].ptP - vPt5ax[j].ptP ; vtNewLine.Normalize() ;
+                        Pt5ax.ptP =  vPt5ax[i].ptP - vtNewLine * 2 * EPS_SMALL ;
+                     }
                      Pt5ax.vtDir1 = vPt5ax[j].vtDir1 ;
                      Pt5ax.vtDir2 = vPt5ax[j].vtDir2 ;
                      Pt5ax.vtDirU = vPt5ax[j].vtDirU ;
@@ -110,7 +120,7 @@ AddPointsOnCorners( PNT5AXVECTOR& vPt5ax)
                   }
                   else
                      vPt5ax[j].nFlag = P5AX_CVEX ;
-                  if ( dLen2 > 10 * EPS_SMALL) {
+                  if ( dLen2 > 10 * EPS_SMALL  && bValidIntersBeforeI) {
                      Point5ax Pt5ax ;
                      if ( bValidInters)
                         Pt5ax.ptP = ptInt + vtLine2 / dLen2 * 2 * EPS_SMALL ;