diff --git a/EgtGraphics.rc b/EgtGraphics.rc
index fe15792..6b79b1c 100644
Binary files a/EgtGraphics.rc and b/EgtGraphics.rc differ
diff --git a/SceneBasic.cpp b/SceneBasic.cpp
index 2fbc448..01238a0 100644
--- a/SceneBasic.cpp
+++ b/SceneBasic.cpp
@@ -725,7 +725,7 @@ Scene::Draw( void)
      // disegno le geometrie del DB
       // prima passata per superfici con illuminazione abilitata
       glEnable( GL_POLYGON_OFFSET_FILL) ;
-      glPolygonOffset( 1.0, 1.0) ;
+      glPolygonOffset( 0.75, 0.75) ;
       glEnable( GL_LIGHTING) ;
       DrawGroup( GDB_ID_ROOT, 1, MdStMk( GDB_MD_STD, GDB_ST_ON, GDB_MK_OFF)) ;
       glDisable( GL_POLYGON_OFFSET_FILL) ;
diff --git a/SceneGeom.cpp b/SceneGeom.cpp
index 93dca37..5d381ae 100644
--- a/SceneGeom.cpp
+++ b/SceneGeom.cpp
@@ -169,7 +169,7 @@ Scene::DrawGeoObj( const IGdbIterator& iIter, int nPass, MdStMk siObj)
       if ( m_bNewWay  &&  nGeoType == SRF_TRIMESH) {
          const ISurfTriMesh* pSTM = GetSurfTriMesh( pGeoObj) ;
          if ( pSTM != nullptr  &&  pSTM->GetTriangleNum() > N_MIN_TRIA_NEWWAY)
-            m_bNewWay = true ;
+            bNewWay = true ;
       }  
       ObjEGrGraphics* pGraphics = CreateObjEGrGraphics( bNewWay) ;
       if ( pGraphics == nullptr)
@@ -416,16 +416,19 @@ CalcCurveTailMark( const Vector3d& vtRef, const PolyLine& plCrv, PolyLine& plMar
          break ;
       Vector3d vtNxDir = ptP2 - ptP1 ;
       vtNxDir.Normalize() ;
-      if ( ( vtDir * vtNxDir) > cos( 30 * DEGTORAD)) {
-         vtDir = ptP1 - ptTail ;
-         dLen = vtDir.Len() ;
-         vtDir /= dLen ;
-      }
+      if ( ( vtDir * vtNxDir) > cos( 30 * DEGTORAD))
+         dLen = (ptP1 - ptTail).Len() ;
       else
          break ;
    }
+  // recupero lunghezza del percorso
+   double dLenRef = 0 ;
+   plCrv.GetApproxLength( dLenRef) ;
+  // lunghezza della freccia
   // calcolo dimensioni traverso
-   double dLenTr = dLen ;
+   const double TR_COEFF = 0.6 ;
+   const double LEN_COEFF = 0.15 ;
+   double dLenTr = TR_COEFF * min( LEN_COEFF * dLenRef, dLen)  ;
    if ( dLenTr > MAX_LEN_TR)
       dLenTr = MAX_LEN_TR ;
    else if ( dLenTr < MIN_LEN_TR)
@@ -488,11 +491,8 @@ CalcCurveTipArrow( const Vector3d& vtRef, const PolyLine& plCrv, PolyLine& plArr
          break ;
       Vector3d vtPrDir = ptP2 - ptP1 ;
       vtPrDir.Normalize() ;
-      if ( ( vtDir * vtPrDir) > cos( 30 * DEGTORAD)) {
-         vtDir = ptTip - ptP1 ;
-         dLen = vtDir.Len() ;
-         vtDir /= dLen ;
-      }
+      if ( ( vtDir * vtPrDir) > cos( 30 * DEGTORAD))
+         dLen = (ptTip - ptP1).Len() ;
       else
          break ;
    }
@@ -500,7 +500,7 @@ CalcCurveTipArrow( const Vector3d& vtRef, const PolyLine& plCrv, PolyLine& plArr
    double dLenRef = 0 ;
    plCrv.GetApproxLength( dLenRef) ;
   // lunghezza della freccia
-   const double LEN_COEFF = 0.25 ;
+   const double LEN_COEFF = 0.15 ;
    double dLenArr = min( LEN_COEFF * dLenRef, dLen) ;
    if ( dLenArr > MAX_LEN_ARR)
       dLenArr = MAX_LEN_ARR ;
diff --git a/SceneGrid.cpp b/SceneGrid.cpp
index c4c21e4..853f061 100644
--- a/SceneGrid.cpp
+++ b/SceneGrid.cpp
@@ -66,7 +66,7 @@ Scene::DrawGrid( void)
   // semi-estensione della griglia
    float dExt = float( m_nExtSstep * m_dSnapStep) ;
   // abbassamento in Z per evitare sovrapposizioni con geometria
-   const float Z_DOWN = float( - 0.01) ;
+   const float Z_DOWN = float( - 0.0005) ;
 
   // se richiesto, disegno la griglia
    if ( m_bShowGrid) {
diff --git a/SceneSnap.cpp b/SceneSnap.cpp
index b1bb3d1..e5e6517 100644
--- a/SceneSnap.cpp
+++ b/SceneSnap.cpp
@@ -198,14 +198,25 @@ Scene::GetSelectedSnapPoint( int nSnap, const Point3d& ptWin, int nW, int nH, Po
             if ( DistPointCurve( ptRef, *pCrvCompo).GetParamAtMinDistPoint( 0, dPar, nFlag))
                nCrv = static_cast<int>( dPar) ;
          }
+        // vettore estrusione e spessore della curva composita
+         Vector3d vtExtr = V_NULL ;
+         pCrvCompo->GetExtrusion( vtExtr) ;
+         double dThick = 0 ;
+         pCrvCompo->GetThickness( dThick) ;
         // ciclo sulle curve elementari
          int nCont = 0 ;
          const ICurve* pCrv = pCrvCompo->GetFirstCurve() ;
          while ( pCrv != nullptr) {
+           // imposto estrusione e spessore della curva composita
+            (const_cast<ICurve*>(pCrv))->SetExtrusion( vtExtr) ;
+            (const_cast<ICurve*>(pCrv))->SetThickness( dThick) ;
            // verifico i punti notevoli della curva
             if ( nCont == nCrv  &&
                  TestCurveSnapPoints( nSnap, ptWinZ, nId, frEnt, pCrv, dMinSqDist, ptSel))
                bFound = true ;
+           // ripristino valori originali
+            (const_cast<ICurve*>(pCrv))->SetExtrusion( V_NULL) ;
+            (const_cast<ICurve*>(pCrv))->SetThickness( 0) ;
            // passo alla successiva
             ++ nCont ;
             pCrv = pCrvCompo->GetNextCurve() ;