diff --git a/EGkTriangle3d.h b/EGkTriangle3d.h
index db8b752..4bf0a3d 100644
--- a/EGkTriangle3d.h
+++ b/EGkTriangle3d.h
@@ -23,7 +23,7 @@
 class Triangle3d
 {
    public :
-      Triangle3d( void) : m_nFlag( 0)
+      Triangle3d( void) : m_nGrade( 0)
               { m_nAttr[0] = 0 ;  m_nAttr[1] = 0 ; m_nAttr[2] = 0 ; }
       void Set( const Point3d& ptP0, const Point3d& ptP1, const Point3d& ptP2)
               { m_ptP[0] = ptP0 ; m_ptP[1] = ptP1 ; m_ptP[2] = ptP2 ; m_vtN.Set( 0, 0, 0) ; }
@@ -35,8 +35,8 @@ class Triangle3d
                 m_ptP[nInd] = ptV ;
                 return true ;
               }
-      bool SetFlag( int nFlag) 
-              { m_nFlag = nFlag ;
+      bool SetGrade( int nFlag) 
+              { m_nGrade = nFlag ;
                 return true ;
               }
       bool SetAttrib( int nInd, int nVal) 
@@ -112,8 +112,8 @@ class Triangle3d
                 else
                    return m_ptP[2] ;
               }
-      int GetFlag( void) const 
-              { return m_nFlag ; }
+      int GetGrade( void) const 
+              { return m_nGrade ; }
       int GetAttrib( int nInd) const
               { if ( nInd >= 0  &&  nInd < 3)
                    return m_nAttr[nInd] ;
@@ -139,10 +139,10 @@ class Triangle3d
                    return ( (std::max)( dSqDistA, (std::max)( dSqDistB, dSqDistC)) / dTwoArea) ;
               }
 
-   private :
+   protected :
       Point3d  m_ptP[3] ;
       Vector3d m_vtN ;
-      int      m_nFlag ;
+      int      m_nGrade ;
       int      m_nAttr[3] ;
 } ;
 
@@ -156,6 +156,14 @@ typedef std::vector<TRIA3DLIST>  TRIA3DLISTVECTOR ;  // vettore di liste di Tria
 // Flags indicanti se i lati sono parte del contorno di un poligono di pił triangoli
 class TriFlags3d
 {
+   public :
+      TriFlags3d( void)
+         { bFlag[0] = true ; bFlag[1] = true ; bFlag[2] = true ; }
+      TriFlags3d( bool bF)
+         { bFlag[0] = bF ; bFlag[1] = bF ; bFlag[2] = bF ; }
+      TriFlags3d( bool bF0, bool bF1, bool bF2)
+         { bFlag[0] = bF0 ; bFlag[1] = bF1 ; bFlag[2] = bF2 ; }
+
    public :
       bool bFlag[3] ;
 } ;
@@ -164,10 +172,82 @@ class TriFlags3d
 // Normali sui vertici, ottenute mediando opportunamente coi triangoli vicini
 class TriNormals3d
 {
+   public :
+      TriNormals3d( void)
+         {}
+      TriNormals3d( const Vector3d& vtNrm)
+         { vtN[0] = vtNrm ; vtN[1] = vtNrm ; vtN[2] = vtNrm ; }
+      TriNormals3d( const Vector3d& vtN0, const Vector3d& vtN1, const Vector3d& vtN2)
+         { vtN[0] = vtN0 ; vtN[1] = vtN1 ; vtN[2] = vtN2 ; }
+
    public :
       Vector3d vtN[3] ;
 } ;
 
+//-----------------------------------------------------------------------------
+// Classe derivata da Triangle3d che include anche i flag dei lati e le normali dei vertici
+class Triangle3dEx : public Triangle3d
+{
+   public :
+      Triangle3dEx( void)
+              {}
+      Triangle3dEx( const Triangle3d& trTria)
+              { *(static_cast<Triangle3d*>(this)) = trTria ;
+                for ( int i = 0 ; i < 3 ; ++ i)
+                   m_triN.vtN[i] = m_vtN ;
+              }
+      bool SetEdgeFlag( int nInd, bool bVal)
+              { if ( nInd < 0  ||  nInd >= 3)
+                   return false ;
+                m_triF.bFlag[nInd] = bVal ;
+                return true ;
+              }
+      bool GetEdgeFlag( int nInd) const
+              { if ( nInd >= 0  &&  nInd < 3)
+                   return m_triF.bFlag[nInd] ;
+                else if ( nInd < 0)
+                   return m_triF.bFlag[0] ;
+                else
+                   return m_triF.bFlag[2] ;
+              }
+      const TriFlags3d& GetTriFlags( void) const
+              { return m_triF ; }
+      bool SetVertexNorm( int nInd, const Vector3d& vtN)
+              { if ( nInd < 0  ||  nInd >= 3)
+                   return false ;
+                m_triN.vtN[nInd] = vtN ;
+                return true ;
+              }
+      const Vector3d& GetVertexNorm( int nInd) const
+              { if ( nInd >= 0  &&  nInd < 3)
+                   return m_triN.vtN[nInd] ;
+                else if ( nInd < 0)
+                   return m_triN.vtN[0] ;
+                else
+                   return m_triN.vtN[2] ;
+              }
+      const TriNormals3d& GetTriNormals( void) const
+              { return m_triN ; }
+      bool Validate( bool bOverwrite = false)
+              { if ( ! Triangle3d::Validate( bOverwrite))
+                   return false ;
+                for ( int i = 0 ; i < 3 ; ++ i) {
+                   if ( m_triN.vtN[i].IsZero())
+                      m_triN.vtN[i] = m_vtN ;
+                }
+                return true ;
+              }
+   private :
+     TriFlags3d   m_triF ;
+     TriNormals3d m_triN ;
+} ;
+
+//----------------------------------------------------------------------------
+// Raccolte di Triangle3dEx
+typedef std::vector<Triangle3dEx>  TRIA3DEXVECTOR ;      // vettore di Triangle3dEx
+typedef std::list<Triangle3dEx>    TRIA3DEXLIST ;        // lista di Triangle3dEx
+typedef std::vector<TRIA3DEXLIST>  TRIA3DEXLISTVECTOR ;  // vettore di liste di Triangle3dEx
+
 //-----------------------------------------------------------------------------
 enum PlaneType { PL_NULL = 0,
                  PL_XY = 1,
diff --git a/EGkVolZmap.h b/EGkVolZmap.h
index 7a1a775..8326460 100644
--- a/EGkVolZmap.h
+++ b/EGkVolZmap.h
@@ -30,12 +30,12 @@ class __declspec( novtable) IVolZmap : public IGeoObj
       virtual bool Create( const Point3d& ptO, double dDimX, double dDimY, double dDimZ, double dPrec, bool bTriDex) = 0 ;
       virtual bool CreateFromFlatRegion( const ISurfFlatRegion& Surf, double dDimZ, double dPrec, bool bTriDex) = 0 ;
       virtual bool CreateFromTriMesh( const ISurfTriMesh& Surf, double dPrec, bool bTriDex) = 0 ;
-      virtual bool GetAllTriangles( TRIA3DLIST& lstTria) const = 0 ;
+      virtual bool GetAllTriangles( TRIA3DEXLIST& lstTria) const = 0 ;
       virtual int  GetBlockCount( void) const = 0 ;
       virtual bool GetVolume( double& dVol) const = 0 ;
       virtual int  GetPartCount( void) const = 0 ;
       virtual bool GetPartVolume( int nPart, double& dVol) const = 0 ;
-      virtual bool GetTriangles( bool bAllBlocks, INTVECTOR& nModifiedBlocks, TRIA3DLISTVECTOR& vLstTria) const ;
+      virtual bool GetTriangles( bool bAllBlocks, INTVECTOR& nModifiedBlocks, TRIA3DEXLISTVECTOR& vLstTria) const ;
       virtual bool GetDexelLines( int nDir, int nPos1, int nPos2, POLYLINELIST& lstPL) const = 0 ;
       virtual bool SetTolerances( double dLinTol, double dAngTolDeg = 90) = 0 ;
       virtual bool SetStdTool( const std::string& sToolName, double dH, double dR, double dCornR, int nFlag) = 0 ;