diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index 625909e..8881ee7 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -383,13 +383,13 @@ CurveComposite::FromPolyArc( const PolyArc& PA)
 
 //----------------------------------------------------------------------------
 bool
-CurveComposite::PolygonCenterCorner( int nSides, const Point3d& ptCen, const Point3d& ptCorner)
+CurveComposite::PolygonCenterCorner( int nSides, const Point3d& ptCen, const Point3d& ptCorner, const Vector3d& vtN)
 {
   // verifico lo stato
    if ( m_nCounter != 0  ||  m_nStatus != TO_VERIFY)
       return false ;
-  // almeno 3 lati
-   if ( nSides < 3)
+  // almeno 3 lati e normale ben definita
+   if ( nSides < 3  ||  vtN.IsSmall())
       return false ;
 
   // angolo al centro corrispondente ad un lato
@@ -403,7 +403,7 @@ CurveComposite::PolygonCenterCorner( int nSides, const Point3d& ptCen, const Poi
    for ( int i = 1 ; i <= nSides ; ++ i) {
      // calcolo il secondo punto del lato
       ptEnd = ptStart ;
-      ptEnd.Rotate( ptCen, Z_AX, dCosAng, dSinAng) ;
+      ptEnd.Rotate( ptCen, vtN, dCosAng, dSinAng) ;
      // se primo lato, verifico che la lunghezza sia superiore al minimo
       if ( i == 1) {
          if ( AreSamePointApprox( ptStart, ptEnd))
@@ -431,36 +431,36 @@ CurveComposite::PolygonCenterCorner( int nSides, const Point3d& ptCen, const Poi
 
 //----------------------------------------------------------------------------
 bool
-CurveComposite::PolygonCenterMidSide( int nSides, const Point3d& ptCen, const Point3d& ptMidSide)
+CurveComposite::PolygonCenterMidSide( int nSides, const Point3d& ptCen, const Point3d& ptMidSide, const Vector3d& vtN)
 {
   // verifico lo stato
    if ( m_nCounter != 0  ||  m_nStatus != TO_VERIFY)
       return false ;
-  // almeno 3 lati
-   if ( nSides < 3)
+  // almeno 3 lati e normale ben definita
+   if ( nSides < 3  ||  vtN.IsSmall())
       return false ;
 
   // calcolo la posizione del corner
    double dHalfCentSideAngDeg = ANG_FULL / ( 2 * nSides) ;
    double dCoeff = tan( dHalfCentSideAngDeg * DEGTORAD) ;
    Vector3d vtDir = ptCen - ptMidSide ;
-   vtDir.z = 0 ;
-   vtDir.Rotate( Z_AX, 0, 1) ;
+   vtDir -= ( vtDir * vtN) * vtN / vtN.SqLen() ;
+   vtDir.Rotate( vtN, 0, 1) ;
    Point3d ptCorner = ptMidSide + vtDir * dCoeff ;
 
   // ora costruisco come poligono con centro e corner
-   return PolygonCenterCorner( nSides, ptCen, ptCorner) ;
+   return PolygonCenterCorner( nSides, ptCen, ptCorner, vtN) ;
 }
 
 //----------------------------------------------------------------------------
 bool
-CurveComposite::PolygonSide( int nSides, const Point3d& ptStart, const Point3d& ptEnd)
+CurveComposite::PolygonSide( int nSides, const Point3d& ptStart, const Point3d& ptEnd, const Vector3d& vtN)
 {
   // verifico lo stato
    if ( m_nCounter != 0  ||  m_nStatus != TO_VERIFY)
       return false ;
-  // almeno 3 lati
-   if ( nSides < 3)
+  // almeno 3 lati e normale ben definita
+   if ( nSides < 3  ||  vtN.IsSmall())
       return false ;
   // verifico che la lunghezza sia superiore al minimo
    if ( AreSamePointApprox( ptStart, ptEnd))
@@ -470,12 +470,12 @@ CurveComposite::PolygonSide( int nSides, const Point3d& ptStart, const Point3d&
    double dHalfCentSideAngDeg = ANG_FULL / ( 2 * nSides) ;
    double dCoeff = 1 / ( 2 * tan( dHalfCentSideAngDeg * DEGTORAD)) ;
    Vector3d vtDir = ptEnd - ptStart ;
-   vtDir.z = 0 ;
-   vtDir.Rotate( Z_AX, 0, 1) ;
+   vtDir -= ( vtDir * vtN) * vtN / vtN.SqLen() ;
+   vtDir.Rotate( vtN, 0, 1) ;
    Point3d ptCen = Media( ptStart, ptEnd, 0.5) + vtDir * dCoeff ;
 
   // ora costruisco come poligono con centro e corner
-   return PolygonCenterCorner( nSides, ptCen, ptStart) ;
+   return PolygonCenterCorner( nSides, ptCen, ptStart, vtN) ;
 }
 
 //----------------------------------------------------------------------------
diff --git a/CurveComposite.h b/CurveComposite.h
index 4bc4927..0245d76 100644
--- a/CurveComposite.h
+++ b/CurveComposite.h
@@ -120,9 +120,9 @@ class CurveComposite : public ICurveComposite, public IGeoObjRW
       virtual bool FromSplit( const ICurve& cCrv, int nParts) ;
       virtual bool FromPolyLine( const PolyLine& PL) ;
       virtual bool FromPolyArc( const PolyArc& PA) ;
-      virtual bool PolygonCenterCorner( int nSides, const Point3d& ptCen, const Point3d& ptCorner) ;
-      virtual bool PolygonCenterMidSide( int nSides, const Point3d& ptCen, const Point3d& ptMidSide) ;
-      virtual bool PolygonSide( int nSides, const Point3d& ptStart, const Point3d& ptEnd) ;
+      virtual bool PolygonCenterCorner( int nSides, const Point3d& ptCen, const Point3d& ptCorner, const Vector3d& vtN) ;
+      virtual bool PolygonCenterMidSide( int nSides, const Point3d& ptCen, const Point3d& ptMidSide, const Vector3d& vtN) ;
+      virtual bool PolygonSide( int nSides, const Point3d& ptStart, const Point3d& ptEnd, const Vector3d& vtN) ;
       virtual int  GetCurveNumber( void) const
                       { return m_nCounter ; }
       virtual const ICurve* GetFirstCurve( void) const ;
diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index 0b16fa0..7a4ae79 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ
diff --git a/FontOs.cpp b/FontOs.cpp
index 2f1e885..1a531ad 100644
--- a/FontOs.cpp
+++ b/FontOs.cpp
@@ -60,8 +60,8 @@ OsFont::SetCurrFont( const string& sFont, int nWeight, bool bItalic,
    string sFontUp = sFont ;
    ToUpper( sFontUp) ;
 
-  // se il font non è già caricato
-   if (  m_sFont != sFontUp) {
+  // se il font non è già caricato o sono cambiati dei parametri di creazione
+   if (  m_sFont != sFontUp  ||  nWeight != m_nWeight  ||  bItalic != m_bItalic) {
      // pulisco la path del font
       m_sFont.clear() ;
      // cancello eventuale precedente font
diff --git a/GdbExecutor.cpp b/GdbExecutor.cpp
index 2d4f886..29e35fb 100644
--- a/GdbExecutor.cpp
+++ b/GdbExecutor.cpp
@@ -1952,15 +1952,15 @@ GdbExecutor::CurveCompoFromPolygon( const STRVECTOR& vsParams, int nType)
   // costruisco il poligono
    switch ( nType) {
    case POLYG_INSCR :
-      if ( ! pCrvCompo->PolygonCenterCorner( nNumLati, ptP1, ptP2))
+      if ( ! pCrvCompo->PolygonCenterCorner( nNumLati, ptP1, ptP2, Z_AX))
          return false ;
       break ;
    case POLYG_CIRC :
-      if ( ! pCrvCompo->PolygonCenterMidSide( nNumLati, ptP1, ptP2))
+      if ( ! pCrvCompo->PolygonCenterMidSide( nNumLati, ptP1, ptP2, Z_AX))
          return false ;
       break ;
    case POLYG_SIDE :
-      if ( ! pCrvCompo->PolygonSide( nNumLati, ptP1, ptP2))
+      if ( ! pCrvCompo->PolygonSide( nNumLati, ptP1, ptP2, Z_AX))
          return false ;
       break ;
    default :
diff --git a/GeomDB.cpp b/GeomDB.cpp
index 1f392dc..076398f 100644
--- a/GeomDB.cpp
+++ b/GeomDB.cpp
@@ -797,13 +797,13 @@ GeomDB::Copy( int nIdSou, int nIdDest, int nRefId, int nSonBeforeAfter, bool bGl
   // verifico esistenza del padre
    GdbGroup* pGroupSou = pGdOSou->GetParent() ;
    if ( pGroupSou == nullptr)
-      return false ;
+      return GDB_ID_NULL ;
 
   // cerco il padre di destinazione
    int nParentIdDest = (( nSonBeforeAfter == GDB_SON) ? nRefId : GetParentId( nRefId)) ;
    GdbGroup* pGroupDest = GetGdbGroup( nParentIdDest) ;
    if ( pGroupDest == nullptr)
-      return false ;
+      return GDB_ID_NULL ;
 
   // eseguo la copia
    PtrOwner<GdbObj> pGdODest( pGdOSou->Clone( nIdDest)) ;
@@ -893,6 +893,26 @@ GeomDB::Relocate( int nId, int nRefId, int nSonBeforeAfter, bool bGlob)
    return true ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GeomDB::ChangeId( int nId, int nNewId)
+{
+  // verifico nuovo Id
+   if ( ExistsObj( nNewId))
+      return false ;
+  // recupero l'oggetto
+   GdbObj* pGdO = GetGdbObj( nId) ;
+   if ( pGdO == nullptr)
+      return false ;
+  // elimino da mappa dei nomi vecchio Id e inserisco nuovo
+   m_IdManager.RemoveObj( nId) ;
+   m_IdManager.AddObj( nNewId, pGdO) ;
+  // lista selezionati e GdbIterator non richiedono modifiche
+  // cambio Id dell'oggetto
+   pGdO->m_nId = nNewId ;
+   return true ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GeomDB::Erase( int nId)
diff --git a/GeomDB.h b/GeomDB.h
index 7bbf1d9..3d51333 100644
--- a/GeomDB.h
+++ b/GeomDB.h
@@ -71,6 +71,7 @@ class GeomDB : public IGeomDB
                       { return Relocate( nId, nRefId, nSonBeforeAfter, false) ; }
       virtual bool RelocateGlob( int nId, int nRefId, int nSonBeforeAfter = GDB_SON)
                       { return Relocate( nId, nRefId, nSonBeforeAfter, true) ; }
+      virtual bool ChangeId( int nId, int nNewId) ;
       virtual bool Erase( int nId) ;
       virtual bool Translate( int nId, const Vector3d& vtMove) ;
       virtual bool TranslateGlob( int nId, const Vector3d& vtMove) ;