diff --git a/Attribs.cpp b/Attribs.cpp
index 2bdc1c1..898605f 100644
--- a/Attribs.cpp
+++ b/Attribs.cpp
@@ -240,6 +240,19 @@ Attribs::GetName( string& sName) const
    return false ;
 }
 
+//----------------------------------------------------------------------------
+bool
+Attribs::ExistsName( void) const
+{
+  // può essere solo la prima stringa 
+   STRLIST::const_iterator iIter ;
+   if ( ( iIter = m_slInfo.begin()) != m_slInfo.end()  &&
+        FindKey( *iIter, NAME))
+      return true ;
+   
+   return false ;
+}
+
 //----------------------------------------------------------------------------
 bool
 Attribs::RemoveName( void)
@@ -306,6 +319,24 @@ Attribs::GetInfo( const string& sKey, string& sVal) const
    return false ;
 }
 
+//----------------------------------------------------------------------------
+bool
+Attribs::ExistsInfo( const string& sKey) const
+{
+  // se chiave non valida, esco con errore
+   if ( ! IsValidString( sKey))
+      return false ;
+
+  // cerco una stringa con la chiave
+   STRLIST::const_iterator iIter ;
+   for ( iIter = m_slInfo.begin() ; iIter != m_slInfo.end() ; ++ iIter) {
+      if ( FindKey( *iIter, sKey))
+         return true ;
+   }
+
+   return false ;
+}
+
 //----------------------------------------------------------------------------
 bool
 Attribs::RemoveInfo( const string& sKey)
diff --git a/Attribs.h b/Attribs.h
index 84ec669..07e390e 100644
--- a/Attribs.h
+++ b/Attribs.h
@@ -82,9 +82,11 @@ class Attribs
               { return m_Color ; }
       bool SetName( const std::string& sName) ;
       bool GetName( std::string& sName) const ;
+      bool ExistsName( void) const ;
       bool RemoveName( void) ;
       bool SetInfo( const std::string& sKey, const std::string& sVal) ;
       bool GetInfo( const std::string& sKey, std::string& sVal) const ;
+      bool ExistsInfo( const std::string& sKey) const ;
       bool RemoveInfo( const std::string& sKey) ;
 
    private :
diff --git a/CurveArc.cpp b/CurveArc.cpp
index b603f78..86a9a79 100644
--- a/CurveArc.cpp
+++ b/CurveArc.cpp
@@ -95,6 +95,7 @@ CurveArc::Set( const Point3d& ptCen, const Vector3d& vtN, double dRad)
   // assegno e calcolo i dati
    m_PtCen = ptCen ;
    m_VtN = vtN ;
+   m_VtN.Normalize() ;
    Frame3d frF ;
    if ( ! frF.Set( ORIG, vtN))
       return false ;
diff --git a/CurveComposite.cpp b/CurveComposite.cpp
index 4dc5251..c5f801e 100644
--- a/CurveComposite.cpp
+++ b/CurveComposite.cpp
@@ -280,9 +280,10 @@ CurveComposite::FromPointBulgeVector( const UPNTVECTOR& vUPnt, const Vector3d& v
       return false ;
 
   // Creo le diverse curve semplici e le inserisco in quella composita
+   int iPrev = 0 ;
    for ( int i = 1 ; i < int( vUPnt.size()) ; ++i) {
      // se i punti della coppia coincidono, passo alla coppia successiva
-      if ( AreSamePointNear( vUPnt[i-1].second, vUPnt[i].second))
+      if ( AreSamePointNear( vUPnt[iPrev].second, vUPnt[i].second))
          continue ;
      // se retta
       if ( fabs( vUPnt[i-1].first) < EPS_SMALL) {
@@ -291,7 +292,7 @@ CurveComposite::FromPointBulgeVector( const UPNTVECTOR& vUPnt, const Vector3d& v
          if ( ! ::IsValid( pCrvLine))
             return false ;
         // setto la linea
-         if ( ! pCrvLine->Set( vUPnt[i-1].second, vUPnt[i].second))
+         if ( ! pCrvLine->Set( vUPnt[iPrev].second, vUPnt[i].second))
             return false ;
         // inserisco la linea nella curva composta
          if ( ! AddSimpleCurve( ::Release( pCrvLine)))
@@ -304,12 +305,14 @@ CurveComposite::FromPointBulgeVector( const UPNTVECTOR& vUPnt, const Vector3d& v
          if ( ! ::IsValid( pCrvArc))
             return false ;
          // setto l'arco
-         if ( ! pCrvArc->Set2PNB( vUPnt[i-1].second, vUPnt[i].second, vtN, vUPnt[i-1].first))
+         if ( ! pCrvArc->Set2PNB( vUPnt[iPrev].second, vUPnt[i].second, vtN, vUPnt[i-1].first))
             return false ;
         // inserisco l'arco nella curva composta
          if ( ! AddSimpleCurve( Release( pCrvArc)))
             return false ;
       }
+     // aggiorno indice punto ultimo inserito
+      iPrev = i ;
    }
 
    return true ;
diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index b0ef58a..82ec3a5 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ
diff --git a/GdbIterator.cpp b/GdbIterator.cpp
index f2a10df..30d66a8 100644
--- a/GdbIterator.cpp
+++ b/GdbIterator.cpp
@@ -303,6 +303,21 @@ GdbIterator::GetGroupGlobFrame( Frame3d& frGlob) const
    return pGdbGroup->GetGlobFrame( frGlob) ;
 }
 
+//----------------------------------------------------------------------------
+int
+GdbIterator::GetGroupObjs( void) const
+{
+   if ( m_pGDB == nullptr  ||  m_pCurrObj == nullptr)
+      return 0 ;
+
+   GdbGroup* pGdbGroup ;
+   if ( ( pGdbGroup = GetGdbGroup( m_pCurrObj)) == nullptr)
+      return 0 ;
+
+  // restituisco il numero di nodi (figli)
+   return pGdbGroup->GetObjCount() ;
+}
+
 //----------------------------------------------------------------------------
 int
 GdbIterator::GetId( void) const
@@ -683,6 +698,17 @@ GdbIterator::GetName( string& sName) const
    return m_pCurrObj->GetName( sName) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GdbIterator::ExistsName( void) const
+{
+   if ( m_pGDB == nullptr  ||  m_pCurrObj == nullptr)
+      return false ;
+
+  // verifico esistenza del nome
+   return m_pCurrObj->ExistsName() ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GdbIterator::RemoveName( void)
@@ -716,6 +742,17 @@ GdbIterator::GetInfo( const string& sKey, string& sInfo) const
    return m_pCurrObj->GetInfo( sKey, sInfo) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GdbIterator::ExistsInfo( const string& sKey) const
+{
+   if ( m_pGDB == nullptr  ||  m_pCurrObj == nullptr)
+      return false ;
+
+  // verifico l'esistenza dell'Info
+   return m_pCurrObj->ExistsInfo( sKey) ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GdbIterator::RemoveInfo( const string& sKey)
diff --git a/GdbIterator.h b/GdbIterator.h
index ac69182..9208e98 100644
--- a/GdbIterator.h
+++ b/GdbIterator.h
@@ -39,6 +39,7 @@ class GdbIterator : public IGdbIterator
       virtual IGeoFrame3d* GetGeoFrame( void) ;
       virtual bool GetGroupFrame( Frame3d& frGlob) const ;
       virtual bool GetGroupGlobFrame( Frame3d& frGlob) const ;
+      virtual int  GetGroupObjs( void) const ;
       virtual int  GetId( void) const ;
       virtual int  GetParentId( void) const ;
       virtual bool GetGlobFrame( Frame3d& frGlob) const ;
@@ -72,9 +73,11 @@ class GdbIterator : public IGdbIterator
       virtual bool GetCalcMaterial( Color& cCol) const ;
       virtual bool SetName( const std::string& sName) ;
       virtual bool GetName( std::string& sName) const ;
+      virtual bool ExistsName( void) const ;
       virtual bool RemoveName( void) ;
       virtual bool SetInfo( const std::string& sKey, const std::string& sInfo) ;
       virtual bool GetInfo( const std::string& sKey, std::string& sInfo) const ;
+      virtual bool ExistsInfo( const std::string& sKey) const ;
       virtual bool RemoveInfo( const std::string& sKey) ;
 
    public :
diff --git a/GdbObj.cpp b/GdbObj.cpp
index 416ce9a..db3b1c2 100644
--- a/GdbObj.cpp
+++ b/GdbObj.cpp
@@ -664,6 +664,18 @@ GdbObj::GetName( string& sName) const
    return m_pAttribs->GetName( sName) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GdbObj::ExistsName( void) const
+{
+  // se non ci sono attributi
+   if ( m_pAttribs == nullptr)
+      return false ;
+
+  // restituisco il nome
+   return m_pAttribs->ExistsName() ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GdbObj::RemoveName( void)
@@ -684,7 +696,7 @@ GdbObj::SetInfo( const string& sKey, const string& sInfo)
    if ( GetSafeAttribs() == nullptr)
       return false ;
 
-  // assegno il nome
+  // assegno l'Info
    return m_pAttribs->SetInfo( sKey, sInfo) ;
 }
 
@@ -696,10 +708,22 @@ GdbObj::GetInfo( const string& sKey, string& sInfo) const
    if ( m_pAttribs == nullptr)
       return false ;
 
-  // restituisco il nome
+  // restituisco l'Info
    return m_pAttribs->GetInfo( sKey, sInfo) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GdbObj::ExistsInfo( const string& sKey) const
+{
+  // se non ci sono attributi
+   if ( m_pAttribs == nullptr)
+      return false ;
+
+  // verifico l'esistenza dell'Info
+   return m_pAttribs->ExistsInfo( sKey) ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GdbObj::RemoveInfo( const string& sKey)
@@ -708,6 +732,6 @@ GdbObj::RemoveInfo( const string& sKey)
    if ( m_pAttribs == nullptr)
       return false ;
 
-  // cancello il nome
+  // cancello l'Info
    return m_pAttribs->RemoveInfo( sKey) ;
 }
diff --git a/GdbObj.h b/GdbObj.h
index 7c6df13..2389d08 100644
--- a/GdbObj.h
+++ b/GdbObj.h
@@ -80,9 +80,11 @@ class GdbObj
       bool GetCalcMaterial( Color& cCol) const ;
       bool SetName( const std::string& sName) ;
       bool GetName( std::string& sName) const ;
+      bool ExistsName( void) const ;
       bool RemoveName( void) ;
       bool SetInfo( const std::string& sKey, const std::string& sInfo) ;
       bool GetInfo( const std::string& sKey, std::string& sInfo) const ;
+      bool ExistsInfo( const std::string& sKey) const ;
       bool RemoveInfo( const std::string& sKey) ;
 
    public :
diff --git a/GeomDB.cpp b/GeomDB.cpp
index dfb8302..ff090cf 100644
--- a/GeomDB.cpp
+++ b/GeomDB.cpp
@@ -183,7 +183,7 @@ GeomDB::LoadOneObj( NgeReader& ngeIn, bool& bEnd)
   // se lettura dati e inserimento nel DB vanno bene
    int nParentId ;
    if ( pGdbObj->Load( nKey, ngeIn, nParentId)  &&
-        AddToGeomDB( pGdbObj, nParentId))
+        InsertInGeomDB( pGdbObj, nParentId, GDB_SON))
       return true ;
   // altrimenti errore
    else {
@@ -306,7 +306,7 @@ GeomDB::GetGdbObj( int nId) const
 
 //----------------------------------------------------------------------------
 bool
-GeomDB::AddToGeomDB( GdbObj* pGObj, int nParentId)
+GeomDB::InsertInGeomDB( GdbObj* pGObj, int nRefId, int nSonBeforeAfter)
 {
   // verifico validità oggetto puntato
    if ( pGObj == nullptr)
@@ -316,13 +316,30 @@ GeomDB::AddToGeomDB( GdbObj* pGObj, int nParentId)
    if ( pGObj->m_nId <= GDB_ID_ROOT  ||  ExistsObj( pGObj->m_nId))
       return false ;
 
-  // cerco il padre
-   GdbGroup* pGroup = GetGdbGroup( nParentId) ;
-   if ( pGroup == nullptr)
+  // cerco il riferimento
+   GdbObj* pGRef = GetGdbObj( nRefId) ;
+   if ( pGRef == nullptr)
       return false ;
-  // inserisco in coda alla lista del padre
-   if ( ! pGObj->AddTail( pGroup))
-       return false ;
+
+  // inserisco prima del riferimento
+   if ( nSonBeforeAfter <= GDB_BEFORE) {
+      if ( ! pGObj->InsertBefore( pGRef))
+          return false ;
+   }
+  // inserisco dopo il riferimento
+   else if ( nSonBeforeAfter >= GDB_AFTER) {
+      if ( ! pGObj->InsertAfter( pGRef))
+          return false ;
+   }
+  // inserisco come figlio, in coda alla lista del padre
+   else {
+      GdbGroup* pGroup = dynamic_cast<GdbGroup*> ( pGRef) ;
+      if ( pGroup == nullptr)
+         return false ;
+     // inserisco in coda alla lista del padre
+      if ( ! pGObj->AddTail( pGroup))
+          return false ;
+   }
 
   // inserisco in mappa Id
    return m_IdManager.AddObj( pGObj->m_nId, pGObj) ;
@@ -332,11 +349,15 @@ GeomDB::AddToGeomDB( GdbObj* pGObj, int nParentId)
 int
 GeomDB::AddGroup( int nId, int nParentId, const Frame3d& frFrame)
 {
-   GdbGroup* pGdbGroup ;
+   return InsertGroup( nId, nParentId, GDB_SON, frFrame) ;
+}
 
-
-  // verifico validità ParentId
-   if ( nParentId < GDB_ID_ROOT)
+//----------------------------------------------------------------------------
+int
+GeomDB::InsertGroup( int nId, int nRefId, int nSonBeforeAfter, const Frame3d& frFrame)
+{
+  // verifico validità apparente RefId
+   if ( nRefId < GDB_ID_ROOT)
       return GDB_ID_NULL ;
   // verifico validità Id
    if ( nId <= GDB_ID_ROOT)
@@ -344,7 +365,7 @@ GeomDB::AddGroup( int nId, int nParentId, const Frame3d& frFrame)
    if ( ExistsObj( nId))
       return GDB_ID_NULL ;
   // alloco gruppo Gdb
-   pGdbGroup = new(nothrow) GdbGroup ;
+   GdbGroup* pGdbGroup = new(nothrow) GdbGroup ;
    if ( pGdbGroup == nullptr)
       return GDB_ID_NULL ;
   // assegno identificativo
@@ -352,7 +373,7 @@ GeomDB::AddGroup( int nId, int nParentId, const Frame3d& frFrame)
   // assegno riferimento
    pGdbGroup->m_gfrFrame.Set( frFrame) ;
   // inserisco nel DB
-   if ( ! AddToGeomDB( pGdbGroup, nParentId)) {
+   if ( ! InsertInGeomDB( pGdbGroup, nRefId, nSonBeforeAfter)) {
       delete pGdbGroup ;
       return GDB_ID_NULL ;
    }
@@ -364,9 +385,13 @@ GeomDB::AddGroup( int nId, int nParentId, const Frame3d& frFrame)
 int
 GeomDB::AddGeoObj( int nId, int nParentId, IGeoObj* pGeoObj)
 {
-   GdbGeo* pGdbGeo ;
-
+   return InsertGeoObj( nId, nParentId, GDB_SON, pGeoObj) ;
+}
 
+//----------------------------------------------------------------------------
+int
+GeomDB::InsertGeoObj( int nId, int nRefId, int nBeforeAfter, IGeoObj* pGeoObj)
+{
   // assegno GeoObj a gestore puntatore con rilascio automatico
    PtrOwner<IGeoObj> pRPGeoObj( pGeoObj) ;
   // verifico validità identificativo
@@ -378,7 +403,7 @@ GeomDB::AddGeoObj( int nId, int nParentId, IGeoObj* pGeoObj)
    if ( ! IsValid( pRPGeoObj)  ||  ! pRPGeoObj->IsValid())
       return GDB_ID_NULL ;
   // alloco oggetto Gdb
-   pGdbGeo = new(nothrow) GdbGeo ;
+   GdbGeo* pGdbGeo = new(nothrow) GdbGeo ;
    if ( pGdbGeo == nullptr)
       return GDB_ID_NULL ;
   // assegno identificativo
@@ -386,7 +411,7 @@ GeomDB::AddGeoObj( int nId, int nParentId, IGeoObj* pGeoObj)
   // assegno dati
    pGdbGeo->m_pGeoObj = Release( pRPGeoObj) ;
   // inserisco nel DB
-   if ( ! AddToGeomDB( pGdbGeo, nParentId)) {
+   if ( ! InsertInGeomDB( pGdbGeo, nRefId, nBeforeAfter)) {
       delete pGdbGeo ;
       return GDB_ID_NULL ;
    }
@@ -394,14 +419,78 @@ GeomDB::AddGeoObj( int nId, int nParentId, IGeoObj* pGeoObj)
    return nId ;
 }
 
+//----------------------------------------------------------------------------
+int
+GeomDB::GetFirstInGroup( int nIdGroup) const
+{
+  // recupero il gruppo
+   const GdbGroup* pGdbGroup = GetGdbGroup( nIdGroup) ;
+   if ( pGdbGroup == nullptr)
+      return GDB_ID_NULL ;
+
+  // recupero il primo oggetto del gruppo
+   const GdbObj* pGdbO = pGdbGroup->GetFirstObj() ;
+   if ( pGdbO == nullptr)
+      return GDB_ID_NULL ;
+
+   return ( pGdbO->m_nId) ;
+}
+
+//----------------------------------------------------------------------------
+int
+GeomDB::GetNext( int nId) const
+{
+  // recupero l'oggetto
+   const GdbObj* pGdbObj = GetGdbObj( nId) ;
+   if ( pGdbObj == nullptr)
+      return GDB_ID_NULL ;
+  // recupero il successivo
+   const GdbObj* pGdbNext = pGdbObj->GetNext() ;
+   if ( pGdbNext == nullptr)
+      return GDB_ID_NULL ;
+
+   return ( pGdbNext->m_nId) ;
+}
+
+//----------------------------------------------------------------------------
+int
+GeomDB::GetLastInGroup( int nIdGroup) const
+{
+  // recupero il gruppo
+   const GdbGroup* pGdbGroup = GetGdbGroup( nIdGroup) ;
+   if ( pGdbGroup == nullptr)
+      return GDB_ID_NULL ;
+
+  // recupero l'ultimo oggetto del gruppo
+   const GdbObj* pGdbO = pGdbGroup->GetLastObj() ;
+   if ( pGdbO == nullptr)
+      return GDB_ID_NULL ;
+
+   return ( pGdbO->m_nId) ;
+}
+
+//----------------------------------------------------------------------------
+int
+GeomDB::GetPrev( int nId) const
+{
+  // recupero l'oggetto
+   const GdbObj* pGdbObj = GetGdbObj( nId) ;
+   if ( pGdbObj == nullptr)
+      return GDB_ID_NULL ;
+  // recupero il precedente
+   const GdbObj* pGdbPrev = pGdbObj->GetPrev() ;
+   if ( pGdbPrev == nullptr)
+      return GDB_ID_NULL ;
+
+   return ( pGdbPrev->m_nId) ;
+}
+
 //----------------------------------------------------------------------------
 int
 GeomDB::GetGdbType( int nId) const
 {
-   const GdbObj* pGdbObj ;
-
-
   // recupero l'oggetto
+   const GdbObj* pGdbObj ;
    if ( ( pGdbObj = GetGdbObj( nId)) == nullptr)
       return GDB_TY_NONE ;
 
@@ -568,7 +657,7 @@ GeomDB::Copy( int nIdSou, int nIdDest, int nParentIdDest)
       return GDB_ID_NULL ;
 
   // inserisco nel DB
-   if ( ! AddToGeomDB( pGdODest, nParentIdDest)) {
+   if ( ! InsertInGeomDB( pGdODest, nParentIdDest, GDB_SON)) {
       delete pGdODest ;
       return GDB_ID_NULL ;
    }
@@ -613,7 +702,7 @@ GeomDB::CopyGlob( int nIdSou, int nIdDest, int nParentIdDest)
    } 
 
   // inserisco nel DB
-   if ( ! AddToGeomDB( pGdODest, nParentIdDest)) {
+   if ( ! InsertInGeomDB( pGdODest, nParentIdDest, GDB_SON)) {
       delete pGdODest ;
       return GDB_ID_NULL ;
    }
@@ -1670,6 +1759,19 @@ GeomDB::GetName( int nId, string& sName) const
    return pGdbObj->GetName( sName) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GeomDB::ExistsName( int nId) const
+{
+  // recupero l'oggetto
+   const GdbObj* pGdbObj ;
+   if ( ( pGdbObj = GetGdbObj( nId)) == nullptr)
+      return false ;
+
+  // recupero il nome
+   return pGdbObj->ExistsName() ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GeomDB::RemoveName( int nId)
@@ -1709,6 +1811,19 @@ GeomDB::GetInfo( int nId, const string& sKey, string& sInfo) const
    return pGdbObj->GetInfo( sKey, sInfo) ;
 }
 
+//----------------------------------------------------------------------------
+bool
+GeomDB::ExistsInfo( int nId, const string& sKey) const
+{
+  // recupero l'oggetto
+   const GdbObj* pGdbObj ;
+   if ( ( pGdbObj = GetGdbObj( nId)) == nullptr)
+      return false ;
+
+  // verifico l'esistenza dell'Info
+   return pGdbObj->ExistsInfo( sKey) ;
+}
+
 //----------------------------------------------------------------------------
 bool
 GeomDB::RemoveInfo( int nId, const string& sKey)
diff --git a/GeomDB.h b/GeomDB.h
index 83ee371..0059bb5 100644
--- a/GeomDB.h
+++ b/GeomDB.h
@@ -35,7 +35,13 @@ class GeomDB : public IGeomDB
       virtual bool Save( const std::string& sFileOut, bool bBinary = true) const ;
       virtual bool ExistsObj( int nId) const ;
       virtual int  AddGroup( int nId, int nParentId, const Frame3d& frFrame) ;
+      virtual int  InsertGroup( int nId, int nRefId, int nSonBeforeAfter, const Frame3d& frFrame) ;
       virtual int  AddGeoObj( int nId, int nParentId, IGeoObj* pGeoObj) ;
+      virtual int  InsertGeoObj( int nId, int nRefId, int nSonBeforeAfter, IGeoObj* pGeoObj) ;
+      virtual int  GetFirstInGroup( int nIdGroup) const ;
+      virtual int  GetNext( int nId) const ;
+      virtual int  GetLastInGroup( int nIdGroup) const ;
+      virtual int  GetPrev( int nId) const ;
       virtual int  GetGdbType( int nId) const ;
       virtual IGeoObj* GetGeoObj( int nId) ;
       virtual IGeoFrame3d* GetGeoFrame( int nId) ;
@@ -117,9 +123,11 @@ class GeomDB : public IGeomDB
       virtual bool GetCalcMaterial( int nId, Color& cCol) const ;
       virtual bool SetName( int nId, const std::string& sName) ;
       virtual bool GetName( int nId, std::string& sName) const ;
+      virtual bool ExistsName( int nId) const ;
       virtual bool RemoveName( int nId) ;
       virtual bool SetInfo( int nId, const std::string& sKey, const std::string& sInfo) ;
       virtual bool GetInfo( int nId, const std::string& sKey, std::string& sInfo) const ;
+      virtual bool ExistsInfo( int nId, const std::string& sKey) const ;
       virtual bool RemoveInfo( int nId, const std::string& sKey) ;
      // material library
       virtual int  AddMaterial( const std::string& sName, const Material& matM) ;
@@ -147,7 +155,7 @@ class GeomDB : public IGeomDB
                  { return dynamic_cast<GdbGroup*>( GetGdbObj( nId)) ; }
       const GdbGroup* GetGdbGroup( int nId) const
                  { return dynamic_cast<const GdbGroup*>( GetGdbObj( nId)) ; }
-      bool AddToGeomDB( GdbObj* pGObj, int nParentId) ;
+      bool InsertInGeomDB( GdbObj* pGObj, int nRefId, int nSonBeforeAfter) ;
       bool Relocate( int nId, int nNewParentId, bool bGlob) ;
       bool Erase( GdbObj* pGObj) ;
       bool LoadHeader( NgeReader& ngeIn) ;
diff --git a/PointGrid3d.cpp b/PointGrid3d.cpp
index 2802628..b2d3742 100644
--- a/PointGrid3d.cpp
+++ b/PointGrid3d.cpp
@@ -22,7 +22,8 @@ using namespace std ;
 bool
 PointGrid3d::Init( int nBuckets, double dCellDim)
 {
-   m_dCellDim = dCellDim ;
+   m_dCellDim = max( dCellDim, EPS_SMALL) ;
+   m_dInvCellDim = 1 / m_dCellDim ;
    try { m_MMap.rehash( nBuckets) ;}
    catch(...) { return false ;}
    return true ;
@@ -101,7 +102,7 @@ PointGrid3d::Find( const Point3d& ptTest, double dTol, int& nId)
 int
 PointGrid3d::Get1dCellNbr( double dCoord)
 {
-   return static_cast<int>( floor( dCoord / m_dCellDim)) ;
+   return static_cast<int>( floor( dCoord * m_dInvCellDim)) ;
 }
 
 //----------------------------------------------------------------------------
diff --git a/SurfTriMesh.cpp b/SurfTriMesh.cpp
index 9822b2b..ee02109 100644
--- a/SurfTriMesh.cpp
+++ b/SurfTriMesh.cpp
@@ -112,7 +112,7 @@ SurfTriMesh::SetVertex( int nInd, const StmVert& vV)
 int
 SurfTriMesh::AddTriangle( const int nIdVert[3])
 {
-  // verifico che i tre indici diano diversi
+  // verifico che i tre indici siano diversi
    if ( nIdVert[0] == nIdVert[1]  ||
         nIdVert[1] == nIdVert[2]  ||
         nIdVert[2] == nIdVert[0])