diff --git a/EgtGeomKernel.rc b/EgtGeomKernel.rc
index 04141b8..60d7285 100644
Binary files a/EgtGeomKernel.rc and b/EgtGeomKernel.rc differ
diff --git a/GeomDB.cpp b/GeomDB.cpp
index 964cf4b..ffe03d7 100644
--- a/GeomDB.cpp
+++ b/GeomDB.cpp
@@ -613,7 +613,7 @@ GeomDB::GetGdbObj( int nId) const
   // radice
    else if ( nId == GDB_ID_ROOT)
       return &m_GrpRadix ;
-  // un nodo qualubque
+  // un nodo qualunque
    else
       return m_IdManager.FindObj( nId) ;
 }
@@ -660,7 +660,7 @@ GeomDB::InsertInGeomDB( GdbObj* pGObj, int nRefId, int nSonBeforeAfter, bool bLo
           return false ;
    }
   // inserisco come figlio, in testa alla lista del padre
-   else if ( nSonBeforeAfter == GDB_FIRST_SON){
+   else if ( nSonBeforeAfter == GDB_FIRST_SON) {
       GdbGroup* pGroup = ::GetGdbGroup( pGRef) ;
       if ( pGroup == nullptr)
          return false ;
diff --git a/GeomDB.h b/GeomDB.h
index 6e0f18a..ef16fb8 100644
--- a/GeomDB.h
+++ b/GeomDB.h
@@ -31,6 +31,8 @@ class GeomDB : public IGeomDB
    friend class GdbGeo ;
    friend int CopyGeoObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId, int nSonBeforeAfter, bool bGlob) ;
    friend int CopyGroupObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId, int nSonBeforeAfter, bool bGlob) ;
+   friend int DuplicateGeoObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId) ;
+   friend int DuplicateGroupObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId, bool bSkipTemp) ;
 
    public :
       ~GeomDB( void) override ;
diff --git a/MultiGeomDB.cpp b/MultiGeomDB.cpp
index b81b1cd..a5c43d8 100644
--- a/MultiGeomDB.cpp
+++ b/MultiGeomDB.cpp
@@ -23,9 +23,6 @@ using namespace std ;
 static int
 CopyGeoObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId, int nSonBeforeAfter, bool bGlob)
 {
-  // verifico i puntatori ai GeomDB
-   if ( pSouGDB == nullptr  ||  pDstGDB == nullptr)
-      return GDB_ID_NULL ;
   // recupero l'oggetto da copiare dal GeomDB sorgente
    PtrOwner<IGeoObj> pGObj( pSouGDB->GetGeoObj( nSouId)->Clone()) ;
    if ( IsNull( pGObj))
@@ -109,7 +106,7 @@ CopyGroupObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, i
          nSonNewId = CopyGeoObj( pSouGDB, nSonSouId, pDstGDB, GDB_ID_NULL, nNewId, GDB_LAST_SON, false) ;
      // se altrimenti è un gruppo
       else if ( nSonSouType == GDB_TY_GROUP)
-         nSonNewId = CopyGroupObj(  pSouGDB, nSonSouId, pDstGDB, GDB_ID_NULL, nNewId, GDB_LAST_SON, false) ;
+         nSonNewId = CopyGroupObj( pSouGDB, nSonSouId, pDstGDB, GDB_ID_NULL, nNewId, GDB_LAST_SON, false) ;
      // se copia non riuscita, esco con errore
       if ( nSonNewId == GDB_ID_NULL)
          return GDB_ID_NULL ;
@@ -129,6 +126,9 @@ Copy( IGeomDB* pSouGeomDB, int nSouId, IGeomDB* pDestGeomDB, int nDestId, int nR
    GeomDB* pDstGDB = static_cast<GeomDB*>( pDestGeomDB) ;
    if ( pSouGDB == nullptr  ||  pDstGDB == nullptr)
       return GDB_ID_NULL ;
+  // il sorgente non può essere il gruppo radice
+   if ( nSouId == GDB_ID_ROOT)
+      return GDB_ID_NULL ;
   // nuovo identificativo oggetto destinazione
    int nNewId = GDB_ID_NULL ;
   // recupero il tipo di oggetto sorgente
@@ -158,3 +158,101 @@ CopyGlob( IGeomDB* pSouGeomDB, int nSouId, IGeomDB* pDestGeomDB, int nDestId, in
 {
    return Copy( pSouGeomDB, nSouId, pDestGeomDB, nDestId, nRefId, nSonBeforeAfter, true) ;
 }
+
+//----------------------------------------------------------------------------
+static int
+DuplicateGeoObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId)
+{
+  // recupero l'oggetto da copiare dal GeomDB sorgente
+   PtrOwner<IGeoObj> pGObj( pSouGDB->GetGeoObj( nSouId)->Clone()) ;
+   if ( IsNull( pGObj))
+      return GDB_ID_NULL ;
+  // lo inserisco nel GeomDB destinazione
+   int nNewId = pDstGDB->InsertGeoObj( nDestId, nRefId, GDB_LAST_SON, Release( pGObj)) ;
+   if ( nNewId != nDestId) {
+      pDstGDB->Erase( nNewId) ;
+      return GDB_ID_NULL ;
+   }
+  // copio le caratteristiche non geometriche
+   const GdbObj* pSouGdbObj = pSouGDB->GetGdbObj( nSouId) ;
+   GdbObj* pDstGdbObj = pDstGDB->GetGdbObj( nNewId) ;
+   if ( pSouGDB == nullptr  ||  pDstGdbObj == nullptr  ||
+        ! pDstGdbObj->CopyAttribsFrom( pSouGdbObj)  ||
+        ! pDstGdbObj->CopyTextureDataFrom( pSouGdbObj)  ||
+        ! pDstGdbObj->CopyStippleDataFrom( pSouGdbObj)  ||
+        ! pDstGdbObj->CopyUserObjFrom( pSouGdbObj)) {
+      pDstGDB->Erase( nNewId) ;
+      return GDB_ID_NULL ;
+   }
+
+   return nNewId ;
+}
+
+//----------------------------------------------------------------------------
+static int
+DuplicateGroupObj( const GeomDB* pSouGDB, int nSouId, GeomDB* pDstGDB, int nDestId, int nRefId, bool bSkipTemp)
+{
+   int nNewId = GDB_ID_ROOT ;
+   if ( nSouId != GDB_ID_ROOT) {
+     // recupero il riferimento del gruppo
+      Frame3d frFrame = *( pSouGDB->GetGroupFrame( nSouId)) ;
+     // inserisco un nuovo gruppo nel GeomDB destinazione
+      nNewId = pDstGDB->InsertGroup( nDestId, nRefId, GDB_LAST_SON, frFrame) ;
+      if ( nNewId != nSouId) {
+         pDstGDB->Erase( nNewId) ;
+         return GDB_ID_NULL ;
+      }
+     // copio le caratteristiche non geometriche
+      const GdbObj* pSouGdbObj = pSouGDB->GetGdbObj( nSouId) ;
+      GdbObj* pDstGdbObj = pDstGDB->GetGdbObj( nNewId) ;
+      if ( pSouGDB == nullptr  ||  pDstGdbObj == nullptr  ||
+           ! pDstGdbObj->CopyAttribsFrom( pSouGdbObj)  ||
+           ! pDstGdbObj->CopyTextureDataFrom( pSouGdbObj)  ||
+           ! pDstGdbObj->CopyStippleDataFrom( pSouGdbObj)  ||
+           ! pDstGdbObj->CopyUserObjFrom( pSouGdbObj)) {
+         pDstGDB->Erase( nNewId) ;
+         return GDB_ID_NULL ;
+      }
+   }
+  // copio gli eventuali figli
+   int nSonSouId = pSouGDB->GetFirstInGroup( nSouId) ;
+   while ( nSonSouId != GDB_ID_NULL) {
+     // verifico se non richiesto di saltare i temporanei oppure non lo è
+      int nLevel ;
+      if ( ! bSkipTemp  ||  ! pSouGDB->GetLevel( nSonSouId, nLevel)  ||  nLevel != GDB_LV_TEMP) {
+        // nuovo identificativo oggetto destinazione
+         int nSonNewId = GDB_ID_NULL ;
+        // recupero il tipo di oggetto sorgente
+         int nSonSouType = pSouGDB->GetGdbType( nSonSouId) ;
+        // se l'oggetto da copiare è geometrico
+         if ( nSonSouType == GDB_TY_GEO)
+            nSonNewId = DuplicateGeoObj( pSouGDB, nSonSouId, pDstGDB, nSonSouId, nNewId) ;
+        // se altrimenti è un gruppo
+         else if ( nSonSouType == GDB_TY_GROUP)
+            nSonNewId = DuplicateGroupObj( pSouGDB, nSonSouId, pDstGDB, nSonSouId, nNewId, bSkipTemp) ;
+        // se copia non riuscita, esco con errore
+         if ( nSonNewId != nSonSouId)
+            return GDB_ID_NULL ;
+      }
+     // passo al figlio successivo
+      nSonSouId = pSouGDB->GetNext( nSonSouId) ;
+   }
+
+   return nNewId ;
+}
+
+//----------------------------------------------------------------------------
+bool
+DuplicateGeomDB( IGeomDB* pSouGeomDB, IGeomDB* pDestGeomDB, bool bSkipTemp)
+{
+  // adatto e verifico i GeomDB
+   const GeomDB* pSouGDB = static_cast<GeomDB*>( pSouGeomDB) ;
+   GeomDB* pDstGDB = static_cast<GeomDB*>( pDestGeomDB) ;
+   if ( pSouGDB == nullptr  ||  pDstGDB == nullptr)
+      return false ;
+  // verifico che la destinazione sia vuota
+   if ( pDstGDB->GetFirstInGroup( GDB_ID_ROOT) != GDB_ID_NULL)
+      return false ;
+  // eseguo la copia di tutto (se richiesto salto gli oggetti temporanei)
+   return ( DuplicateGroupObj( pSouGDB, GDB_ID_ROOT, pDstGDB, GDB_ID_ROOT, GDB_ID_ROOT, bSkipTemp) != GDB_ID_NULL) ;
+}