diff --git a/EXE_GdbCreateSurf.cpp b/EXE_GdbCreateSurf.cpp
index 3af6883..24c7cf2 100644
--- a/EXE_GdbCreateSurf.cpp
+++ b/EXE_GdbCreateSurf.cpp
@@ -2668,6 +2668,88 @@ ExeCreateSurfBzRuled( int nParentId, int nCrvId1, int nCrvId2, int nRuledType, b
    return nNewId ;
 }
 
+//-------------------------------------------------------------------------------
+int
+ExeCreateSurfBzRuledGuided( int nParentId, int nCrvId1, int nCrvId2, int nLayGuides, bool bCapEnds, double dLinTol)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, GDB_ID_NULL)
+   nParentId = AdjustId( nParentId) ;
+   bool bOk = true ;
+  // recupero il riferimento locale
+   Frame3d frLoc ;
+   bOk = bOk && pGeomDB->GetGroupGlobFrame( nParentId, frLoc) ;
+  // recupero le curve in locale
+   CurveLocal CrvLoc1( pGeomDB, nCrvId1, frLoc) ;
+   bOk = bOk && ( CrvLoc1.Get() != nullptr) ;
+   CurveLocal CrvLoc2( pGeomDB, nCrvId2, frLoc) ;
+   bOk = bOk && ( CrvLoc2.Get() != nullptr) ;
+   ICURVEPOVECTOR vCrv ;
+   int nId = pGeomDB->GetFirstInGroup( nLayGuides) ;
+   while( nId != GDB_ID_NULL  &&  bOk) {
+      CurveLocal CrvLocGuide( pGeomDB, nId, frLoc) ;
+      bOk = bOk && ( CrvLocGuide.Get() != nullptr) ;
+      vCrv.emplace_back( CrvLocGuide.Get()->Clone()) ;
+      nId = pGeomDB->GetNext( nId) ;
+   }
+
+  // calcolo la superficie
+   PtrOwner<ISurfBezier> pSbz( bOk ? GetSurfBezierRuledGuided( CrvLoc1, CrvLoc2, vCrv, dLinTol) : nullptr) ;
+   bOk = bOk && ! IsNull( pSbz) ;
+  // verifiche per orientamento se con tappi
+   bool bWithCaps = false ;
+   bool bStdOrient = true ;
+   Plane3d plPlane1, plPlane2 ;
+   double dArea1, dArea2 ;
+   if ( bOk  &&  bCapEnds  &&
+        CrvLoc1->IsClosed()  &&  CrvLoc2->IsClosed()  &&  CrvLoc1->GetArea( plPlane1, dArea1)  &&  CrvLoc2->GetArea( plPlane2, dArea2)) {
+      bWithCaps = true ;
+      Point3d ptStart1 ; CrvLoc1->GetStartPoint( ptStart1) ;
+      Point3d ptStart2 ; CrvLoc2->GetStartPoint( ptStart2) ;
+      Vector3d vtRuling = ptStart2 - ptStart1 ;
+      bStdOrient = ( vtRuling * plPlane1.GetVersN() > 0) ;
+      if ( ! bStdOrient)
+         pSbz->Invert() ;
+   }
+   
+  // inserisco la superficie nel DB
+   int nNewId = ( bOk ? pGeomDB->AddGeoObj( GDB_ID_NULL, nParentId, Release( pSbz)) : GDB_ID_NULL) ;
+
+  // se richiesto inserisco anche il cap
+   if ( bOk  &&  bWithCaps) {
+     // costruisco la superficie dalla curva 1
+      PtrOwner<ISurfBezier> pSbzFlat1( CreateSurfBezier()) ;
+      double dAngTolDeg = 5 ;
+      PolyLine pl1 ; CrvLoc1->ApproxWithLines(dLinTol, dAngTolDeg, ICurve::APL_STD, pl1) ;
+      pSbzFlat1->CreateByFlatContour( pl1) ;
+      if ( bStdOrient)
+         pSbzFlat1->Invert() ;
+     // inserisco la superficie nel DB
+      bOk = bOk &&  pGeomDB->AddGeoObj( GDB_ID_NULL, nParentId, Release( pSbzFlat1)) ;
+     // costruisco la superficie dalla curva 2
+      PtrOwner<ISurfBezier> pSbzFlat2( CreateSurfBezier()) ;
+      PolyLine pl2 ; CrvLoc2->ApproxWithLines(dLinTol, dAngTolDeg, ICurve::APL_STD, pl2) ;
+      pSbzFlat2->CreateByFlatContour( pl2) ;
+      if ( ! bStdOrient)
+         pSbzFlat2->Invert() ;
+     // inserisco la superficie nel DB
+      bOk = bOk  &&  pGeomDB->AddGeoObj( GDB_ID_NULL, nParentId, Release( pSbzFlat2)) ;
+   }
+   ExeSetModified() ;
+  // se richiesto, salvo il comando Lua equivalente
+   if ( IsCmdLog()) {
+      string sLua = "EgtSurfBzRuledGuided(" + IdToString( nParentId) + "," +
+                                              ToString( nCrvId1) + "," +
+                                              ToString( nCrvId2) + "," +
+                                              ( bCapEnds ? "true" : "false") + "," +  
+                                              ToString( dLinTol) + ")" +
+                                             " -- Id=" + ToString( nNewId) ;
+      LOG_INFO( GetCmdLogger(), sLua.c_str()) ;
+   }
+   // restituisco l'identificativo della nuova entità
+   return nNewId ;
+}
+
 //-------------------------------------------------------------------------------
 int
 ExeCreateSurfBzSkinned( int nParentId, const INTVECTOR& vCrvIds, bool bCapEnds, double dLinTol)
diff --git a/LUA_GdbCreateSurf.cpp b/LUA_GdbCreateSurf.cpp
index a96b2c0..38e6fcf 100644
--- a/LUA_GdbCreateSurf.cpp
+++ b/LUA_GdbCreateSurf.cpp
@@ -1349,7 +1349,7 @@ LuaCreateSurfBzRuled( lua_State* L)
    double dLinTol = LIN_TOL_SRF ;
    LuaGetParam( L, nPar, dLinTol) ;
    LuaClearStack( L) ;
-   // creo STM riempiendo un contorno piano
+   // creo una surf bezier come rigata tra le due curve passate
    int nId = ExeCreateSurfBzRuled( nParentId, nCrvId1, nCrvId2, nRuledType, bCapEnds, dLinTol) ;
    // restituisco il risultato
    if ( nId != GDB_ID_NULL)
@@ -1359,6 +1359,36 @@ LuaCreateSurfBzRuled( lua_State* L)
    return 1 ;
 }
 
+//-------------------------------------------------------------------------------
+static int
+LuaCreateSurfBzRuledGuided( lua_State* L)
+{
+   // 4 o 5 o 6 parametri : ParentId, CrvId1, CrvId2 nLayGuides [, bCapEnds] [, dTol]
+   int nParentId ;
+   LuaCheckParam( L, 1, nParentId)
+   int nCrvId1 ;
+   LuaCheckParam( L, 2, nCrvId1)
+   int nCrvId2 ;
+   LuaCheckParam( L, 3, nCrvId2)
+   int nLayGuides ;
+   LuaCheckParam( L, 4, nLayGuides)
+   bool bCapEnds = false ;
+   int nPar = 5 ;
+   if ( LuaGetParam( L, nPar, bCapEnds))
+      ++ nPar ;
+   double dLinTol = LIN_TOL_SRF ;
+   LuaGetParam( L, nPar, dLinTol) ;
+   LuaClearStack( L) ;
+   // creo una surf bezier come rigata tra le due curve passate, usando le isocurve nel layer nLayIso
+   int nId = ExeCreateSurfBzRuledGuided( nParentId, nCrvId1, nCrvId2, nLayGuides, bCapEnds, dLinTol) ;
+   // restituisco il risultato
+   if ( nId != GDB_ID_NULL)
+      LuaSetParam( L, nId) ;
+   else
+      LuaSetParam( L) ;
+   return 1 ;
+}
+
 //-------------------------------------------------------------------------------
 static int
 LuaCreateSurfBzSkinned( lua_State* L)
@@ -1472,6 +1502,7 @@ LuaInstallGdbCreateSurf( LuaMgr& luaMgr)
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzByRevolve", LuaCreateSurfBzByRevolve) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzByPointCurve", LuaCreateSurfBzByPointCurve) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzRuled", LuaCreateSurfBzRuled) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzRuledGuided", LuaCreateSurfBzRuledGuided) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzSkinned", LuaCreateSurfBzSkinned) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfBzSwept", LuaCreateSurfBzSwept) ;
    return bOk ;