diff --git a/SurfFlatRegionOffset.cpp b/SurfFlatRegionOffset.cpp
index 4d549a3..2bc7780 100644
--- a/SurfFlatRegionOffset.cpp
+++ b/SurfFlatRegionOffset.cpp
@@ -16,6 +16,7 @@
 #include "GeoConst.h"
 #include "CurveComposite.h"
 #include "SurfFlatRegion.h"
+#include "AdjustLoops.h"
 #include "Voronoi.h"
 #include "/EgtDev/Include/EGkOffsetCurve.h"
 #include "/EgtDev/Include/EGkSfrCreate.h"
@@ -146,51 +147,23 @@ SurfFlatRegion::CreateOffsetSurf( double dDist, int nType) const
       if ( ! m_pVoronoiObj->CalcOffset( vOffs, dDist, nType))
          return nullptr ;
 
+     // costruisco la superficie
       if ( vOffs.size() > 0) {
-         BOOLVECTOR vbAddOrSub( vOffs.size(), true) ;
-         int nFirstId = -1 ;
-         for ( int i = 0 ; i < ( int)vOffs.size() ; i ++) {
-           // porto nel frame della flat region
+         PCRV_DEQUE vLoops ;
+         for ( int i = 0 ; i < int( vOffs.size()) ; i ++) {
             vOffs[i]->ToLoc( m_frF) ;
-           // calcolo orientamento della curva
-            double dAreaXY ;
-            if ( ! vOffs[i]->GetAreaXY( dAreaXY))
-               return nullptr ;
-            vbAddOrSub[i] = ( dAreaXY > SQ_EPS_SMALL) ;
-           // verifico se è il primo loop esterno
-            if ( nFirstId == -1  &&  vbAddOrSub[i])
-               nFirstId = i ;
-         }
-
-        // inizializzo la superficie
-         if ( nFirstId != -1  &&  ! pSfr->AddExtLoop( Release( vOffs[nFirstId])))
-            return nullptr ;
-         if ( pSfr->IsValid()) {
-
-            for ( int i = 0 ; i < ( int)vOffs.size() ; i ++) {
-              // verifico non sia il primo loop esterno
-               if ( i == nFirstId)
-                  continue ;
-              // costruisco la superficie associata
-               PtrOwner<SurfFlatRegion> pSrfCrv( CreateBasicSurfFlatRegion()) ;
-               if ( IsNull( pSrfCrv)  ||  ! pSrfCrv->AddExtLoop( Release( vOffs[i])))
-                  return nullptr ;
-               if ( ! pSrfCrv->IsValid())
-                  continue ;
-
-              // aggiungo o sottraggo
-               if ( vbAddOrSub[i]) {
-                  if ( ! pSfr->Add( *pSrfCrv))
-                     return nullptr ;
-               }
-               else {
-                  pSrfCrv->Invert() ;
-                  if ( ! pSfr->Subtract( *pSrfCrv))
-                     return nullptr ;
-               }
-            }
-
+           // rimuovo eventuali sovrapposizioni
+            ICURVEPLIST CrvLst ;
+            AdjustLoops( Release( vOffs[i]), CrvLst, true) ;
+            for ( auto pCrv : CrvLst)
+               vLoops.emplace_back( pCrv) ;
          }
+     
+         pSfr.Set( MyNewSurfFromLoops( vLoops)) ;
+         if ( IsNull( pSfr)) {
+            MyTestAndDelete( vLoops) ;
+            return nullptr ; 
+         }                
       }
    }
 
diff --git a/Voronoi.cpp b/Voronoi.cpp
index 60d02bc..400b6d3 100644
--- a/Voronoi.cpp
+++ b/Voronoi.cpp
@@ -818,12 +818,29 @@ Voronoi::VerifyCurvesValidityForOffset()
 
      // se curva con orientamento principale verifico sia esterna a tutte le altre curve con orientamento principale 
       if ( vArea[i] * dRefArea > EPS_SMALL) {
-         for ( int j = i + 1 ; j < ( int)vArea.size() ; j++) {
-            if ( vArea[i] * vArea[j] > EPS_SMALL) {
+         for ( int j = 0 ; j < ( int)vArea.size() ; j++) {
+            if ( j != i  &&  vArea[i] * vArea[j] > EPS_SMALL) {
                IntersCurveCurve ccInt( *m_vpCrvs[i], *m_vpCrvs[j]) ;
                int nRes = ccInt.GetRegionCurveClassification() ;
-               if ( ( bRefCCW  &&  nRes != CCREGC_OUT)  ||  ( ! bRefCCW  &&  nRes != CCREGC_IN1))
+               if ( nRes == CCREGC_NULL  ||  nRes == CCREGC_SAME  ||  nRes == CCREGC_INTERS)
                   return false ;
+               if ( ( bRefCCW  &&  nRes == CCREGC_IN1)  ||  ( ! bRefCCW  &&  nRes == CCREGC_IN2)) {
+                  // se è interna ad una curva con orientamento principale, verifico sia esterna ad almeno una curva con orientamento
+                  // diverso dal principale
+                   bool bFound = false ;
+                   for ( int k = 0 ; k < ( int)vArea.size() ; k++) {
+                      if ( k != i  &&  vArea[i] * vArea[k] < EPS_SMALL) {
+                         IntersCurveCurve ccInt( *m_vpCrvs[i], *m_vpCrvs[k]) ;
+                         int nRes = ccInt.GetRegionCurveClassification() ;
+                         if ( ( bRefCCW  &&  nRes ==  CCREGC_OUT)  ||  ( ! bRefCCW  &&  nRes == CCREGC_IN1)) {
+                            bFound = true ;
+                            break ;
+                         }                            
+                      }                   
+                   }
+                   if ( ! bFound)
+                      return false ;               
+               }
             }            
          }     
       }