diff --git a/SurfTriMeshBooleans.cpp b/SurfTriMeshBooleans.cpp
index 762b38d..b918274 100644
--- a/SurfTriMeshBooleans.cpp
+++ b/SurfTriMeshBooleans.cpp
@@ -3662,21 +3662,24 @@ SurfTriMesh::SplitFacet( const INTERSCHAINMAP& IntersLineMap, PieceMap& NewFacet
          }
       }
       // Assegno i loop chiusi interni alle rispettive parti di faccia.
-      // Ciclo sui pezzi di facet.
-      int nPieceNum = int( vNewPieces.size()) ;
-      for ( int nPieceN = 0 ; nPieceN < nPieceNum ; ++ nPieceN) {
-         // Ciclo sui loop interni
-         for ( int nInnL = 0 ; nInnL < int( cvClosedChain.size()) ; ++ nInnL) {
-            // Trasformo il loop interno in PolyLine.
-            PolyLine CurInnerLoop ;
-            CurInnerLoop.AddUPoint( 0., cvClosedChain[nInnL][0].ptSt) ;
-            for ( int nSeg = 0 ; nSeg < int( cvClosedChain[nInnL].size()) ; ++ nSeg) {
-               CurInnerLoop.AddUPoint( 0., cvClosedChain[nInnL][nSeg].ptEn) ;
-            }
-            Plane3d plPlane ;
-            double dArea ;
-            if ( ! CurInnerLoop.IsClosedAndFlat( plPlane, dArea)  ||  dArea < EPS_SMALL)
-               continue ;
+      // Ciclo sui loop interni
+      for ( int nInnL = 0 ; nInnL < int( cvClosedChain.size()) ; ++ nInnL) {
+         // Trasformo il loop interno in PolyLine.
+         PolyLine CurInnerLoop ;
+         CurInnerLoop.AddUPoint( 0., cvClosedChain[nInnL][0].ptSt) ;
+         for ( int nSeg = 0 ; nSeg < int( cvClosedChain[nInnL].size()) ; ++ nSeg) {
+            CurInnerLoop.AddUPoint( 0., cvClosedChain[nInnL][nSeg].ptEn) ;
+         }
+         Plane3d plPlane ;
+         double dArea ;
+         if ( ! CurInnerLoop.IsClosedAndFlat( plPlane, dArea)  ||  dArea < EPS_SMALL)
+            continue ;
+         int nIncluderPiece = - 1 ;
+         double dIncluderPieceArea = DBL_MAX ;
+         bool bNewPieceOut = false ;
+         // Ciclo sui pezzi di facet.
+         int nPieceNum = int( vNewPieces.size()) ;
+         for ( int nPieceN = 0 ; nPieceN < nPieceNum ; ++ nPieceN) {  
             // Ciclo sui punti del loop interno.
             PNTULIST& LoopList = CurInnerLoop.GetUPointList() ;
             for ( auto itInn = LoopList.begin() ; itInn != LoopList.end() ; ++ itInn) {
@@ -3688,71 +3691,77 @@ SurfTriMesh::SplitFacet( const INTERSCHAINMAP& IntersLineMap, PieceMap& NewFacet
                   ptInnNextP = itInnNext->first ;
                if ( IsPointInsidePolyLine( ptInnP, vNewPieces[nPieceN].vPieceLoop[0])  ||  ( itInnNext != LoopList.end()  &&
                     IsPointInsidePolyLine( 0.5 * ( ptInnP + ptInnNextP), vNewPieces[nPieceN].vPieceLoop[0]))) {
-                  Polygon3d AuxPolygon ;
-                  AuxPolygon.FromPolyLine( CurInnerLoop) ;
-                  Vector3d vtInnLoopNorm =  AuxPolygon.GetVersN() ;
-                  if ( vtFacetNorm * vtInnLoopNorm < 0.) {
-                     // Aggiungo loop al pezzo.
-                     vNewPieces[nPieceN].nPiecePart = 1 ;
-                     vNewPieces[nPieceN].vPieceLoop.emplace_back( CurInnerLoop) ;
-                     // Aggiungo nuovo pezzo.
-                     vNewPieces.emplace_back() ;
-                     vNewPieces.back().vPieceLoop.emplace_back( CurInnerLoop) ;
-                     vNewPieces.back().vPieceLoop.back().Invert() ;
-                     vNewPieces.back().nPiecePart = - 1 ;
-                     // Cerco loop interni a quello appena aggiunto
-                     INTVECTOR vSecondLevel ;
-                     for ( int nSI = 1 ; nSI < int( vNewPieces[nPieceN].vPieceLoop.size()) ; ++ nSI) {
-                        PNTULIST& SecLevLoopList = vNewPieces[nPieceN].vPieceLoop[nSI].GetUPointList() ;
-                        for ( auto itSL = SecLevLoopList.begin() ; itSL != SecLevLoopList.end() ; ++ itSL) {
-                           Point3d ptPntSL = itSL->first ;
-                           if ( IsPointInsidePolyLine( ptPntSL, vNewPieces.back().vPieceLoop.back())) {
-                              vSecondLevel.emplace_back( nSI) ;
-                              break ;
-                           }
-                        }
-                     }
-                     // Aggiungo i loop al nuovo pezzo e li tolgo dal precedente.
-                     for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
-                        vNewPieces.back().vPieceLoop.emplace_back( vNewPieces[nPieceN].vPieceLoop[vSecondLevel[nSI]]) ;
-                     for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
-                        vNewPieces[nPieceN].vPieceLoop.erase( vNewPieces[nPieceN].vPieceLoop.begin() + vSecondLevel[nSI]) ;
-                     break ;
-                  }
-                  else {
-                     // Aggiungo loop al pezzo.
-                     vNewPieces[nPieceN].nPiecePart = - 1 ;
-                     vNewPieces[nPieceN].vPieceLoop.emplace_back( CurInnerLoop) ;
-                     vNewPieces[nPieceN].vPieceLoop.back().Invert() ;
-                     // Aggiungo nuovo pezzo.
-                     vNewPieces.emplace_back() ;
-                     vNewPieces.back().vPieceLoop.emplace_back( CurInnerLoop) ;
-                     vNewPieces.back().nPiecePart = 1 ;
-                     // Cerco loop interni a quello appena aggiunto
-                     INTVECTOR vSecondLevel ;
-                     for ( int nSI = 1 ; nSI < int( vNewPieces[nPieceN].vPieceLoop.size()) ; ++ nSI) {
-                        PNTULIST& SecLevLoopList = vNewPieces[nPieceN].vPieceLoop[nSI].GetUPointList() ;
-                        for ( auto itSL = SecLevLoopList.begin() ; itSL != SecLevLoopList.end() ; ++ itSL) {
-                           Point3d ptPntSL = itSL->first ;
-                           if ( IsPointInsidePolyLine( ptPntSL, vNewPieces.back().vPieceLoop.back())) {
-                              vSecondLevel.emplace_back( nSI) ;
-                              break ;
-                           }
-                        }
-                     }
-                     // Aggiungo i loop al nuovo pezzo e li tolgo dal precedente.
-                     for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
-                        vNewPieces.back().vPieceLoop.emplace_back( vNewPieces[nPieceN].vPieceLoop[vSecondLevel[nSI]]) ;
-                     for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
-                        vNewPieces[nPieceN].vPieceLoop.erase( vNewPieces[nPieceN].vPieceLoop.begin() + vSecondLevel[nSI]) ;
-                     break ;
+                  double dPieceArea ;
+                  vNewPieces[nPieceN].vPieceLoop[0].IsClosedAndFlat( Plane3d(), dPieceArea) ;
+                  if ( vNewPieces[nPieceN].vPieceLoop[0].IsClosedAndFlat( Plane3d(), dPieceArea)  &&  dPieceArea < dIncluderPieceArea) {
+                     nIncluderPiece = nPieceN ;
+                     Polygon3d AuxPolygon ;
+                     AuxPolygon.FromPolyLine( CurInnerLoop) ;
+                     Vector3d vtInnLoopNorm =  AuxPolygon.GetVersN() ;
+                     bNewPieceOut = vtFacetNorm * vtInnLoopNorm < 0. ;
                   }
                }
             }
          }
+
+         if ( nIncluderPiece != - 1  &&  bNewPieceOut) {
+            // Aggiungo loop al pezzo.
+            vNewPieces[nIncluderPiece].nPiecePart = 1 ;
+            vNewPieces[nIncluderPiece].vPieceLoop.emplace_back( CurInnerLoop) ;
+            // Aggiungo nuovo pezzo.
+            vNewPieces.emplace_back() ;
+            vNewPieces.back().vPieceLoop.emplace_back( CurInnerLoop) ;
+            vNewPieces.back().vPieceLoop.back().Invert() ;
+            vNewPieces.back().nPiecePart = - 1 ;
+            // Cerco loop interni a quello appena aggiunto
+            INTVECTOR vSecondLevel ;
+            for ( int nSI = 1 ; nSI < int( vNewPieces[nIncluderPiece].vPieceLoop.size()) ; ++ nSI) {
+               PNTULIST& SecLevLoopList = vNewPieces[nIncluderPiece].vPieceLoop[nSI].GetUPointList() ;
+               for ( auto itSL = SecLevLoopList.begin() ; itSL != SecLevLoopList.end() ; ++ itSL) {
+                  Point3d ptPntSL = itSL->first ;
+                  if ( IsPointInsidePolyLine( ptPntSL, vNewPieces.back().vPieceLoop.back())) {
+                     vSecondLevel.emplace_back( nSI) ;
+                     break ;
+                  }
+               }
+            }
+            // Aggiungo i loop al nuovo pezzo e li tolgo dal precedente.
+            for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
+               vNewPieces.back().vPieceLoop.emplace_back( vNewPieces[nIncluderPiece].vPieceLoop[vSecondLevel[nSI]]) ;
+            for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
+               vNewPieces[nIncluderPiece].vPieceLoop.erase( vNewPieces[nIncluderPiece].vPieceLoop.begin() + vSecondLevel[nSI]) ;
+         }
+         else {
+            // Aggiungo loop al pezzo.
+            vNewPieces[nIncluderPiece].nPiecePart = - 1 ;
+            vNewPieces[nIncluderPiece].vPieceLoop.emplace_back( CurInnerLoop) ;
+            vNewPieces[nIncluderPiece].vPieceLoop.back().Invert() ;
+            // Aggiungo nuovo pezzo.
+            vNewPieces.emplace_back() ;
+            vNewPieces.back().vPieceLoop.emplace_back( CurInnerLoop) ;
+            vNewPieces.back().nPiecePart = 1 ;
+            // Cerco loop interni a quello appena aggiunto
+            INTVECTOR vSecondLevel ;
+            for ( int nSI = 1 ; nSI < int( vNewPieces[nIncluderPiece].vPieceLoop.size()) ; ++ nSI) {
+               PNTULIST& SecLevLoopList = vNewPieces[nIncluderPiece].vPieceLoop[nSI].GetUPointList() ;
+               for ( auto itSL = SecLevLoopList.begin() ; itSL != SecLevLoopList.end() ; ++ itSL) {
+                  Point3d ptPntSL = itSL->first ;
+                  if ( IsPointInsidePolyLine( ptPntSL, vNewPieces.back().vPieceLoop.back())) {
+                     vSecondLevel.emplace_back( nSI) ;
+                     break ;
+                  }
+               }
+            }
+            // Aggiungo i loop al nuovo pezzo e li tolgo dal precedente.
+            for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
+               vNewPieces.back().vPieceLoop.emplace_back( vNewPieces[nIncluderPiece].vPieceLoop[vSecondLevel[nSI]]) ;
+            for ( int nSI = 0 ; nSI < int( vSecondLevel.size()) ; ++ nSI)
+               vNewPieces[nIncluderPiece].vPieceLoop.erase( vNewPieces[nIncluderPiece].vPieceLoop.begin() + vSecondLevel[nSI]) ;
+         }
       }
       // Aggiungo al loop esterno i punti dei loop interni che lo toccano.
       // Ciclo sui pezzi della faccia.
+      int nPieceNum = int( vNewPieces.size()) ;
       for ( int nPieceN = 0 ; nPieceN < nPieceNum ; ++ nPieceN) {
          // Ciclo sui segmenti del loop esterno.
          PNTULIST& ExtLoopList = vNewPieces[nPieceN].vPieceLoop[0].GetUPointList() ;