diff --git a/EXE_GdbGetSurf.cpp b/EXE_GdbGetSurf.cpp
index 4451afe..ea2bb9f 100644
--- a/EXE_GdbGetSurf.cpp
+++ b/EXE_GdbGetSurf.cpp
@@ -29,6 +29,7 @@
 #include "/EgtDev/Include/EGkSurfFlatRegion.h"
 #include "/EgtDev/Include/EGkSurfTriMesh.h"
 #include "/EgtDev/Include/EGkSurfBezier.h"
+#include "/EgtDev/Include/EGkDistPointSurfFr.h"
 #include "/EgtDev/Include/EGkDistPointSurfTm.h"
 #include "/EgtDev/Include/EGkIntersCurves.h"
 #include "/EgtDev/Include/EGkIntersLineBox.h"
@@ -119,17 +120,19 @@ bool
 ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist)
 {
    IGeomDB* pGeomDB = GetCurrGeomDB() ;
-   VERIFY_GEOMDB( pGeomDB, GDB_ID_NULL)
+   VERIFY_GEOMDB( pGeomDB, false)
   // recupero la prima superficie FlatRegion
-   ISurfFlatRegion* pSfr1 = GetSurfFlatRegion( pGeomDB->GetGeoObj( nId1)) ;
+   const ISurfFlatRegion* pSfr1 = GetSurfFlatRegion( pGeomDB->GetGeoObj( nId1)) ;
    if ( pSfr1 == nullptr)
       return false ;
   // se richiesta distanza di sicurezza, ne faccio l'offset
-   PtrOwner<ISurfFlatRegion> pSfr1O( pSfr1->Clone()) ;
-   if ( IsNull( pSfr1O))
-      return false ;
-   if ( dMinDist > 10 * EPS_SMALL)
-      pSfr1O->Offset( dMinDist, ICurve::OFF_FILLET) ;
+   PtrOwner<ISurfFlatRegion> pSfr1O ;
+   if ( abs( dMinDist) > 5 * EPS_SMALL) {
+      pSfr1O.Set( pSfr1->Clone()) ;
+      if ( IsNull( pSfr1O)  ||  ! pSfr1O->Offset( dMinDist, ICurve::OFF_FILLET))
+         return false ;
+      pSfr1 = Get( pSfr1O) ;
+   }
   // recupero il riferimento della superficie
    Frame3d frSurf1 ;
    if ( ! pGeomDB->GetGlobFrame( nId1, frSurf1))
@@ -144,9 +147,9 @@ ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist)
       if ( pSfr2L == nullptr)
          return false ;
      // eseguo il test di intersezione tra le due regioni
-      for ( int i = 0 ; i < pSfr1O->GetChunkCount() ; ++ i) {
+      for ( int i = 0 ; i < pSfr1->GetChunkCount() ; ++ i) {
          for ( int j = 0 ; j < pSfr2L->GetChunkCount() ; ++ j) {
-            if ( pSfr1O->GetChunkSimpleClassification( i, *pSfr2L, j) != REGC_OUT)
+            if ( pSfr1->GetChunkSimpleClassification( i, *pSfr2L, j) != REGC_OUT)
                return false ;
          }
       }
@@ -160,8 +163,8 @@ ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist)
       if ( pCrv2L == nullptr)
          return false ;
      // eseguo il test di intersezione tra regione e curva
-      for ( int i = 0 ; i < pSfr1O->GetChunkCount() ; ++ i) {
-         PtrOwner<ICurve> pCrv1( pSfr1O->GetLoop( i, 0)) ;
+      for ( int i = 0 ; i < pSfr1->GetChunkCount() ; ++ i) {
+         PtrOwner<ICurve> pCrv1( pSfr1->GetLoop( i, 0)) ;
          if ( pCrv1 == nullptr)
             return false ;
          IntersCurveCurve ccInt( *pCrv1, *pCrv2L) ;
@@ -169,7 +172,8 @@ ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist)
          if ( ! ccInt.GetCurveClassification( 1, EPS_SMALL, vcClass)  ||  vcClass.empty())
             return false ;
          for ( auto& cClass : vcClass) {
-            if ( cClass.nClass == CRVC_IN  ||  cClass.nClass == CRVC_NULL)
+            if ( cClass.nClass == CRVC_IN  ||  cClass.nClass == CRVC_ON_M  ||
+                 cClass.nClass == CRVC_ON_P  ||  cClass.nClass == CRVC_NULL)
                return false ;
          }
       }
@@ -179,34 +183,17 @@ ExeSurfFrTestExternal( int nId1, int nId2, double dMinDist)
    else if ( nType2 == GEO_PNT3D) {
      // recupero il punto
       IGeoPoint3d* pGeoPt = GetGeoPoint3d( pGeomDB->GetGeoObj( nId2)) ;      
-      Point3d pt = pGeoPt->GetPoint() ;
+      Point3d ptP = pGeoPt->GetPoint() ;
      // porto il punto in locale
       Frame3d frPt ;
       if ( ! pGeomDB->GetGlobFrame( nId2, frPt))
          return false ;
-      pt.LocToLoc( frPt, frSurf1) ;
-     
-      for ( int i = 0 ; i < pSfr1O->GetChunkCount() ; i ++) {
-        // verifico se è contenuto nel loop esterno
-         PtrOwner<ICurve> pCrv( pSfr1O->GetLoop( i, 0)) ;
-         PolyLine PL ;
-         pCrv->ApproxWithLines( 10 * EPS_SMALL, 15, ICurve::APL_STD, PL) ;
-         if ( IsPointInsidePolyLine( pt, PL, EPS_SMALL)) {
-            bool bInsideHole = false ;
-           // verifico se è contenuto in un loop interno
-            for ( int j = 1 ; j < pSfr1O->GetLoopCount( i) ; j ++) {
-               PtrOwner<ICurve> pCrv( pSfr1O->GetLoop( i, j)) ;
-               pCrv->ApproxWithLines( 10 * EPS_SMALL, 15, ICurve::APL_STD, PL) ;
-               PL.Invert() ;
-               if ( IsPointInsidePolyLine( pt, PL, EPS_SMALL))
-                  bInsideHole = true ;
-            }
-           // se è contenuto nel loop esterno ma non è contenuto in nessuno dei loop interni allora il punto è interno
-            if ( ! bInsideHole)
-               return false ;
-         }         
-      }
-      return true ;
+      ptP.LocToLoc( frPt, frSurf1) ;
+     // determino se interno (comprende la frontiera)
+      bool bInside ;
+      if ( ! IsPointInsideSurfFr( ptP, pSfr1, 0, bInside))
+         return false ;
+      return ( ! bInside) ;
    }
   // altrimenti non valida
    else
diff --git a/EXE_GdbModifySurf.cpp b/EXE_GdbModifySurf.cpp
index 4e4d3cf..4bbbc5f 100644
--- a/EXE_GdbModifySurf.cpp
+++ b/EXE_GdbModifySurf.cpp
@@ -324,7 +324,7 @@ ExeSurfFrSubtract( int nId1, int nId2)
   // eseguo la sottrazione della seconda superficie dalla prima
    bOk = bOk && pSfr1->Subtract( *pSfr2L) ;
   // se il risultato è vuoto, cancello la FlatRegion
-   if ( bOk  && ! pSfr1->IsValid())
+   if ( bOk  &&  ! pSfr1->IsValid())
       pGeomDB->Erase( nId1) ;
    ExeSetModified() ;
   // se richiesto, salvo il comando Lua equivalente
@@ -356,7 +356,7 @@ ExeSurfFrIntersect( int nId1, int nId2)
   // eseguo l'intersezione tra le due superfici
    bOk = bOk && pSfr1->Intersect( *pSfr2L) ;
   // se il risultato è vuoto, cancello la FlatRegion
-   if ( bOk  && ! pSfr1->IsValid())
+   if ( bOk  &&  ! pSfr1->IsValid())
       pGeomDB->Erase( nId1) ;
    ExeSetModified() ;
   // se richiesto, salvo il comando Lua equivalente
@@ -381,7 +381,7 @@ ExeSurfFrOffset( int nId, double dDist, int nType)
   // eseguo l'offset
    bOk = bOk && pSfr->Offset( dDist, nType) ;
   // se il risultato è vuoto, cancello la FlatRegion
-   if ( bOk  && ! pSfr->IsValid())
+   if ( bOk  &&  ! pSfr->IsValid())
       pGeomDB->Erase( nId) ;
    ExeSetModified() ;
   // se richiesto, salvo il comando Lua equivalente
@@ -400,7 +400,7 @@ bool
 ExeSurfFrOffsetAdv( int nId, double dDist, int nType, int& nNewId)
 {
    IGeomDB* pGeomDB = GetCurrGeomDB() ;
-   VERIFY_GEOMDB( pGeomDB, GDB_ID_NULL)
+   VERIFY_GEOMDB( pGeomDB, false)
   // recupero la superficie FlatRegion
    ISurfFlatRegion* pSfr = GetSurfFlatRegion( pGeomDB->GetGeoObj( nId)) ;
    if ( pSfr == nullptr)
@@ -421,6 +421,32 @@ ExeSurfFrOffsetAdv( int nId, double dDist, int nType, int& nNewId)
    return true ;
 }
 
+//----------------------------------------------------------------------------
+bool
+ExeSurfFrEraseChunk( int nId, int nChunk)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, false)
+  // recupero la superficie FlatRegion
+   ISurfFlatRegion* pSfr = GetSurfFlatRegion( pGeomDB->GetGeoObj( nId)) ;
+   if ( pSfr == nullptr)
+      return false ;      
+  // elimino il chunk indicato
+   bool bOk = pSfr->EraseChunk( nChunk) ;
+  // se il risultato è vuoto, cancello la FlatRegion
+   if ( bOk  &&  ! pSfr->IsValid())
+      pGeomDB->Erase( nId) ;
+   ExeSetModified() ;
+  // se richiesto, salvo il comando Lua equivalente
+   if ( IsCmdLog()) {
+      string sLua = "EgtSurfFrEraseChunk(" + ToString( nId) + "," +
+                                             ToString( nChunk) + ")" +
+                    " -- Ok=" + ToString( bOk) ;
+      LOG_INFO( GetCmdLogger(), sLua.c_str()) ;
+   }
+   return bOk ;
+}
+
 //----------------------------------------------------------------------------
 bool
 ExeSurfFrMoveSimpleNoCollision( int nId1, int nId2, const Vector3d& vtDir, double& dLen, int nRefType)
diff --git a/EgtExecutor.rc b/EgtExecutor.rc
index 983c7e1..758211a 100644
Binary files a/EgtExecutor.rc and b/EgtExecutor.rc differ
diff --git a/LUA_GdbModifySurf.cpp b/LUA_GdbModifySurf.cpp
index 34802cd..fd7c10e 100644
--- a/LUA_GdbModifySurf.cpp
+++ b/LUA_GdbModifySurf.cpp
@@ -165,6 +165,24 @@ LuaSurfFrOffsetAdv( lua_State* L)
    return 1 ;
 }
 
+//-------------------------------------------------------------------------------
+static int
+LuaSurfFrEraseChunk( lua_State* L)
+{
+  // 2 parametri : Id, nChunk
+   int nId ;
+   LuaCheckParam( L, 1, nId)
+   int nChunk ;
+   LuaCheckParam( L, 2, nChunk)
+   LuaClearStack( L) ;
+  // eseguo l'offset della regione
+   int nNewId = GDB_ID_NULL ;
+   bool bOk = ExeSurfFrEraseChunk( nId, nChunk) ;
+   LuaSetParam( L, bOk) ;
+
+   return 1 ;
+}
+
 //----------------------------------------------------------------------------
 static int
 LuaSurfTmMoveVertex( lua_State* L)
@@ -611,6 +629,7 @@ LuaInstallGdbModifySurf( LuaMgr& luaMgr)
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfFrIntersect", LuaSurfFrIntersect) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfFrOffset", LuaSurfFrOffset) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfFrOffsetAdv", LuaSurfFrOffsetAdv) ;
+   bOk = bOk && luaMgr.RegisterFunction( "EgtSurfFrEraseChunk", LuaSurfFrEraseChunk) ;
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfTmMoveVertex", LuaSurfTmMoveVertex) ;  
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfTmMoveFacet", LuaSurfTmMoveFacet) ;  
    bOk = bOk && luaMgr.RegisterFunction( "EgtSurfTmToTriangles", LuaSurfTmToTriangles) ;