diff --git a/OffsetCurve.cpp b/OffsetCurve.cpp
index 9ec0978..466bacb 100644
--- a/OffsetCurve.cpp
+++ b/OffsetCurve.cpp
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
-//  EgalTech 2015-2020
+//  EgalTech 2015-2023
 //----------------------------------------------------------------------------
-// File : OffsetCurve.cpp         Data : 10.10.20         Versione : 2.2j2
+// File : OffsetCurve.cpp         Data : 03.08.23         Versione : 2.5h1
 // Contenuto : Classe per offset avanzato di Curve.
 //
 //
@@ -9,6 +9,7 @@
 // Modifiche : 23.09.15 DS Creazione modulo.
 //             24.06.19 DS Agg. GetShorterCurve.
 //             10.10.20 DS Migliorata gestione angoli interni.
+//             03.08.23 DS Migliorato riconoscimento angoli esterni di valore circa 180deg.
 //
 //----------------------------------------------------------------------------
 
@@ -865,16 +866,30 @@ CalcAngle( const ICurve* pCrv1, const ICurve* pCrv2, double& dAngDeg)
    if ( ! vtDir1.GetAngleXY( vtDir2, dAngDeg))
       return false ;
   // se vicino all'angolo piatto, si devono ricalcolare spostandosi un poco
-   if ( abs( dAngDeg) > ( ANG_STRAIGHT - EPS_ANG_SMALL)) {
-     // eseguo calcolo spostato
+   const double MAX_ANG_DELTA = 2 ;
+   double dAngDelta = abs( abs( dAngDeg) - ANG_STRAIGHT) ;
+   if ( dAngDelta < MAX_ANG_DELTA) {
+     // angolo al centro delle curve
+      double dAngCen1 = 0 ;
+      if ( pCrv1->GetType() == CRV_ARC)
+         dAngCen1 = abs( GetBasicCurveArc( pCrv1)->GetAngCenter()) ;
+      double dAngCen2 = 0 ;
+      if ( pCrv2->GetType() == CRV_ARC)
+         dAngCen2 = abs( GetBasicCurveArc( pCrv2)->GetAngCenter()) ;
+     // determino posizioni spostate
       double dU1 = 1 ;
+      if ( dAngCen1 > EPS_ANG_SMALL) {
+         dU1 = 1 - min( 1.1 * dAngDelta / ( dAngCen1 + dAngCen2), 0.5) ;
+      }
       double dU2 = 0 ;
+      if ( dAngCen2 > EPS_ANG_SMALL) {
+         dU2 = 0 + min( 1.1 * dAngDelta / ( dAngCen1 + dAngCen2), 0.5) ;
+      }
+     // eseguo calcolo spostato
       Point3d ptDummy ;
       Vector3d vtDir1b ;
       Vector3d vtDir2b ;
-      if ( ! MoveParamToAvoidTg( dU1, ICurve::FROM_MINUS, *pCrv1)  ||
-           ! pCrv1->GetPointTang( dU1, ICurve::FROM_MINUS, ptDummy, vtDir1b)  ||
-           ! MoveParamToAvoidTg( dU2, ICurve::FROM_PLUS, *pCrv2)  ||
+      if ( ! pCrv1->GetPointTang( dU1, ICurve::FROM_MINUS, ptDummy, vtDir1b)  ||
            ! pCrv2->GetPointTang( dU2, ICurve::FROM_PLUS, ptDummy, vtDir2b))
          return false ;
       if ( ! vtDir1b.GetAngleXY( vtDir2b, dAngDeg))
diff --git a/SurfFlatRegion.cpp b/SurfFlatRegion.cpp
index 69a2942..da62396 100644
--- a/SurfFlatRegion.cpp
+++ b/SurfFlatRegion.cpp
@@ -597,7 +597,7 @@ SurfFlatRegion::GetBBox( const Frame3d& frRef, BBox3d& b3Ref, int nFlag) const
   // è il bounding box dei loop esterni
    for ( auto i : m_vExtInd) {
       BBox3d b3Tmp ;
-      if ( m_vpLoop[i]->GetBBox( frCompo, b3Ref, nFlag))
+      if ( m_vpLoop[i]->GetBBox( frCompo, b3Tmp, nFlag))
          b3Ref.Add( b3Tmp) ;
    }
    return ( ! b3Ref.IsEmpty()) ;