diff --git a/EXE_GdbModifyCurve.cpp b/EXE_GdbModifyCurve.cpp
index 6f64eeb..242e25f 100644
--- a/EXE_GdbModifyCurve.cpp
+++ b/EXE_GdbModifyCurve.cpp
@@ -1013,6 +1013,23 @@ ExeModifyCurveCompoJoint( int nId, int nU, const Point3d& ptP, int nRefType)
    return bOk ;
 }
 
+//-------------------------------------------------------------------------------
+int
+ExeGetCurveCompoJointCount( int nId)
+{
+   IGeomDB* pGeomDB = GetCurrGeomDB() ;
+   VERIFY_GEOMDB( pGeomDB, 0)
+  // recupero la curva composita
+   ICurveComposite* pCompo = GetCurveComposite( pGeomDB->GetGeoObj( nId)) ;
+   if ( pCompo == nullptr)
+      return 0 ;
+  // calcolo il numero di giunzioni (se chiusa è uguale al numero delle curve altrimenti -1)
+   if ( pCompo->IsClosed())
+      return pCompo->GetCurveCount() ;
+   else
+      return ( pCompo->GetCurveCount() - 1) ;
+}
+
 //-------------------------------------------------------------------------------
 bool
 ExeRemoveCurveCompoJoint( int nId, int nU)
diff --git a/EXE_NstPartNesting.cpp b/EXE_NstPartNesting.cpp
index 1097656..c9e6833 100644
--- a/EXE_NstPartNesting.cpp
+++ b/EXE_NstPartNesting.cpp
@@ -57,7 +57,7 @@ AdjustClusterObjIds( IGeomDB* pGeomDB, const INTVECTOR& vIds, INTVECTOR& vTrueId
    if ( pGeomDB == nullptr)
       return false ;
   // Flag per calcolo box
-   const int BBF_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
   // Risolvo eventuali riferimenti a oggetti selezionati
    vTrueIds.clear() ;
    vTrueIds.reserve( vIds.size()) ;
@@ -66,7 +66,7 @@ AdjustClusterObjIds( IGeomDB* pGeomDB, const INTVECTOR& vIds, INTVECTOR& vTrueId
       int nTrueId = (( nId != GDB_ID_SEL) ? nId : pGeomDB->GetFirstSelectedObj()) ;
       while ( nTrueId != GDB_ID_NULL) {
          BBox3d b3Part ;
-         if ( pGeomDB->GetGlobalBBox( nTrueId, b3Part, BBF_MY_FLAG)) {
+         if ( pGeomDB->GetGlobalBBox( nTrueId, b3Part, BBF_PART_MY_FLAG)) {
            // inserisco l'identificativo nel vettore dei validi
             vTrueIds.push_back( nTrueId) ;
            // aggiorno il box del cluster
@@ -277,7 +277,7 @@ static bool
 MyVerifyPartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, const BBox3d& b3Cluster, bool bReducedCut)
 {
   // Flag per calcolo box
-   const int BBF_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
 
   // Determino le regioni dei pezzi
    INTVECTOR vReg ;
@@ -287,7 +287,7 @@ MyVerifyPartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, const BBox3d&
      // recupero regione del pezzo
       int nRegId = GetFlatPartRegion( pGeomDB, nId) ;
       BBox3d b3Reg ;
-      if ( pGeomDB->GetGlobalBBox( nRegId, b3Reg, BBF_MY_FLAG)) {
+      if ( pGeomDB->GetGlobalBBox( nRegId, b3Reg, BBF_PART_MY_FLAG)) {
          vReg.emplace_back( nRegId) ;
          b3RegCluster.Add( b3Reg) ;
       }
@@ -323,7 +323,7 @@ MyVerifyPartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, const BBox3d&
    while ( nId2 != GDB_ID_NULL) {
       if ( find( vTrueIds.begin(), vTrueIds.end(), nId2) == vTrueIds.end()) {
          BBox3d b3Part2 ;
-         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_MY_FLAG) &&
+         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_PART_MY_FLAG) &&
               b3Cluster.OverlapsXY( b3Part2)) {
            // recupero regione del pezzo
             int nRegId = GetFlatPartRegion( pGeomDB, nId2) ;
@@ -398,7 +398,7 @@ MyPackPartCluster( const INTVECTOR& vTrueIds, bool bReducedCut,
   // Box della regione di interesse
    BBox3d b3Region( dXmin, dYmin, 0, dXmax, dYmax, 0) ;
   // Flag per calcolo box
-   const int BBF_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
 
   // Determino tutti gli altri pezzi compresi nella regione di interesse
    INTVECTOR vOtherIds ;
@@ -406,7 +406,7 @@ MyPackPartCluster( const INTVECTOR& vTrueIds, bool bReducedCut,
    while ( nId2 != GDB_ID_NULL) {
       if ( find( vTrueIds.begin(), vTrueIds.end(), nId2) == vTrueIds.end()) {
          BBox3d b3Part2 ;
-         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_MY_FLAG) &&
+         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_PART_MY_FLAG) &&
               b3Region.OverlapsXY( b3Part2)) {
             vOtherIds.emplace_back( nId2) ;
          }
@@ -515,10 +515,29 @@ ExePackPartCluster( const INTVECTOR& vIds, bool bReducedCut, bool bBottomUp)
       return false ;
    b3Box.Expand( - SPESS, - SPESS, 0) ;
 
+  // Flag per calcolo box
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+
+  // Calcolo il box di ingombro delle regioni dei pezzi
+   BBox3d b3RegCluster ;
+   for ( int nId : vTrueIds) {
+     // recupero regione del pezzo
+      int nRegId = GetFlatPartRegion( pGeomDB, nId) ;
+      BBox3d b3Reg ;
+      if ( pGeomDB->GetGlobalBBox( nRegId, b3Reg, BBF_PART_MY_FLAG)) {
+         b3RegCluster.Add( b3Reg) ;
+      }
+      else
+         return false ;
+   }
+   double dRegClDimX = b3RegCluster.GetMax().x - b3RegCluster.GetMin().x ;
+   double dRegClDimY = b3RegCluster.GetMax().y - b3RegCluster.GetMin().y ;
+
   // Procedo per tentativi
+   const double STEP = 50 ;
    bool bFit = false ;
    Point3d ptOrig = b3Cluster.GetMin() ;
-   Point3d ptLineStart = b3Box.GetMin() ;
+   Point3d ptLineStart = ( bBottomUp ? b3Box.GetMin() : b3Box.GetMax() - Vector3d(0, -dRegClDimY, 0)) ;
    Point3d ptIns = ptLineStart ;
    while ( true) {
      // porto nella posizione di prova
@@ -533,11 +552,11 @@ ExePackPartCluster( const INTVECTOR& vIds, bool bReducedCut, bool bBottomUp)
          break ;
       }
      // nuova posizione di inserimento (incrementando X)
-      ptIns += Vector3d( 50, 0, 0) ;
+      ptIns += Vector3d( STEP, 0, 0) ;
      // se esco dal box torno all'inizio e incremento Y
-      if ( ! b3Box.EnclosesXY( ptIns)) {
-         ptLineStart += Vector3d( 0, 50, 0) ;
-         if ( ( ! b3Box.EnclosesXY( ptLineStart)))
+      if ( ! b3Box.EnclosesXY( ptIns + Vector3d( dRegClDimX, 0, 0))) {
+         ptLineStart += Vector3d( 0, ( bBottomUp ? STEP : - STEP), 0) ;
+         if ( ( ! b3Box.EnclosesXY( ptLineStart + Vector3d( 0, dRegClDimY, 0))))
             break ;
          ptIns = ptLineStart ;
       }
@@ -651,8 +670,8 @@ MyMovePartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, BBox3d b3Cluster
    if ( vtMoveXY.IsSmall())
       return true ;
 
-  // Flag per calcolo box
-   const int BBF_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+  // Flag per calcolo box pezzi
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
 
   // Verifico se pezzi sotto la radice o pezzi in altro gruppo
    int nGroupId = pGeomDB->GetParentId( vTrueIds[0]) ;
@@ -671,7 +690,7 @@ MyMovePartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, BBox3d b3Cluster
    while ( nId2 != GDB_ID_NULL) {
       if ( find( vTrueIds.begin(), vTrueIds.end(), nId2) == vTrueIds.end()) {
          BBox3d b3Part2 ;
-         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_MY_FLAG) &&
+         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_PART_MY_FLAG) &&
               b3Region.OverlapsXY( b3Part2)) {
            // recupero regione del pezzo
             int nRegId = GetFlatPartRegion( pGeomDB, nId2) ;
@@ -821,7 +840,7 @@ MyRotatePartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, BBox3d& b3Clus
   // Rotazione nel piano XY globale
 
   // Flag per calcolo box
-   const int BBF_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
+   const int BBF_PART_MY_FLAG = BBF_ONLY_VISIBLE | BBF_IGNORE_TEXT | BBF_IGNORE_DIM ;
 
   // Verifico se pezzi sotto la radice o pezzi in altro gruppo
    int nGroupId = pGeomDB->GetParentId( vTrueIds[0]) ;
@@ -840,7 +859,7 @@ MyRotatePartCluster( IGeomDB* pGeomDB, const INTVECTOR& vTrueIds, BBox3d& b3Clus
    while ( nId2 != GDB_ID_NULL) {
       if ( find( vTrueIds.begin(), vTrueIds.end(), nId2) == vTrueIds.end()) {
          BBox3d b3Part2 ;
-         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_MY_FLAG) &&
+         if ( pGeomDB->GetGlobalBBox( nId2, b3Part2, BBF_PART_MY_FLAG) &&
               b3Region.OverlapsXY( b3Part2)) {
            // recupero regione del pezzo
             int nRegId = GetFlatPartRegion( pGeomDB, nId2) ;
@@ -990,6 +1009,8 @@ ExeAlignPartClusterOnCollision( const INTVECTOR& vIds, bool bReducedCut, bool& b
    double dU ;
    if ( ! pCrv->GetParamAtPoint( ptCntL, dU, 10 * EPS_SMALL))
       return false ;
+   if ( fabs( dU - round( dU)) < 100 * EPS_PARAM)
+      dU = round( dU) ;
    Point3d ptPp ;
    Vector3d vtTp ;
    if ( ! pCrv->GetPointTang( dU, ICurve::FROM_MINUS, ptPp, vtTp))