diff --git a/MachMgrRawParts.cpp b/MachMgrRawParts.cpp
index 4a4873d..e92f27c 100644
--- a/MachMgrRawParts.cpp
+++ b/MachMgrRawParts.cpp
@@ -625,6 +625,7 @@ MachMgr::VerifyRawPartPhase( int nRawId, int nPhase) const
    INTVECTOR vPhase ;
    if ( ! GetRawPartPhases( nRawId, vPhase))
       return false ;
+  // verifico presenza nella fase indicata
    return ( find( vPhase.begin(), vPhase.end(), nPhase) != vPhase.end()) ;
 }
 
diff --git a/Operation.cpp b/Operation.cpp
index 0f546e4..8a9791a 100644
--- a/Operation.cpp
+++ b/Operation.cpp
@@ -32,6 +32,7 @@
 #include "/EgtDev/Include/EGkGeomDB.h"
 #include "/EgtDev/Include/EGkCDeBoxClosedSurfTm.h"
 #include "/EgtDev/Include/EGkCDeCylClosedSurfTm.h"
+#include "/EgtDev/Include/EGkCAvToolSurfTm.h"
 #include "/EgtDev/Include/EGkStringUtils3d.h"
 #include "/EgtDev/Include/EXeConst.h"
 #include "/EgtDev/Include/EgtNumUtils.h"
@@ -377,6 +378,8 @@ Operation::GetElevation( int nPhase, const Point3d& ptP1, const Point3d& ptP2, c
    return true ;
 }
 
+#if 1
+
 //----------------------------------------------------------------------------
 bool
 Operation::GetElevation( int nPhase, const Point3d& ptP, const Vector3d& vtTool, double dRad,
@@ -457,6 +460,102 @@ Operation::GetElevation( int nPhase, const Point3d& ptP, const Vector3d& vtTool,
    return true ;
 }
 
+#else
+
+//----------------------------------------------------------------------------
+bool
+Operation::GetElevation( int nPhase, const Point3d& ptP, const Vector3d& vtTool, double dRad,
+                         const Vector3d& vtDir, double& dElev) const
+{
+   const double STD_TOOL_LEN = 100 ;
+   return GetElevation( nPhase, ptP, vtTool, dRad, STD_TOOL_LEN, vtDir, dElev) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+Operation::GetElevation( int nPhase, const Point3d& ptP, const Vector3d& vtTool, double dRad, double dLen,
+                         const Vector3d& vtDir, double& dElev) const
+{
+  // risultato di default
+   dElev = 0 ;
+  // verifico oggetti base
+   if ( m_pMchMgr == nullptr  ||  m_pGeomDB == nullptr)
+      return false ;
+  // inizializzo elevazioni per ogni grezzo
+   INTDBLVECTOR vRawElev ;
+  // ciclo sui grezzi della fase
+   int nRawId = m_pMchMgr->GetFirstRawPart() ;
+   while ( nRawId != GDB_ID_NULL) {
+     // verifico che il grezzo compaia nella fase
+      if ( m_pMchMgr->VerifyRawPartPhase( nRawId, nPhase)) {
+        // recupero la trimesh del grezzo
+         int nStmId = m_pGeomDB->GetFirstNameInGroup( nRawId, MACH_RAW_SOLID) ;
+         ISurfTriMesh* pStm = GetSurfTriMesh( m_pGeomDB->GetGeoObj( nStmId)) ;
+         if ( pStm != nullptr) {
+           // recupero il riferimento della trimesh
+            Frame3d frStm ;
+            m_pGeomDB->GetGlobFrame( nStmId, frStm) ;
+           // porto posizione e direzioni in questo riferimento
+            Point3d ptPL = GetToLoc( ptP, frStm) ;
+            Vector3d vtToolL = GetToLoc( vtTool, frStm) ;
+            Vector3d vtDirL = GetToLoc( vtDir, frStm) ;
+           // determino quanto allontanarsi
+            PtrOwner<ICAvToolSurfTm> pCAvTlStm( CreateCAvToolSurfTm()) ;
+            if ( IsNull( pCAvTlStm))
+               return false ;
+            pCAvTlStm->SetStdTool( dLen, dRad, 0) ;
+            pCAvTlStm->SetSurfTm( *pStm) ;
+            double dDist = 0 ;
+            // per Collision Avoid il punto di riferimento non è il tip dell'utensile ma il naso mandrino
+            if ( ! pCAvTlStm->TestPosition( ptPL + dLen * vtToolL, vtToolL, vtDirL, dDist))
+               return false ;
+            if ( dDist > 0)
+               vRawElev.emplace_back( nStmId, dDist) ;
+         }
+      }
+     // passo al grezzo successivo
+      nRawId = m_pMchMgr->GetNextRawPart( nRawId) ;
+   }
+  // se trovate elevazioni
+   if ( ! vRawElev.empty()) {
+     // ordino il vettore secondo l'elevazione crescente
+      sort( vRawElev.begin(), vRawElev.end(), []( const INTDBL& a, const INTDBL& b)
+                                                  { return a.second < b.second ; }) ;
+     // box dell'utensile nella posizione iniziale
+      BBox3d b3Tool ;
+      b3Tool.Add( ptP) ;
+      b3Tool.Add( ptP + dLen * vtTool) ;
+      if ( vtTool.IsX())
+         b3Tool.Expand( 0, dRad, dRad) ;
+      else if ( vtTool.IsY())
+         b3Tool.Expand( dRad, 0, dRad) ;
+      else if ( vtTool.IsZ())
+         b3Tool.Expand( dRad, dRad, 0) ;
+      else {
+         double dExpandX = dRad * sqrt( 1 - vtTool.x * vtTool.x) ;
+         double dExpandY = dRad * sqrt( 1 - vtTool.y * vtTool.y) ;
+         double dExpandZ = dRad * sqrt( 1 - vtTool.z * vtTool.z) ;
+         b3Tool.Expand( dExpandX, dExpandY, dExpandZ) ;
+      }
+      b3Tool.Expand( MAX_DIST_RAW) ;
+     // verifico la reale interferenza dell'utensile con i diversi grezzi
+      for ( int i = 0 ; i < vRawElev.size() ; ++ i) {
+        // box del grezzo
+         BBox3d b3Raw ; 
+         m_pGeomDB->GetGlobalBBox( vRawElev[i].first, b3Raw) ;
+        // confronto con il box dell'utensile nella posizione precedente
+         BBox3d b3CurrTool = b3Tool ;
+         b3CurrTool.Translate( dElev * vtDir) ;
+         if ( b3Raw.Overlaps( b3CurrTool))
+            dElev = vRawElev[i].second ;
+      }
+   }
+
+   return true ;
+}
+
+#endif
+
 //----------------------------------------------------------------------------
 bool
 Operation::GetAhPointUnderRaw( const Point3d& ptP, const Vector3d& vtTool, double dToolRad, double dToolRadForElev,