diff --git a/NgeConst.h b/NgeConst.h
index ee496b4..a97a35c 100644
--- a/NgeConst.h
+++ b/NgeConst.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
 //  EgalTech 2014-2020
 //----------------------------------------------------------------------------
-// File : NgeConst.h           Data : 22.03.20          Versione : 2.2c3
+// File : NgeConst.h           Data : 22.09.20          Versione : 2.2i2
 // Contenuto : Costanti per file Nge.
 //
 //
@@ -17,6 +17,7 @@
 //             18.09.18 DS 1014 -> Aggiunto flag Shape a Zmap.
 //             27.12.19 DS 1015 -> Aggiunto DIMENSION.
 //             22.03.20 DS 1016 -> Aggiunta SurfBezier.
+//             22.09.20 DS 1018 -> Aggiunto DexVoxRatio a Zmap.
 //
 //----------------------------------------------------------------------------
 
@@ -40,7 +41,8 @@ const int NGE_VER_1013 = 1013 ;             // aggiunto TextureData (Keyword T)
 const int NGE_VER_1014 = 1014 ;             // aggiunto Shape a Zmap
 const int NGE_VER_1015 = 1015 ;             // aggiunto Dimension
 const int NGE_VER_1016 = 1016 ;             // aggiunta superficie Bezier
-const int NGE_VER_LAST = NGE_VER_1016 ;
+const int NGE_VER_1018 = 1018 ;             // aggiunto DexVoxRatio a Zmap
+const int NGE_VER_LAST = NGE_VER_1018 ;
 // Indici KeyWord
 const int NGE_START   =  0 ;
 const int NGE_END     =  1 ;
diff --git a/VolZmap.cpp b/VolZmap.cpp
index f8736aa..aff5663 100644
--- a/VolZmap.cpp
+++ b/VolZmap.cpp
@@ -212,6 +212,8 @@ VolZmap::Dump( string& sOut, bool bMM, const char* szNewLine) const
   // numero di blocchi
    sOut += "Blocks=" + ToString( m_nNumBlock) + " (" + ToString( m_nFracLin[0]) + "x" +
            ToString( m_nFracLin[1]) + "x" + ToString( m_nFracLin[2]) + ")" + szNewLine ;
+  // dexel per voxel (DexToVoxRatio)
+   sOut += "DexVoxRat=" + ToString( m_nDexVoxRatio) + szNewLine ;
 
    return true ;
 }
@@ -233,7 +235,7 @@ VolZmap::Save( NgeWriter& ngeOut) const
   // numero di blocchi
    if ( ! ngeOut.WriteInt( m_nNumBlock, ",", false))
       return false ;
-  // numero di dexel per blocco
+  // numero di voxel per blocco
    if ( ! ngeOut.WriteInt( m_nVoxNumPerBlock, ",", false))
       return false ;
   // numero di blocchi per ogni asse 
@@ -241,6 +243,9 @@ VolZmap::Save( NgeWriter& ngeOut) const
       if ( ! ngeOut.WriteInt( m_nFracLin[i], ",", false))
          return false ;
    }
+  // DexVoxRatio
+   if ( ! ngeOut.WriteInt( m_nDexVoxRatio, ",", false))
+      return false ;
   // numero di componenti connesse
    if ( ! ngeOut.WriteInt( m_nConnectedCompoCount, ",", false))
       return false ;
@@ -253,7 +258,7 @@ VolZmap::Save( NgeWriter& ngeOut) const
   // sistema di riferimento
    if ( ! ngeOut.WriteFrame( m_MapFrame, ";", true))
       return false ;   
-  // per ogni mappa : numero di passi in X e Y e quote z estremali
+  // per ogni mappa : numero di passi in X e Y e quote Z estremali
    for ( int i = 0 ; i < m_nMapNum ; ++ i) {
       if ( ! ngeOut.WriteInt( m_nNx[i], ",", false))
          return false ;
@@ -313,7 +318,7 @@ VolZmap::Load( NgeReader& ngeIn)
   // numero di blocchi
    if ( ! ngeIn.ReadInt( m_nNumBlock, ",", false))
       return false ;
-  // numero di dexel per blocco
+  // numero di voxel per blocco
    if ( ! ngeIn.ReadInt( m_nVoxNumPerBlock, ",", false))
       return false ;
   // numero di blocchi per ogni asse 
@@ -321,6 +326,11 @@ VolZmap::Load( NgeReader& ngeIn)
       if ( ! ngeIn.ReadInt( m_nFracLin[i], ",", false))
          return false ;
    }     
+  // da versione 1018 : aggiunto DexVoxRatio
+   if ( ngeIn.GetFileVersion() >= NGE_VER_1018) {
+      if ( ! ngeIn.ReadInt( m_nDexVoxRatio, ",", false))
+         return false ;
+   }
   // numero di componenti connesse
    if ( ! ngeIn.ReadInt( m_nConnectedCompoCount, ",", false))
       return false ;
@@ -335,7 +345,7 @@ VolZmap::Load( NgeReader& ngeIn)
   // sistema di riferimento
    if ( ! ngeIn.ReadFrame( m_MapFrame, ";", true))
          return false ;
-  // per ogni mappa : numero di passi in X e Y e quote z estremali
+  // per ogni mappa : numero di passi in X e Y e quote Z estremali
    for ( int i = 0 ; i < m_nMapNum ; ++ i) {
       if ( ! ngeIn.ReadInt( m_nNx[i], ",", false))
          return false ;
@@ -1814,16 +1824,17 @@ VolZmap::Compact( void)
 bool
 VolZmap::ChangeResolution( int nDexVoxRatio)
 {
-   if ( nDexVoxRatio < 1  ||  nDexVoxRatio > 2)
+   if ( nDexVoxRatio < 1  ||  nDexVoxRatio > 5)
       return false ;
    if ( nDexVoxRatio != m_nDexVoxRatio) {
+      int nOldDexVoxRatio = m_nDexVoxRatio ;
       m_nDexVoxRatio = nDexVoxRatio ;
       if ( CalcBlockNum()) {
          ResetGraphics() ;
          m_OGrMgr.Clear() ;
          return true ;
       }
-      m_nDexVoxRatio = ( m_nDexVoxRatio == 1 ? 2 : 1) ;
+      m_nDexVoxRatio = nOldDexVoxRatio ;
       return false ;
    }
    return true ;
@@ -1873,7 +1884,7 @@ VolZmap::CalcBlockNum( void)
 
 //----------------------------------------------------------------------------
 bool 
-VolZmap::SetTolerances( double dLinTol, double dAngTolDeg) 
+VolZmap::SetToolTolerances( double dLinTol, double dAngTolDeg) 
 {
    return m_Tool.SetTolerances( dLinTol, dAngTolDeg) ;
 }
diff --git a/VolZmap.h b/VolZmap.h
index a59a080..7145430 100644
--- a/VolZmap.h
+++ b/VolZmap.h
@@ -75,7 +75,10 @@ class VolZmap : public IVolZmap, public IGeoObjRW
       bool GetEdges( ICURVEPOVECTOR& vpCurve) const override ;
       bool GetVolume( double& dVol) const override ;
       bool GetDexelLines( int nDir, int nPos1, int nPos2, POLYLINELIST& lstPL) const override ;
-      bool SetTolerances( double dLinTol, double dAngTolDeg = 90) override ;
+      int  GetResolution( void) const override
+              { return m_nDexVoxRatio ; }   
+      bool ChangeResolution( int nDexVoxRatio) override ;
+      bool SetToolTolerances( double dLinTol, double dAngTolDeg = 90) override ;
       bool SetStdTool( const std::string& sToolName, double dH, double dR, double dCornR, double dCutterH, int nFlag) override ;
       bool SetAdvTool( const std::string& sToolName,
                        double dH, double dR, double dTipH, double dTipR, double dCornR, double dCutterH, int nFlag) override ;
@@ -104,8 +107,7 @@ class VolZmap : public IVolZmap, public IGeoObjRW
       bool GetPartBBox( int nPart, const Frame3d& frRef, BBox3d& b3Ref, int nFlag = BBF_STANDARD) const override ;
       VolZmap* ClonePart( int nPart) const override ;
       bool RemovePart( int nPart) override ;
-      int GetPartMinDistFromPoint( const Point3d& ptP) const override ;
-      bool ChangeResolution( int nDexVoxRatio) ;
+      int  GetPartMinDistFromPoint( const Point3d& ptP) const override ;
 
    public :                      // IGeoObjRW
       int GetNgeId( void) const override ;