diff --git a/EgtExchange.rc b/EgtExchange.rc
index 464971a..8165de4 100644
Binary files a/EgtExchange.rc and b/EgtExchange.rc differ
diff --git a/ExcExecutor.cpp b/ExcExecutor.cpp
index 50eb92d..a37807b 100644
--- a/ExcExecutor.cpp
+++ b/ExcExecutor.cpp
@@ -82,8 +82,8 @@ ExcExecutor::SetGeomDB( IGeomDB* pGdb)
 bool
 ExcExecutor::ExecuteImportStl( const string& sCmd2, const STRVECTOR& vsParams) 
 {
-  // 2 parametri : nome del file e Id del gruppo
-   if ( vsParams.size() != 2)
+  // 2 o 3 parametri : nome del file, Id del gruppo[, ScaleFactor]
+   if ( vsParams.size() != 2  &&  vsParams.size() != 3)
       return false ;
   // eventuale conversione di token nel nome file
    string sFile = vsParams[0] ;
@@ -92,6 +92,10 @@ ExcExecutor::ExecuteImportStl( const string& sCmd2, const STRVECTOR& vsParams)
    int nId = m_pParser->GetIdParam( vsParams[1]) ;
    if ( nId == CMD_ID_ERROR)
       return false ;
+  // gestisco ScaleFactor
+   double dScaleFactor = 1 ;
+   if ( vsParams.size() >= 3)
+      FromString( vsParams[2], dScaleFactor) ;
 
   // preparo l'importatore
    IImportStl* pImpStl = CreateImportStl() ;
@@ -100,7 +104,7 @@ ExcExecutor::ExecuteImportStl( const string& sCmd2, const STRVECTOR& vsParams)
       return false ;
    }
   // eseguo l'importazione
-   bool bOk = pImpStl->Import( sFile, m_pGDB, nId) ;
+   bool bOk = pImpStl->Import( sFile, m_pGDB, nId, dScaleFactor) ;
   // cancello l'importatore
    delete pImpStl ;
 
diff --git a/ImportStl.cpp b/ImportStl.cpp
index 10934f8..45167cc 100644
--- a/ImportStl.cpp
+++ b/ImportStl.cpp
@@ -19,11 +19,15 @@
 #include "/EgtDEv/Include/EGnScan.h"
 #include "/EgtDev/Include/EgnStringUtils.h"
 #include "/EgtDev/Include/EgnStringConverter.h"
+#include "/EgtDev/Include/EGkPointGrid3d.h"
 #include "/EgtDev/Include/EGkGeomDB.h"
 #include "/EgtDev/Include/EGkSurfTriMesh.h"
 
 using namespace std ;
 
+//----------------------------------------------------------------------------
+static const int    GRID_NUM_BUCKETS = 50000 ;
+
 //----------------------------------------------------------------------------
 IImportStl*
 CreateImportStl( void)
@@ -33,13 +37,35 @@ CreateImportStl( void)
 
 //----------------------------------------------------------------------------
 bool
-ImportStl::Import( const string& sFile, IGeomDB* pGDB, int nIdGroup)
+ImportStl::Import( const string& sFile, IGeomDB* pGDB, int nIdGroup, double dScaleFactor)
 {
+  // verifico il DB geometrico
+   if ( pGDB == nullptr) {
+      LOG_ERROR( GetEExLogger(), "ImportStl : Error on GeomDB")
+      return false ;
+   }
+   m_pGDB = pGDB ;
+
+  // verifico l'Id di gruppo
+   if ( ! m_pGDB->ExistsObj( nIdGroup)) {
+      LOG_ERROR( GetEExLogger(), "ImportStl : Error on IdGroup")
+      return false ;
+   }
+   m_nIdGroup = nIdGroup ;
+
+  // verifico il fattore di scala
+   if ( dScaleFactor < EPS_SMALL) {
+      LOG_ERROR( GetEExLogger(), "ImportStl : Error on ScaleFactor too small (minimum 0.001).")
+      return false ;
+   }
+   m_dScaleFactor = dScaleFactor ;
+
+  // eseguo l'opportuna importazione
    switch ( StlType( sFile)) {
    case STL_ASCII :
-      return ImportASCII( sFile, pGDB, nIdGroup) ;
+      return ImportASCII( sFile) ;
    case STL_BINARY :
-      return ImportBinary( sFile, pGDB, nIdGroup) ;
+      return ImportBinary( sFile) ;
    default :
       return false ;
    }
@@ -78,7 +104,7 @@ ImportStl::StlType( const std::string& sFile)
 
 //----------------------------------------------------------------------------
 bool
-ImportStl::ImportASCII( const string& sFile, IGeomDB* pGDB, int nIdGroup)
+ImportStl::ImportASCII( const string& sFile)
 {
   // inizializzo lo scanner
    Scanner TheScanner ;
@@ -87,20 +113,6 @@ ImportStl::ImportASCII( const string& sFile, IGeomDB* pGDB, int nIdGroup)
       return false ;
    }
 
-  // verifico il DB geometrico
-   if ( pGDB == nullptr) {
-      LOG_ERROR( GetEExLogger(), "ImportStl : Error on GeomDB")
-      return false ;
-   }
-   m_pGDB = pGDB ;
-
-  // verifico l'Id di gruppo
-   if ( ! m_pGDB->ExistsObj( nIdGroup)) {
-      LOG_ERROR( GetEExLogger(), "ImportStl : Error on IdGroup")
-      return false ;
-   }
-   m_nIdGroup = nIdGroup ;
-
   // ciclo di lettura degli oggetti
    bool bOk = true ;
    bool bEnd = false ;
@@ -151,15 +163,15 @@ ImportStl::LoadSolid( Scanner& TheScanner, bool& bEnd)
       return false ;
    }
 
-  // Map dei vertici ( lexicographic -> usare epsilon piccoli)
-   CmpPnt    comp( EPS_SMALL) ;
-   PntIntMap MapVert( comp) ; 
+  // Grid dei vertici
+   PointGrid3d VertGrid ;
+   VertGrid.Init( GRID_NUM_BUCKETS) ;
 
   // ciclo di lettura dei triangoli
    bool bOk = true ;
    bool bTEnd = false ;
    do {
-      if ( ! LoadTriangle( TheScanner, Get( pSTM), MapVert, bTEnd)) {
+      if ( ! LoadTriangle( TheScanner, Get( pSTM), VertGrid, bTEnd)) {
          bOk = false ;
          string sOut = "ImportStl : Error on line " + ToString( TheScanner.GetCurrLineNbr()) ;
          LOG_ERROR( GetEExLogger(), sOut.c_str())
@@ -195,7 +207,7 @@ ImportStl::LoadSolid( Scanner& TheScanner, bool& bEnd)
 
 //----------------------------------------------------------------------------
 bool
-ImportStl::LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PntIntMap& MapVert, bool& bEnd)
+ImportStl::LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PointGrid3d& VertGrid, bool& bEnd)
 {
    string sLine ;
    STRVECTOR vsParams ;
@@ -230,7 +242,6 @@ ImportStl::LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PntIntMap& Map
 
   // ciclo sui tre vertici
    int nIdV[3] ;
-   PntIntMap::iterator Iter ;
    for ( int i = 0 ; i < 3 ; ++ i) {
      // recupero una linea
       if ( ! TheScanner.GetLine( sLine))
@@ -249,16 +260,18 @@ ImportStl::LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PntIntMap& Map
            ! FromString( vsParams[2], ptP.y)  ||
            ! FromString( vsParams[3], ptP.z))
          return false ;
+     // scalo il vertice
+      ptP *= m_dScaleFactor ;
      // verifico se vertice già presente
-      Iter = MapVert.find( ptP) ;
-      if ( Iter == MapVert.end()) {
+      int nId ;
+      if ( ! VertGrid.Find( ptP, 2 * EPS_SMALL, nId)) {
         // aggiungo il vertice
          if ( ( nIdV[i] = pSTM->AddVertex( ptP)) == SVT_NULL)
             return false ;
-         MapVert[ptP] = nIdV[i] ;
+         VertGrid.InsertPoint( ptP, nIdV[i]) ;
       }
       else
-         nIdV[i] = Iter->second ;
+         nIdV[i] = nId ;
    }
 
   // se i vertici sono tutti diversi tra loro, inserisco il triangolo
@@ -297,7 +310,7 @@ ImportStl::LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PntIntMap& Map
 
 //----------------------------------------------------------------------------
 bool
-ImportStl::ImportBinary( const string& sFile, IGeomDB* pGDB, int nIdGroup)
+ImportStl::ImportBinary( const string& sFile)
 {
   // apertura del file di ingresso
    ifstream InFile ;
@@ -305,20 +318,6 @@ ImportStl::ImportBinary( const string& sFile, IGeomDB* pGDB, int nIdGroup)
    if ( InFile.fail())
       return false ;
 
-  // verifico il DB geometrico
-   if ( pGDB == nullptr) {
-      LOG_ERROR( GetEExLogger(), "ImportStl : Error on GeomDB")
-      return false ;
-   }
-   m_pGDB = pGDB ;
-
-  // verifico l'Id di gruppo
-   if ( ! m_pGDB->ExistsObj( nIdGroup)) {
-      LOG_ERROR( GetEExLogger(), "ImportStl : Error on IdGroup")
-      return false ;
-   }
-   m_nIdGroup = nIdGroup ;
-
   // lettura dei primi ottanta byte (commento da scartare)
    const int LEN_REM = 80 ;
    char cRem[LEN_REM] ;
@@ -344,9 +343,9 @@ ImportStl::ImportBinary( const string& sFile, IGeomDB* pGDB, int nIdGroup)
       return false ;
    }
 
-  // Map dei vertici ( lexicographic -> usare epsilon piccoli)
-   CmpPnt    comp( EPS_SMALL) ;
-   PntIntMap MapVert( comp) ; 
+  // Grid dei vertici
+   PointGrid3d VertGrid ;
+   VertGrid.Init( GRID_NUM_BUCKETS) ;
 
   // lettura dei triangoli
    for ( int j = 0 ; j < uTria.i ; ++ j) {
@@ -358,7 +357,6 @@ ImportStl::ImportBinary( const string& sFile, IGeomDB* pGDB, int nIdGroup)
          return false ;
      // ciclo sui tre vertici
       int nIdV[3] ;
-      PntIntMap::iterator Iter ;
       for ( int i = 0 ; i < 3 ; ++ i) {
          const int LEN_3F = 12 ;
          union { float f[3]; char c[LEN_3F]; } ufP ;
@@ -366,16 +364,18 @@ ImportStl::ImportBinary( const string& sFile, IGeomDB* pGDB, int nIdGroup)
          if ( InFile.gcount() != LEN_3F)
             return false ;
          Point3d ptP( ufP.f[0], ufP.f[1], ufP.f[2]) ;
+        // scalo il vertice
+         ptP *= m_dScaleFactor ;
         // verifico se vertice già presente
-         Iter = MapVert.find( ptP) ;
-         if ( Iter == MapVert.end()) {
+         int nId ;
+         if ( ! VertGrid.Find( ptP, 2 * EPS_SMALL, nId)) {
            // aggiungo il vertice
             if ( ( nIdV[i] = pSTM->AddVertex( ptP)) == SVT_NULL)
                return false ;
-            MapVert[ptP] = nIdV[i] ;
+            VertGrid.InsertPoint( ptP, nIdV[i]) ;
          }
          else
-            nIdV[i] = Iter->second ;
+            nIdV[i] = nId ;
       }
 
      // se i vertici sono tutti diversi tra loro, inserisco il triangolo
diff --git a/ImportStl.h b/ImportStl.h
index b347f33..b637c77 100644
--- a/ImportStl.h
+++ b/ImportStl.h
@@ -1,7 +1,7 @@
 //----------------------------------------------------------------------------
 //  EgalTech 2014-2014
 //----------------------------------------------------------------------------
-// File : ImportStl.h           Data : 04.04.14          Versione : 1.5d1
+// File : ImportStl.h           Data : 16.05.14          Versione : 1.5e3
 // Contenuto : Dichiarazione della classe ImportStl.
 //
 //
@@ -15,10 +15,10 @@
 
 #include "/EgtDev/Include/EExImportStl.h"
 #include "/EgtDev/Include/EgkPoint3d.h"
-#include <map>
 
 class Scanner ;
 class ISurfTriMesh ;
+class PointGrid3d ;
 
 //----------------------------------------------------------------------------
 
@@ -26,37 +26,14 @@ class ISurfTriMesh ;
 class ImportStl : public IImportStl
 {
    public :
-      virtual bool Import( const std::string& sFile, IGeomDB* pGDB, int nIdGroup) ;
-
-   private :
-      class CmpPnt
-      {
-         public :
-           CmpPnt( double dEps = EPS_SMALL) : m_dEps( dEps)
-              {}
-           bool operator()( const Point3d& ptP0, const Point3d& ptP1) const
-              {
-                if ( fabs( ptP0.x - ptP1.x) <= m_dEps) {
-                   if ( fabs( ptP0.y - ptP1.y) <= m_dEps) {
-                      return ( ptP0.z < ptP1.z - m_dEps) ;
-                   }
-                   else
-                      return ( ptP0.y < ptP1.y - m_dEps) ;
-                }
-                else
-                   return ( ptP0.x < ptP1.x - m_dEps) ;
-              }
-         private :
-           double m_dEps ;
-      } ;
-      typedef std::map< Point3d, int, CmpPnt> PntIntMap ;
+      virtual bool Import( const std::string& sFile, IGeomDB* pGDB, int nIdGroup, double dScaleFactor = 1) ;
 
    private :
       int  StlType( const std::string& sFile) ;
-      bool ImportASCII( const std::string& sFile, IGeomDB* pGDB, int nIdGroup) ;
+      bool ImportASCII( const std::string& sFile) ;
       bool LoadSolid( Scanner& TheScanner, bool& bEnd) ;
-      bool LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PntIntMap& MapVert, bool& bEnd) ;
-      bool ImportBinary( const std::string& sFile, IGeomDB* pGDB, int nIdGroup) ;
+      bool LoadTriangle( Scanner& TheScanner, ISurfTriMesh* pSTM, PointGrid3d& VertGrid, bool& bEnd) ;
+      bool ImportBinary( const std::string& sFile) ;
 
    private :
       enum { STL_ERROR = 0, STL_ASCII = 1, STL_BINARY = 2 } ;
@@ -64,4 +41,5 @@ class ImportStl : public IImportStl
    private :
       IGeomDB*  m_pGDB ;
       int       m_nIdGroup ;
+      double    m_dScaleFactor ;
 } ;