diff --git a/EgtGraphics.rc b/EgtGraphics.rc
index dfcacf1..cb70dab 100644
Binary files a/EgtGraphics.rc and b/EgtGraphics.rc differ
diff --git a/EgtGraphics.vcxproj b/EgtGraphics.vcxproj
index dd014fc..ebb7581 100644
--- a/EgtGraphics.vcxproj
+++ b/EgtGraphics.vcxproj
@@ -226,6 +226,7 @@ copy $(TargetPath) \EgtProg\Dll64</Command>
     <ClInclude Include="..\Include\EGrScene.h" />
     <ClInclude Include="DllMain.h" />
     <ClInclude Include="EGrUtils.h" />
+    <ClInclude Include="ObjMultiGraphics.h" />
     <ClInclude Include="SceExecutor.h" />
     <ClInclude Include="GraphObjs.h" />
     <ClInclude Include="ObjEGrGraphics.h" />
@@ -239,6 +240,7 @@ copy $(TargetPath) \EgtProg\Dll64</Command>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="EGrDllMain.cpp" />
+    <ClCompile Include="ObjMultiGraphics.cpp" />
     <ClCompile Include="SceExecutor.cpp" />
     <ClCompile Include="ObjNewGraphics.cpp" />
     <ClCompile Include="ObjOldGraphics.cpp" />
diff --git a/EgtGraphics.vcxproj.filters b/EgtGraphics.vcxproj.filters
index 0d7ccf9..47e21ec 100644
--- a/EgtGraphics.vcxproj.filters
+++ b/EgtGraphics.vcxproj.filters
@@ -81,6 +81,9 @@
     <ClInclude Include="TextureMgr.h">
       <Filter>File di intestazione</Filter>
     </ClInclude>
+    <ClInclude Include="ObjMultiGraphics.h">
+      <Filter>File di intestazione</Filter>
+    </ClInclude>
   </ItemGroup>
   <ItemGroup>
     <ClCompile Include="stdafx.cpp">
@@ -128,6 +131,9 @@
     <ClCompile Include="SceneTexture.cpp">
       <Filter>File di origine</Filter>
     </ClCompile>
+    <ClCompile Include="ObjMultiGraphics.cpp">
+      <Filter>File di origine</Filter>
+    </ClCompile>
   </ItemGroup>
   <ItemGroup>
     <ResourceCompile Include="EgtGraphics.rc">
diff --git a/ObjEGrGraphics.h b/ObjEGrGraphics.h
index 7309cc3..d95cf3c 100644
--- a/ObjEGrGraphics.h
+++ b/ObjEGrGraphics.h
@@ -31,6 +31,7 @@ class ObjEGrGraphics : public IObjGraphics
       virtual bool IsValid( void) = 0 ;
       virtual void SetScene( Scene* pScene) = 0 ;
       virtual Scene* GetScene( void) = 0 ;
+      virtual bool SetCurrent( int nCurr) { return false ; } ;
       virtual void Clear( void) = 0 ;
       virtual bool AddColor( const Color& colC) = 0 ;
       virtual bool AddMaterial( const Color& colAmb, const Color& colDiff,
diff --git a/ObjMultiGraphics.cpp b/ObjMultiGraphics.cpp
new file mode 100644
index 0000000..5a91a4e
--- /dev/null
+++ b/ObjMultiGraphics.cpp
@@ -0,0 +1,202 @@
+//----------------------------------------------------------------------------
+//  EgalTech 2017-2017
+//----------------------------------------------------------------------------
+// File : ObjMultiGraphics.cpp         Data : 02.02.17       Versione : 1.6x3
+// Contenuto : Implementazione classe multi-grafica di un oggetto geometrico.
+//
+//
+//
+// Modifiche : 02.02.17 DS Creazione modulo.
+//
+//
+//----------------------------------------------------------------------------
+
+//--------------------------- Include ----------------------------------------
+#include "stdafx.h"
+#include "ObjMultiGraphics.h"
+#include "ObjNewGraphics.h"
+#include "ObjOldGraphics.h"
+
+//----------------------------------------------------------------------------
+ObjMultiGraphics::~ObjMultiGraphics( void)
+{
+   for ( size_t i = 0 ; i < m_vOEGR.size() ; ++ i) {
+      delete m_vOEGR[i] ;
+      m_vOEGR[i] = nullptr ;
+   }
+}
+
+//----------------------------------------------------------------------------
+void
+ObjMultiGraphics::Reset( void)
+{
+   m_bValid = false ;
+   m_nCurr = - 1 ;
+}
+
+//----------------------------------------------------------------------------
+void
+ObjMultiGraphics::SetScene( Scene* pScene)
+{
+   m_pScene = pScene ;
+   for ( size_t i = 0 ; i < m_vOEGR.size() ; ++ i)
+      m_vOEGR[i]->SetScene( pScene) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::SetCurrent( int nCurr)
+{
+   if ( nCurr < 0  ||  nCurr >= int( m_vOEGR.size())) {
+      m_nCurr = - 1 ;
+      return false ;
+   }
+   m_nCurr = nCurr ;
+   return true ;
+}
+
+//----------------------------------------------------------------------------
+void
+ObjMultiGraphics::Clear( void)
+{
+   m_bValid = false ;
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return ;
+   m_vOEGR[m_nCurr]->Clear() ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddColor( const Color& colC)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   return m_vOEGR[m_nCurr]->AddColor( colC) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddMaterial( const Color& colAmb, const Color& colDiff,
+                               const Color& colSpec, float fShin)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   return m_vOEGR[m_nCurr]->AddMaterial( colAmb, colDiff, colSpec, fShin) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddBackMaterial( const Color& colAmbDiff)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   return m_vOEGR[m_nCurr]->AddBackMaterial( colAmbDiff) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddPoint( const Point3d& ptP, bool bAux)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   m_bValid = true ;
+   return m_vOEGR[m_nCurr]->AddPoint( ptP, bAux) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddLines( const PNTVECTOR& vPnt, bool bAux)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   m_bValid = true ;
+   return m_vOEGR[m_nCurr]->AddLines( vPnt, bAux) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddPolyLine( const PolyLine& PL, bool bAux)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   m_bValid = true ;
+   return m_vOEGR[m_nCurr]->AddPolyLine( PL, bAux) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::StartTriangles( int nNum, bool bAux)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   return m_vOEGR[m_nCurr]->StartTriangles( nNum, bAux) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   return m_vOEGR[m_nCurr]->AddTriangle( Tria, TFlags, TNrms) ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::EndTriangles( void)
+{
+   if ( m_nCurr < 0  ||  m_nCurr >= int( m_vOEGR.size()))
+      return false ;
+   m_bValid = true ;
+   return m_vOEGR[m_nCurr]->EndTriangles() ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux)
+{
+   bool bOk = true ;
+   for ( size_t i = 0 ; i < m_vOEGR.size() ; ++ i) {
+      if ( m_vOEGR[i] != nullptr  &&
+           m_vOEGR[i]->IsValid()  &&
+           ! m_vOEGR[i]->Draw( nStat, nMark, bSurfSha, nAlpha, bShowAux))
+         bOk = false ;
+   }
+   return bOk ;
+}
+
+//----------------------------------------------------------------------------
+bool
+ObjMultiGraphics::GetLocalBBox( BBox3d& b3Loc) const
+{
+  // svuoto BBox
+   m_b3Loc.Reset() ;
+  // aggiorno il bbox con quello dei componenti
+   for ( size_t i = 0 ; i < m_vOEGR.size() ; ++ i) {
+      if ( m_vOEGR[i] != nullptr  &&
+           m_vOEGR[i]->IsValid()) {
+         BBox3d b3Temp ;
+         if ( m_vOEGR[i]->GetLocalBBox( b3Temp))
+            m_b3Loc.Add( b3Temp) ;
+      }
+   }
+  // copio
+   b3Loc = m_b3Loc ;
+  // verifico non sia vuoto
+   return ! m_b3Loc.IsEmpty() ;
+}
+
+//----------------------------------------------------------------------------
+ObjMultiGraphics::ObjMultiGraphics( int nCount, bool bNewWay)
+{
+   m_pScene = nullptr ;
+   m_bValid = false ;
+   m_vOEGR.reserve( nCount) ;
+   for ( int i = 0 ; i < nCount ; ++ i) {
+      if ( bNewWay)
+         m_vOEGR.emplace_back( new ObjNewGraphics) ;
+      else
+         m_vOEGR.emplace_back( new ObjOldGraphics) ;
+   }
+   m_nCurr = - 1 ;
+}
diff --git a/ObjMultiGraphics.h b/ObjMultiGraphics.h
new file mode 100644
index 0000000..f907b34
--- /dev/null
+++ b/ObjMultiGraphics.h
@@ -0,0 +1,56 @@
+//----------------------------------------------------------------------------
+//  EgalTech 2017-2017
+//----------------------------------------------------------------------------
+// File : ObjMultiGraphics.h           Data : 02.02.17       Versione : 1.6x3
+// Contenuto : Dichiarazione classe multi-grafica di un oggetto geometrico.
+//
+//
+//
+// Modifiche : 02.02.17 DS Creazione modulo.
+//
+//
+//----------------------------------------------------------------------------
+
+#pragma once
+
+#include "ObjEGrGraphics.h"
+#include <vector>
+
+//----------------------------------------------------------------------------
+class ObjMultiGraphics : public ObjEGrGraphics
+{
+   public :             // IObjGraphics
+      ~ObjMultiGraphics( void) override ;
+      void Reset( void) override ;
+
+   public :             // ObjEGrGraphics
+      bool IsValid( void) override
+              { return m_bValid ; }
+      void SetScene( Scene* pScene) override ;
+      Scene* GetScene( void) override
+              { return m_pScene ; }
+      bool SetCurrent( int nCurr)  ;
+      void Clear( void) override ;
+      bool AddColor( const Color& colC) override ;
+      bool AddMaterial( const Color& colAmb, const Color& colDiff,
+                        const Color& colSpec, float fShin) override ;
+      bool AddBackMaterial( const Color& colAmbDiff) override ;
+      bool AddPoint( const Point3d& ptP, bool bAux = false) override ;
+      bool AddLines( const PNTVECTOR& vPnt, bool bAux = false) override ;
+      bool AddPolyLine( const PolyLine& PL, bool bAux = false) override ;
+      bool StartTriangles( int nNum, bool bAux = false) override ;
+      bool AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms) override ;
+      bool EndTriangles( void) override ;
+      bool Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux) override ;
+      bool GetLocalBBox( BBox3d& b3Loc) const override ;
+
+   public :
+      ObjMultiGraphics( int nCount, bool bNewWay) ;
+
+   private :
+      Scene*  m_pScene ;                      // puntatore alla scena
+      bool    m_bValid ;                      // flag
+      mutable BBox3d  m_b3Loc ;               // BoundingBox locale
+      int     m_nCurr ;                       // Graphics corrente
+      std::vector<ObjEGrGraphics*> m_vOEGR ;  // vettore di Graphics
+} ;
diff --git a/ObjNewGraphics.h b/ObjNewGraphics.h
index 10e0bc5..aba3ee9 100644
--- a/ObjNewGraphics.h
+++ b/ObjNewGraphics.h
@@ -55,30 +55,30 @@ typedef std::list<NgAtom>    NGALIST ;
 class ObjNewGraphics : public ObjEGrGraphics
 {
    public :             // IObjGraphics
-      virtual ~ObjNewGraphics( void) ;
-      virtual void Reset( void) ;
+      ~ObjNewGraphics( void) override ;
+      void Reset( void) override ;
 
    public :             // ObjEGrGraphics
-      virtual bool IsValid( void)
-                      { return m_bValid ; }
-      virtual void SetScene( Scene* pScene)
-                      { m_pScene = pScene ; }
-      virtual Scene* GetScene( void)
-                      { return m_pScene ; }
-      virtual void Clear( void) ;
-      virtual bool AddColor( const Color& colC) ;
-      virtual bool AddMaterial( const Color& colAmb, const Color& colDiff,
-                                const Color& colSpec, float fShin) ;
-      virtual bool AddBackMaterial( const Color& colAmbDiff) ;
-      virtual bool AddPoint( const Point3d& ptP, bool bAux = false) ;
-      virtual bool AddLines( const PNTVECTOR& vPnt, bool bAux = false) ;
-      virtual bool AddPolyLine( const PolyLine& PL, bool bAux = false) ;
-      virtual bool StartTriangles( int nNum, bool bAux = false) ;
-      virtual bool AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms) ;
-      virtual bool EndTriangles( void) ;
-      virtual bool Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux) ;
-      virtual bool GetLocalBBox( BBox3d& b3Loc) const
-                      { b3Loc = m_b3Loc ; return ! m_b3Loc.IsEmpty() ; }
+      bool IsValid( void) override
+              { return m_bValid ; }
+      void SetScene( Scene* pScene) override
+              { m_pScene = pScene ; }
+      Scene* GetScene( void) override
+              { return m_pScene ; }
+      void Clear( void) override ;
+      bool AddColor( const Color& colC) override ;
+      bool AddMaterial( const Color& colAmb, const Color& colDiff,
+                        const Color& colSpec, float fShin) override ;
+      bool AddBackMaterial( const Color& colAmbDiff) override ;
+      bool AddPoint( const Point3d& ptP, bool bAux = false) override ;
+      bool AddLines( const PNTVECTOR& vPnt, bool bAux = false) override ;
+      bool AddPolyLine( const PolyLine& PL, bool bAux = false) override ;
+      bool StartTriangles( int nNum, bool bAux = false) override ;
+      bool AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms) override ;
+      bool EndTriangles( void) override ;
+      bool Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux) override ;
+      bool GetLocalBBox( BBox3d& b3Loc) const override
+              { b3Loc = m_b3Loc ; return ! m_b3Loc.IsEmpty() ; }
 
    public :
       ObjNewGraphics( void) : m_pScene( nullptr), m_bValid( false) {}
diff --git a/ObjOldGraphics.h b/ObjOldGraphics.h
index 7d2241d..74949bc 100644
--- a/ObjOldGraphics.h
+++ b/ObjOldGraphics.h
@@ -60,30 +60,30 @@ typedef std::vector<OgAtom>   OGAVECT ;
 class ObjOldGraphics : public ObjEGrGraphics
 {
    public :             // IObjGraphics
-      virtual ~ObjOldGraphics( void) ;
-      virtual void Reset( void) ;
+      ~ObjOldGraphics( void) override ;
+      void Reset( void) override ;
 
    public :             // ObjEGrGraphics
-      virtual bool IsValid( void)
-                      { return m_bValid ; }
-      virtual void SetScene( Scene* pScene)
-                      { m_pScene = pScene ; }
-      virtual Scene* GetScene( void)
-                      { return m_pScene ; }
-      virtual void Clear( void) ;
-      virtual bool AddColor( const Color& colC) ;
-      virtual bool AddMaterial( const Color& colAmb, const Color& colDiff,
-                                const Color& colSpec, float fShin) ;
-      virtual bool AddBackMaterial( const Color& colAmbDiff) ;
-      virtual bool AddPoint( const Point3d& ptP, bool bAux = false) ;
-      virtual bool AddLines( const PNTVECTOR& vPnt, bool bAux = false) ;
-      virtual bool AddPolyLine( const PolyLine& PL, bool bAux = false) ;
-      virtual bool StartTriangles( int nNum, bool bAux = false) ;
-      virtual bool AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms) ;
-      virtual bool EndTriangles( void) ;
-      virtual bool Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux) ;
-      virtual bool GetLocalBBox( BBox3d& b3Loc) const
-                      { b3Loc = m_b3Loc ; return ! m_b3Loc.IsEmpty() ; }
+      bool IsValid( void) override
+              { return m_bValid ; }
+      void SetScene( Scene* pScene) override
+              { m_pScene = pScene ; }
+      Scene* GetScene( void) override
+              { return m_pScene ; }
+      void Clear( void) override ;
+      bool AddColor( const Color& colC) override ;
+      bool AddMaterial( const Color& colAmb, const Color& colDiff,
+                        const Color& colSpec, float fShin) override ;
+      bool AddBackMaterial( const Color& colAmbDiff) override ;
+      bool AddPoint( const Point3d& ptP, bool bAux = false) override ;
+      bool AddLines( const PNTVECTOR& vPnt, bool bAux = false) override ;
+      bool AddPolyLine( const PolyLine& PL, bool bAux = false) override ;
+      bool StartTriangles( int nNum, bool bAux = false) override ;
+      bool AddTriangle( const Triangle3d& Tria, const TriFlags3d& TFlags, const TriNormals3d& TNrms) override ;
+      bool EndTriangles( void) override ;
+      bool Draw( int nStat, int nMark, bool bSurfSha, int nAlpha, bool bShowAux) override ;
+      bool GetLocalBBox( BBox3d& b3Loc) const override
+              { b3Loc = m_b3Loc ; return ! m_b3Loc.IsEmpty() ; }
 
    public :
       ObjOldGraphics( void) : m_pScene( nullptr), m_nCurrMode( GL_NONE), m_bValid( false) {}
diff --git a/SceneGeom.cpp b/SceneGeom.cpp
index b4f154b..39b09f3 100644
--- a/SceneGeom.cpp
+++ b/SceneGeom.cpp
@@ -16,7 +16,9 @@
 #include "Scene.h"
 #include "ObjOldGraphics.h"
 #include "ObjNewGraphics.h"
+#include "ObjMultiGraphics.h"
 #include "EGrUtils.h"
+#include "DllMain.h"
 #include "/EgtDev/Include/EgtILogger.h"
 #include "/EgtDev/Include/EGnStringUtils.h"
 #include "/EgtDev/Include/EGkFrame3d.h"
@@ -35,7 +37,7 @@
 using namespace std ;
 
 //------------------------------ Local functions -----------------------------
-static ObjEGrGraphics* CreateObjEGrGraphics( bool bNewWay) ;
+static ObjEGrGraphics* CreateObjEGrGraphics( int nCount, bool bNewWay) ;
 static bool CalcCurveTailMark( const Vector3d& vtRef, const PolyLine& plCrv, PolyLine& plMark) ;
 static bool CalcCurveTipArrow( const Vector3d& vtRef, const PolyLine& plCrv, PolyLine& plArr) ;
 static bool CalcConnectingLines( const PolyLine& plCrv, const Vector3d& vtTh, bool bDense, PNTVECTOR& vPnt) ;
@@ -171,7 +173,18 @@ Scene::DrawGeoObj( const IGdbIterator& iIter, int nPass, const MdStMkCol& siObj)
 
   // se non esiste grafica associata, la creo
    if ( pGeoObj->GetObjGraphics() == nullptr) {
-     // nuova modalità grafica solo per superfici con molti triangoli
+     // oggetto grafico molteplice solo per Zmap che lo richiedono
+      int nCount = 0 ;
+      if ( nGeoType == VOL_ZMAP) {
+         const IVolZmap* pZmap = GetVolZmap( pGeoObj) ;
+         if ( pZmap != nullptr) {
+            switch ( m_nShowZmap) {
+            case ZSM_SURF : nCount = pZmap->GetBlockCount() ; break ;
+            case ZSM_BOTH : nCount = pZmap->GetBlockCount() + 1 ; break ;
+            }
+         }
+      }
+     // nuova modalità grafica solo per superfici con molti triangoli o solidi Zmap
       const int N_MIN_TRIA_NEWWAY = 100 ; 
       bool bNewWay = false ;
       if ( m_bNewWay) {
@@ -188,7 +201,7 @@ Scene::DrawGeoObj( const IGdbIterator& iIter, int nPass, const MdStMkCol& siObj)
             bNewWay = true ;
          }
       }  
-      ObjEGrGraphics* pGraphics = CreateObjEGrGraphics( bNewWay) ;
+      ObjEGrGraphics* pGraphics = CreateObjEGrGraphics( nCount, bNewWay) ;
       if ( pGraphics == nullptr)
          return false ;
       pGraphics->SetScene( this) ;
@@ -329,36 +342,52 @@ Scene::DrawGeoObj( const IGdbIterator& iIter, int nPass, const MdStMkCol& siObj)
          const IVolZmap* pZmap = GetVolZmap( pGeoObj) ;
          if ( pZmap == nullptr)
             return false ;
-         // recupero il materiale
+        // recupero il materiale
          Material mMat ;
          if ( ! iIter.GetCalcMaterial( mMat))
             mMat.Set( m_colDef) ;
-        // impostazioni iniziali
-         pGraphics->Clear() ;
-        // visualizzazione superficie
-         if ( m_nShowZmap != ZSM_LINES) {
-            pGraphics->AddColor( siObj.colObj) ;  // per wireframe
-            pGraphics->AddMaterial( mMat.GetAmbient(), mMat.GetDiffuse(),
-                                    mMat.GetSpecular(), mMat.GetShininess()) ;
-            pGraphics->AddBackMaterial( GetSurfBackColor( mMat.GetDiffuse())) ;
-           // recupero la geometria
-            TRIA3DLIST lstTria ;
-            pZmap->GetAllTriangles( lstTria) ;
-           // passo i triangoli alla grafica
-            pGraphics->StartTriangles( int( lstTria.size())) ;
-            for ( const auto& Tria : lstTria) {
-               TriFlags3d TFlags ;
-               TriNormals3d TNrms ;
-               for ( int i = 0 ; i < 3 ; ++i) {
-                  TFlags.bFlag[i] = true ;
-                  TNrms.vtN[i] = Tria.GetN() ;
-               }
-               pGraphics->AddTriangle( Tria, TFlags, TNrms) ;
-            }    
-            pGraphics->EndTriangles() ;
+        // ciclo sui blocchi da aggiornare
+         std::vector<bool> vUpdate ;
+         pZmap->GetBlockInfo( vUpdate) ;
+         int nCount = int( vUpdate.size()) ;
+         for ( int i = 0 ; i < nCount ; ++ i) {
+           // se da non aggiornare, vado oltre
+            if ( ! vUpdate[i])
+               continue ;
+           // imposto indice blocco corrente
+            pGraphics->SetCurrent( i) ;
+           // lo pulisco
+            pGraphics->Clear() ;
+           // visualizzazione superficie
+            if ( m_nShowZmap != ZSM_LINES) {
+               pGraphics->AddColor( siObj.colObj) ;  // per wireframe
+               pGraphics->AddMaterial( mMat.GetAmbient(), mMat.GetDiffuse(),
+                                       mMat.GetSpecular(), mMat.GetShininess()) ;
+               pGraphics->AddBackMaterial( GetSurfBackColor( mMat.GetDiffuse())) ;
+              // recupero la geometria
+               TRIA3DLIST lstTria ;
+               pZmap->GetBlockTriangles( i, lstTria) ;
+              // passo i triangoli alla grafica
+               pGraphics->StartTriangles( int( lstTria.size())) ;
+               for ( const auto& Tria : lstTria) {
+                  TriFlags3d TFlags ;
+                  TriNormals3d TNrms ;
+                  for ( int j = 0 ; j < 3 ; ++ j) {
+                     TFlags.bFlag[j] = true ;
+                     TNrms.vtN[j] = Tria.GetN() ;
+                  }
+                  pGraphics->AddTriangle( Tria, TFlags, TNrms) ;
+               }    
+               pGraphics->EndTriangles() ;
+            }
          }
-        // visualizzazione spilloni
+        // visualizzazione spilloni (sempre nell'ultimo blocco)
          if ( m_nShowZmap == ZSM_LINES  ||  m_nShowZmap == ZSM_BOTH) {
+           // imposto indice blocco corrente
+            pGraphics->SetCurrent( nCount) ;
+           // lo pulisco
+            pGraphics->Clear() ;
+           // ciclo sui tre gruppi di spilloni
             Color vCol[3] = {BLUE, RED, GREEN} ;
             for ( int k = 0 ; k < 3 ; ++ k) {
                pGraphics->AddColor( vCol[k]) ;
@@ -578,9 +607,11 @@ Scene::DeleteObjGraphicsGroup( int nId)
 //------------------------------ Local functions -----------------------------
 //----------------------------------------------------------------------------
 static ObjEGrGraphics*
-CreateObjEGrGraphics( bool bNewWay)
+CreateObjEGrGraphics( int nCount, bool bNewWay)
 {
-   if ( bNewWay)
+   if ( nCount > 1)
+      return ( new ObjMultiGraphics( nCount, bNewWay)) ;
+   else if ( bNewWay)
       return ( new ObjNewGraphics) ;
    else
       return ( new ObjOldGraphics) ;