diff --git a/SceneGeom.cpp b/SceneGeom.cpp
index 85de992..ad12d2e 100644
--- a/SceneGeom.cpp
+++ b/SceneGeom.cpp
@@ -581,6 +581,7 @@ Scene::DrawGeoObj( const IGdbIterator& iIter, int nPass, const MdStMkCol& siObj)
                   pGraphics->SetCounter( pZmap->GetBlockUpdatingCounter( i)) ;
                }
             }
+            pGraphics->Validate() ;
          }
         // visualizzazione spilloni e normali (sempre nell'ultimo blocco)
          bool bLinNrmShow = ( ( m_nShowZmap & ZSM_LINES) != 0  ||  ( m_nShowZmap & ZSM_NORMALS) != 0) ;