diff --git a/vcg/space/segment3.h b/vcg/space/segment3.h
index d22c6e78..57f258a0 100644
--- a/vcg/space/segment3.h
+++ b/vcg/space/segment3.h
@@ -112,10 +112,12 @@ public:
 	{ return _p0 + (_p1 - _p0) * t; }
 	  /// return the middle point
 	inline PointType MidPoint( ) const
-  { return ( _p0 + _p1) / ScalarType(2.0) ; }
-  inline PointType Direction( ) const
-  { return ( _p1 - _p0) ; }
-    /// return the bounding box
+	{ return ( _p0 + _p1) / ScalarType(2.0) ; }
+	inline PointType Direction( ) const
+	{ return ( _p1 - _p0) ; }
+	inline PointType NormalizedDirection( ) const
+	{ return ( _p1 - _p0).Normalize() ; }
+	/// return the bounding box
 	inline Box3<ScalarType> BBox( ) const
 	{ Box3<ScalarType> t; 
 	  if (_p0[0]<_p1[0]) { t.min[0]=_p0[0];t.max[0]=_p1[0];} else { t.min[0]=_p1[0];t.max[0]=_p0[0];}