diff --git a/EGkGeoConst.h b/EGkGeoConst.h
index 3e90033..ce11f4c 100644
--- a/EGkGeoConst.h
+++ b/EGkGeoConst.h
@@ -39,6 +39,11 @@ const double SIN_EPS_ANG_ZERO   = EPS_ANG_ZERO * DEGTORAD ;
 const double COS_ORTO_ANG_SMALL = SIN_EPS_ANG_SMALL ;
 const double COS_ORTO_ANG_ZERO  = SIN_EPS_ANG_ZERO ;
 
+// angoli notevoli (in gradi)
+const double ANG_RIGHT    = 90 ;
+const double ANG_STRAIGHT = 180 ;
+const double ANG_FULL     = 360 ;
+
 // altre costanti
 const double SQRT2   = 1.41421356237309504880 ;
 const double SQRT1_2 = 1 / SQRT2 ;
diff --git a/EGkPolyLine.h b/EGkPolyLine.h
index 9b17125..8a098d8 100644
--- a/EGkPolyLine.h
+++ b/EGkPolyLine.h
@@ -70,6 +70,8 @@ class PolyLine
       EGK_EXPORT bool GetNextLine( Point3d& ptIni, Point3d& ptFin) const
                         { return GetNextULine( nullptr, &ptIni, nullptr, &ptFin) ; }
       EGK_EXPORT bool IsPlanar( Plane3d& plPlane, double dToler = EPS_SMALL) const ;
+      EGK_EXPORT bool GetMaxDistanceFromLine( double& dMaxDist, const Point3d& ptAx,
+                                           const Vector3d& vtAx, double dLen, bool bIsSegment = true) const ;
 
    private :
       bool NewellPlane( Plane3d& plPlane) const ;
diff --git a/EgkSurfTriMesh.h b/EgkSurfTriMesh.h
index 6e19ed7..163dc65 100644
--- a/EgkSurfTriMesh.h
+++ b/EgkSurfTriMesh.h
@@ -33,6 +33,8 @@ class __declspec( novtable) ISurfTriMesh : public ISurf
       virtual bool AdjustTopology( void) = 0 ;
       virtual bool CreateByTriangulation( const PolyLine& PL) = 0 ;
       virtual bool CreateByExtrusion( const PolyLine& PL, const Vector3d& vtExtr) = 0 ;
+      virtual bool CreateByRevolution( const PolyLine& PL, const Point3d& ptAx, const Vector3d& vtAx,
+                                       double dAngRot, double dStepRot) = 0 ;
       virtual int GetVertexNum( void) const = 0 ;
       virtual int GetTriangleNum( void) const = 0 ;
       virtual int GetFirstVertex( Point3d& ptP) const = 0 ;