diff --git a/EGkSurfBezier.h b/EGkSurfBezier.h
index d53d306..6ebf797 100644
--- a/EGkSurfBezier.h
+++ b/EGkSurfBezier.h
@@ -37,6 +37,7 @@ class __declspec( novtable) ISurfBezier : public ISurf
       virtual bool SetControlPoint( int nIndU, int nIndV, const Point3d& ptCtrl, double dW) = 0 ;
       virtual bool SetControlPoint( int nInd, const Point3d& ptCtrl, double dW) = 0 ;
       virtual bool SetTrimRegion( const ISurfFlatRegion& sfrTrimReg) = 0 ;
+      virtual ISurfFlatRegion* GetTrimRegion( void) const = 0 ;
       virtual bool GetInfo( int& nDegU, int& nDegV, int& nSpanU, int& nSpanV, bool& bIsRat, bool& bTrimmed) const = 0 ;
       virtual const Point3d& GetControlPoint( int nIndU, int nIndV, bool* pbOk) const = 0 ;
       virtual const Point3d& GetControlPoint( int nInd, bool* pbOk) const = 0 ;
@@ -57,6 +58,7 @@ class __declspec( novtable) ISurfBezier : public ISurf
       virtual bool GetControlCurveOnU( int nIndV, PolyLine& plCtrlU) const = 0 ;
       virtual bool GetControlCurveOnV( int nIndU, PolyLine& plCtrlV) const = 0 ;
       virtual const ISurfTriMesh* GetAuxSurf( void) const = 0 ;
+      virtual bool GetLeaves ( std::vector<std::tuple<int, Point3d, Point3d>>& vLeaves) const = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------