diff --git a/EGkSurfTriMesh.h b/EGkSurfTriMesh.h
index 18bc12b..8a1dccc 100644
--- a/EGkSurfTriMesh.h
+++ b/EGkSurfTriMesh.h
@@ -86,6 +86,9 @@ class __declspec( novtable) ISurfTriMesh : public ISurf
       virtual bool Cut( const Plane3d& plPlane, bool bSaveOnEq) = 0 ;
       virtual bool GetAllTriaOverlapBox( const BBox3d& b3Box, INTVECTOR& vT) const = 0 ;
       virtual const BBox3d& GetAllTriaBox( void) const = 0 ;
+      virtual int GetPartCount( void) const = 0 ;
+      virtual bool RemovePart( int nPart) = 0 ;
+      virtual ISurfTriMesh* ClonePart( int nPart) const = 0 ;
 } ;
 
 //-----------------------------------------------------------------------------