void SMESHDS_GroupOnGeom::SetShape( const TopoDS_Shape& theShape)
{
  SMESHDS_Mesh* aMesh = const_cast<SMESHDS_Mesh*>( GetMesh() );
  mySubMesh = aMesh->MeshElements( aMesh->AddCompoundSubmesh( theShape ));
  myShape   = theShape;
}