bool ok = true;
double u0 = GetNodeU( TopoDS::Edge( E ), nn[0], nn[1], &ok );
double u1 = GetNodeU( TopoDS::Edge( E ), nn[1], nn[0], &ok );
bool ok = true;
double u0 = GetNodeU( TopoDS::Edge( E ), nn[0], nn[1], &ok );
double u1 = GetNodeU( TopoDS::Edge( E ), nn[1], nn[0], &ok );