.

                //

                int t = get_t(tp1_3d, tp2_3d, tp3_3d);

                std::array<Vector2, 3> tps_2d = {{to_2d(tp1_3d, t), to_2d(tp2_3d, t), to_2d(tp3_3d, t)}};

                std::array<Vector2, 4> cs = {{(tps_2d[0] + tps_2d[1] + tps_2d[2]) / 3}};

                for (int k = 0; k < 3; k++)

                    cs[k + 1] = (tps_2d[k] + cs[0]) / 3;

                std::array<Vector2, 3> ps_2d;

                bool is_all_out = true;

                for (int f_id: f_ids) {

                    if (!is_face_inserted[f_id])

                        continue;

                    ps_2d = {{to_2d(input_vertices[input_faces[f_id][0]], t),

                                     to_2d(input_vertices[input_faces[f_id][1]], t),

                                     to_2d(input_vertices[input_faces[f_id][2]], t)}};

                    bool is_in = false;

                    for (auto &c:cs) {

                        if (is_on_bounded_side(ps_2d, c)) {

                            is_in = true;

                            break;

                        }

                    }

                    if (is_in) {

                        ff_id = f_id;

                        is_all_out = false;

                        break;

                    }

                }

                if(is_all_out)

                    continue;

//                int t = get_t(tp1_3d, tp2_3d, tp3_3d);

//                std::array<Vector2, 3> tps_2d = {{to_2d(tp1_3d, t), to_2d(tp2_3d, t), to_2d(tp3_3d, t)}};

//                std::array<Vector2, 4> cs = {{(tps_2d[0] + tps_2d[1] + tps_2d[2]) / 3}};

//                for (int k = 0; k < 3; k++)

//                    cs[k + 1] = (tps_2d[k] + cs[0]) / 3;

//                std::array<Vector2, 3> ps_2d;

//                bool is_all_out = true;

//                for (int f_id: f_ids) {

//                    if (!is_face_inserted[f_id])

//                        continue;

//

//                    ps_2d = {{to_2d(input_vertices[input_faces[f_id][0]], t),

//                                     to_2d(input_vertices[input_faces[f_id][1]], t),

//                                     to_2d(input_vertices[input_faces[f_id][2]], t)}};

//

//                    bool is_in = false;

//                    for (auto &c:cs) {

//                        if (is_on_bounded_side(ps_2d, c)) {

//                            is_in = true;

//                            break;

//                        }

//                    }

//                    if (is_in) {

//                        ff_id = f_id;

//                        is_all_out = false;

//                        break;

//                    }

//                }

//                if(is_all_out)

//                    continue;

//                //

                double eps = (mesh.params.eps + mesh.params.eps_simplification) / 2;

                double dd = (mesh.params.dd + mesh.params.dd_simplification) / 2;

                eps *= eps;