feat(export obj): add obj export in process.cpp

network_process/src/process.cpp

@@ -4,6 +4,89 @@
 #include <connect_by_topo.hpp>
 #include <post_topo.hpp>
 
+#include <fstream>
+
+
+void export_halfpatch_obj(
+    const stl_vector_mp<Eigen::Vector3d>& iso_pts,
+    const stl_vector_mp<polygon_face_t>& iso_faces,
+    const stl_vector_mp<stl_vector_mp<uint32_t>>& patches,
+    const std::string& filename)
+{
+    std::string mtl_filename = filename + ".mtl";
+    std::ofstream mtl(mtl_filename);
+    for (size_t half_patch = 0; half_patch < patches.size() * 2; ++half_patch) {
+        size_t patch_idx = half_patch / 2;
+        bool is_forward = (half_patch % 2 == 0);
+        mtl << "newmtl patch_" << patch_idx << (is_forward ? "_in" : "_out") << "\n";
+        // 随机或规律分配颜色
+        float r = float(patch_idx % 7) / 7.0f;
+        float g = is_forward ? 0.8f : 0.2f;
+        float b = 1.0f - r;
+        mtl << "Kd " << r << " " << g << " " << b << "\n";
+    }
+    mtl.close();
+
+    std::string obj_filename = filename + ".obj";
+    std::ofstream ofs(obj_filename);
+    if (!ofs) return;
+
+    ofs << "mtllib "<< mtl_filename << "\n";
+
+    // 输出所有顶点
+    for (const auto& v : iso_pts) {
+        ofs << "v " << v.x() << " " << v.y() << " " << v.z() << "\n";
+    }
+
+    // 遍历所有 half-patch
+    for (size_t half_patch = 0; half_patch < patches.size() * 2; ++half_patch) {
+        size_t patch_idx = half_patch / 2;
+        bool is_forward = (half_patch % 2 == 0);
+        ofs << "g halfpatch_" << half_patch << "\n";
+        ofs << "usemtl patch_" << patch_idx << (is_forward ? "_in" : "_out") << "\n";
+        for (auto face_idx : patches[patch_idx]) {
+            const auto& face = iso_faces[face_idx];
+            ofs << "f";
+            if (is_forward) {
+                for (auto vi : face.vertex_indices)
+                    ofs << " " << (vi + 1);
+            } else {
+                for (auto it = face.vertex_indices.rbegin(); it != face.vertex_indices.rend(); ++it)
+                    ofs << " " << (*it + 1);
+            }
+            ofs << "\n";
+        }
+    }
+    ofs.close();
+}
+
+
+// Export OBJ without patch information
+void export_obj_no_patch(
+    const stl_vector_mp<Eigen::Vector3d>& iso_pts,
+    const stl_vector_mp<polygon_face_t>& iso_faces,
+    const std::string& filename)
+{
+    // Write OBJ file
+    std::string obj_filename = filename + ".obj";
+    std::ofstream ofs(obj_filename);
+    if (!ofs) return;
+
+    // Write all vertices
+    for (const auto& v : iso_pts) {
+        ofs << "v " << v.x() << " " << v.y() << " " << v.z() << "\n";
+    }
+
+    // Write all faces
+    for (const auto& face : iso_faces) {
+        ofs << "f";
+        for (auto vi : face.vertex_indices)
+            ofs << " " << (vi + 1);
+        ofs << "\n";
+    }
+    ofs.close();
+}
+
 ISNP_API void build_implicit_network_by_blobtree(const s_settings&                                settings,
                                                  const baked_blobtree_t&                          tree,
                                                  stl_vector_mp<Eigen::Vector3d>&                  output_vertices,
@@ -71,6 +154,7 @@ ISNP_API void build_implicit_network_by_blobtree(const s_settings&
                          iso_verts,
                          iso_faces);
     }
+    export_obj_no_patch(iso_pts, iso_faces, "halfpatch_bbefore_connect");
     // connect components by topology
     stl_vector_mp<uint32_t>                             patch_of_face(iso_faces.size());
     stl_vector_mp<uint32_t>                             shell_of_half_patch{};
@@ -91,6 +175,10 @@ ISNP_API void build_implicit_network_by_blobtree(const s_settings&
             compute_patch_edges(iso_faces, edges_of_iso_face, iso_edges);
             compute_patches(edges_of_iso_face, iso_edges, iso_faces, patches, patch_of_face);
             compute_chains(iso_verts.size(), iso_edges, chain_vertices, chain_headers, chain_of_mid_face);
+            export_halfpatch_obj(iso_pts, iso_faces, patches, "halfpatch_before_connect");
+            for (auto &subface : tree.subfaces) {
+                std::cout << subface.object_ptr->data_center << std::endl;
+            }
             for (const auto& [face_index, chain_indices] : chain_of_mid_face) {
                 auto& chain_indices_ = chain_of_patch[patch_of_face[face_index]];
                 chain_indices_       = std::move(chain_indices);
@@ -189,5 +277,6 @@ ISNP_API void build_implicit_network_by_blobtree(const s_settings&
                 identify_chain_near_parallel(output_parameteric_planes);
             }
         }
+        export_halfpatch_obj(iso_pts, iso_faces, patches, "halfpatch_final");
     }
 }