feat(web): materialize geometry nodes in Blender Main

blender-5.2.0/source/blender/web_engine/web_engine_main_state.cpp

@@ -4637,9 +4637,9 @@ bool web_engine_blend_main_set_geometry_node_graph(WebBlendMainState *state,
       error = "GN_INVALID_GRAPH: Geometry Node graph could not be persisted in Main";
       return false;
     }
-    /* Materialize a native GeometryNodeTree datablock as the durable owner of
-     * this graph. The bounded JSON remains the transport representation, while
-     * future node-family slices can populate the tree incrementally. */
+    /* Materialize the bounded graph into a native GeometryNodeTree. The JSON
+     * remains the lossless transport record, while Blender owns the editable
+     * node instances and links used by the modifier. */
     bNodeTree *native_tree = nullptr;
     for (bNodeTree &candidate : state->main->nodetrees) {
       if (id_name(candidate.id) == graph_id) {
@@ -4656,6 +4656,60 @@ bool web_engine_blend_main_set_geometry_node_graph(WebBlendMainState *state,
       error = "GN_INVALID_GRAPH: Blender could not create a GeometryNodeTree datablock";
       return false;
     }
+    while (native_tree->nodes.first != nullptr) {
+      bke::node_remove_node(state->main,
+                            *native_tree,
+                            *static_cast<bNode *>(native_tree->nodes.first),
+                            true);
+    }
+    std::unordered_map<std::string, bNode *> native_nodes;
+    for (const json &node : graph["nodes"]) {
+      const std::string node_id = node.value("id", "");
+      const std::string node_type = node.value("type", "");
+      const std::string node_name = node.value("name", node_id);
+      if (node_id.empty() || node_type.empty() || node_name.empty()) {
+        error = "GN_INVALID_GRAPH: Geometry Node node identity is incomplete";
+        return false;
+      }
+      if (bke::node_type_find(UString(node_type)) == nullptr) {
+        error = "GN_NODE_UNSUPPORTED: Blender does not register the requested Geometry Node type";
+        return false;
+      }
+      bNode *native = bke::node_add_node(nullptr, *native_tree, UString(node_type));
+      if (native == nullptr) {
+        error = "GN_INVALID_GRAPH: Blender could not materialize a Geometry Node";
+        return false;
+      }
+      STRNCPY_UTF8(native->name, node_name.c_str());
+      STRNCPY_UTF8(native->label, node_name.c_str());
+      native_nodes.emplace(node_id, native);
+    }
+    const auto socket_for = [](bNode &node, const eNodeSocketInOut direction, const std::string &socket_id) -> bNodeSocket * {
+      const size_t separator = socket_id.rfind(':');
+      const std::string identifier = separator == std::string::npos ? socket_id : socket_id.substr(separator + 1);
+      ListBase *sockets = direction == SOCK_IN ? &node.inputs : &node.outputs;
+      for (bNodeSocket *socket = static_cast<bNodeSocket *>(sockets->first); socket != nullptr; socket = socket->next) {
+        if (identifier == socket->identifier || identifier == socket->name || socket_id == socket->identifier) return socket;
+      }
+      return nullptr;
+    };
+    for (const json &link : graph["links"]) {
+      const std::string from_id = link.value("fromNodeId", "");
+      const std::string to_id = link.value("toNodeId", "");
+      if (!native_nodes.contains(from_id) || !native_nodes.contains(to_id)) {
+        error = "GN_INVALID_GRAPH: Geometry Node link references a missing node";
+        return false;
+      }
+      bNodeSocket *from = socket_for(*native_nodes.at(from_id), SOCK_OUT, link.value("fromSocketId", ""));
+      bNodeSocket *to = socket_for(*native_nodes.at(to_id), SOCK_IN, link.value("toSocketId", ""));
+      if (from == nullptr || to == nullptr) {
+        error = "GN_INVALID_GRAPH: Geometry Node link references an unavailable socket";
+        return false;
+      }
+      bke::node_add_link(*native_tree, *native_nodes.at(from_id), *from, *native_nodes.at(to_id), *to);
+    }
+    BKE_ntree_update_tag_all(native_tree);
+    BKE_ntree_update_after_single_tree_change(*state->main, *native_tree);
     Object *target_object = find_mesh_object(state->main, mesh_id);
     NodesModifierData *nodes_modifier = nullptr;
     if (target_object != nullptr) {