Batch import Blend files using XML RPC

This improves performance when importing many Blender files, as it
avoids waiting for Blender to startup every time.
Old logic is still available by setting the RPC port setting to 0.

4 files changed, 450 insertions, 75 deletions

diff --git a/modules/gltf/editor/editor_import_blend_runner.cpp b/modules/gltf/editor/editor_import_blend_runner.cpp
new file mode 100644
index 0000000000..feb6f96752
--- /dev/null
+++ b/modules/gltf/editor/editor_import_blend_runner.cpp
@@ -0,0 +1,314 @@
+/*************************************************************************/
+/*  editor_import_blend_runner.cpp                                       */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "editor_import_blend_runner.h"
+
+#ifdef TOOLS_ENABLED
+
+#include "core/io/http_client.h"
+#include "editor/editor_file_system.h"
+#include "editor/editor_node.h"
+#include "editor/editor_settings.h"
+
+static constexpr char PYTHON_SCRIPT_RPC[] = R"(
+import bpy, sys, threading
+from xmlrpc.server import SimpleXMLRPCServer
+req = threading.Condition()
+res = threading.Condition()
+info = None
+def xmlrpc_server():
+  server = SimpleXMLRPCServer(('127.0.0.1', %d))
+  server.register_function(export_gltf)
+  server.serve_forever()
+def export_gltf(opts):
+  with req:
+    global info
+    info = ('export_gltf', opts)
+    req.notify()
+  with res:
+    res.wait()
+if bpy.app.version < (3, 0, 0):
+  print('Blender 3.0 or higher is required.', file=sys.stderr)
+threading.Thread(target=xmlrpc_server).start()
+while True:
+  with req:
+    while info is None:
+      req.wait()
+  method, opts = info
+  if method == 'export_gltf':
+    try:
+      bpy.ops.wm.open_mainfile(filepath=opts['path'])
+      if opts['unpack_all']:
+        bpy.ops.file.unpack_all(method='USE_LOCAL')
+      bpy.ops.export_scene.gltf(**opts['gltf_options'])
+    except:
+      pass
+  info = None
+  with res:
+    res.notify()
+)";
+
+static constexpr char PYTHON_SCRIPT_DIRECT[] = R"(
+import bpy, sys
+opts = %s
+if bpy.app.version < (3, 0, 0):
+  print('Blender 3.0 or higher is required.', file=sys.stderr)
+bpy.ops.wm.open_mainfile(filepath=opts['path'])
+if opts['unpack_all']:
+  bpy.ops.file.unpack_all(method='USE_LOCAL')
+bpy.ops.export_scene.gltf(**opts['gltf_options'])
+)";
+
+String dict_to_python(const Dictionary &p_dict) {
+	String entries;
+	Array dict_keys = p_dict.keys();
+	for (int i = 0; i < dict_keys.size(); i++) {
+		const String key = dict_keys[i];
+		String value;
+		Variant raw_value = p_dict[key];
+
+		switch (raw_value.get_type()) {
+			case Variant::Type::BOOL: {
+				value = raw_value ? "True" : "False";
+				break;
+			}
+			case Variant::Type::STRING:
+			case Variant::Type::STRING_NAME: {
+				value = raw_value;
+				value = vformat("'%s'", value.c_escape());
+				break;
+			}
+			case Variant::Type::DICTIONARY: {
+				value = dict_to_python(raw_value);
+				break;
+			}
+			default: {
+				ERR_FAIL_V_MSG("", vformat("Unhandled Variant type %s for python dictionary", Variant::get_type_name(raw_value.get_type())));
+			}
+		}
+
+		entries += vformat("'%s': %s,", key, value);
+	}
+	return vformat("{%s}", entries);
+}
+
+String dict_to_xmlrpc(const Dictionary &p_dict) {
+	String members;
+	Array dict_keys = p_dict.keys();
+	for (int i = 0; i < dict_keys.size(); i++) {
+		const String key = dict_keys[i];
+		String value;
+		Variant raw_value = p_dict[key];
+
+		switch (raw_value.get_type()) {
+			case Variant::Type::BOOL: {
+				value = vformat("<boolean>%d</boolean>", raw_value ? 1 : 0);
+				break;
+			}
+			case Variant::Type::STRING:
+			case Variant::Type::STRING_NAME: {
+				value = raw_value;
+				value = vformat("<string>%s</string>", value.xml_escape());
+				break;
+			}
+			case Variant::Type::DICTIONARY: {
+				value = dict_to_xmlrpc(raw_value);
+				break;
+			}
+			default: {
+				ERR_FAIL_V_MSG("", vformat("Unhandled Variant type %s for XMLRPC", Variant::get_type_name(raw_value.get_type())));
+			}
+		}
+
+		members += vformat("<member><name>%s</name><value>%s</value></member>", key, value);
+	}
+	return vformat("<struct>%s</struct>", members);
+}
+
+Error EditorImportBlendRunner::start_blender(const String &p_python_script, bool p_blocking) {
+	String blender_path = EDITOR_GET("filesystem/import/blender/blender3_path");
+
+#ifdef WINDOWS_ENABLED
+	blender_path = blender_path.path_join("blender.exe");
+#else
+	blender_path = blender_path.path_join("blender");
+#endif
+
+	List<String> args;
+	args.push_back("--background");
+	args.push_back("--python-expr");
+	args.push_back(p_python_script);
+
+	Error err;
+	if (p_blocking) {
+		int exitcode = 0;
+		err = OS::get_singleton()->execute(blender_path, args, nullptr, &exitcode);
+		if (exitcode != 0) {
+			return FAILED;
+		}
+	} else {
+		err = OS::get_singleton()->create_process(blender_path, args, &blender_pid);
+	}
+	return err;
+}
+
+Error EditorImportBlendRunner::do_import(const Dictionary &p_options) {
+	if (is_using_rpc()) {
+		return do_import_rpc(p_options);
+	} else {
+		return do_import_direct(p_options);
+	}
+}
+
+Error EditorImportBlendRunner::do_import_rpc(const Dictionary &p_options) {
+	kill_timer->stop();
+
+	// Start Blender if not already running.
+	if (!is_running()) {
+		// Start an XML RPC server on the given port.
+		String python = vformat(PYTHON_SCRIPT_RPC, rpc_port);
+		Error err = start_blender(python, false);
+		if (err != OK || blender_pid == 0) {
+			return FAILED;
+		}
+	}
+
+	// Convert options to XML body.
+	String xml_options = dict_to_xmlrpc(p_options);
+	String xml_body = vformat("<?xml version=\"1.0\"?><methodCall><methodName>export_gltf</methodName><params><param><value>%s</value></param></params></methodCall>", xml_options);
+
+	// Connect to RPC server.
+	Ref<HTTPClient> client = HTTPClient::create();
+	client->connect_to_host("127.0.0.1", rpc_port);
+
+	bool done = false;
+	while (!done) {
+		HTTPClient::Status status = client->get_status();
+		switch (status) {
+			case HTTPClient::STATUS_RESOLVING:
+			case HTTPClient::STATUS_CONNECTING: {
+				client->poll();
+				break;
+			}
+			case HTTPClient::STATUS_CONNECTED: {
+				done = true;
+				break;
+			}
+			default: {
+				ERR_FAIL_V_MSG(ERR_CONNECTION_ERROR, vformat("Unexpected status during RPC connection: %d", status));
+			}
+		}
+	}
+
+	// Send XML request.
+	PackedByteArray xml_buffer = xml_body.to_utf8_buffer();
+	Error err = client->request(HTTPClient::METHOD_POST, "/", Vector<String>(), xml_buffer.ptr(), xml_buffer.size());
+	if (err != OK) {
+		ERR_FAIL_V_MSG(err, vformat("Unable to send RPC request: %d", err));
+	}
+
+	// Wait for response.
+	done = false;
+	while (!done) {
+		HTTPClient::Status status = client->get_status();
+		switch (status) {
+			case HTTPClient::STATUS_REQUESTING: {
+				client->poll();
+				break;
+			}
+			case HTTPClient::STATUS_BODY: {
+				client->poll();
+				// Parse response here if needed. For now we can just ignore it.
+				done = true;
+				break;
+			}
+			default: {
+				ERR_FAIL_V_MSG(ERR_CONNECTION_ERROR, vformat("Unexpected status during RPC response: %d", status));
+			}
+		}
+	}
+
+	return OK;
+}
+
+Error EditorImportBlendRunner::do_import_direct(const Dictionary &p_options) {
+	// Export glTF directly.
+	String python = vformat(PYTHON_SCRIPT_DIRECT, dict_to_python(p_options));
+	Error err = start_blender(python, true);
+	if (err != OK) {
+		return err;
+	}
+
+	return OK;
+}
+
+void EditorImportBlendRunner::_resources_reimported(const PackedStringArray &p_files) {
+	if (is_running()) {
+		// After a batch of imports is done, wait a few seconds before trying to kill blender,
+		// in case of having multiple imports trigger in quick succession.
+		kill_timer->start();
+	}
+}
+
+void EditorImportBlendRunner::_kill_blender() {
+	kill_timer->stop();
+	if (is_running()) {
+		OS::get_singleton()->kill(blender_pid);
+	}
+	blender_pid = 0;
+}
+
+void EditorImportBlendRunner::_notification(int p_what) {
+	switch (p_what) {
+		case NOTIFICATION_PREDELETE: {
+			_kill_blender();
+			break;
+		}
+	}
+}
+
+EditorImportBlendRunner *EditorImportBlendRunner::singleton = nullptr;
+
+EditorImportBlendRunner::EditorImportBlendRunner() {
+	ERR_FAIL_COND_MSG(singleton != nullptr, "EditorImportBlendRunner already created.");
+	singleton = this;
+
+	rpc_port = EDITOR_GET("filesystem/import/blender/rpc_port");
+
+	kill_timer = memnew(Timer);
+	add_child(kill_timer);
+	kill_timer->set_one_shot(true);
+	kill_timer->set_wait_time(EDITOR_GET("filesystem/import/blender/rpc_server_uptime"));
+	kill_timer->connect("timeout", callable_mp(this, &EditorImportBlendRunner::_kill_blender));
+
+	EditorFileSystem::get_singleton()->connect("resources_reimported", callable_mp(this, &EditorImportBlendRunner::_resources_reimported));
+}
+
+#endif // TOOLS_ENABLED
diff --git a/modules/gltf/editor/editor_import_blend_runner.h b/modules/gltf/editor/editor_import_blend_runner.h
new file mode 100644
index 0000000000..d3c3976c13
--- /dev/null
+++ b/modules/gltf/editor/editor_import_blend_runner.h
@@ -0,0 +1,69 @@
+/*************************************************************************/
+/*  editor_import_blend_runner.h                                         */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef EDITOR_IMPORT_BLEND_RUNNER_H
+#define EDITOR_IMPORT_BLEND_RUNNER_H
+
+#ifdef TOOLS_ENABLED
+
+#include "core/os/os.h"
+#include "scene/main/node.h"
+#include "scene/main/timer.h"
+
+class EditorImportBlendRunner : public Node {
+	GDCLASS(EditorImportBlendRunner, Node);
+
+	static EditorImportBlendRunner *singleton;
+
+	Timer *kill_timer;
+	void _resources_reimported(const PackedStringArray &p_files);
+	void _kill_blender();
+	void _notification(int p_what);
+
+protected:
+	int rpc_port = 0;
+	OS::ProcessID blender_pid = 0;
+	Error start_blender(const String &p_python_script, bool p_blocking);
+	Error do_import_direct(const Dictionary &p_options);
+	Error do_import_rpc(const Dictionary &p_options);
+
+public:
+	static EditorImportBlendRunner *get_singleton() { return singleton; }
+
+	bool is_running() { return blender_pid != 0 && OS::get_singleton()->is_process_running(blender_pid); }
+	bool is_using_rpc() { return rpc_port != 0; }
+	Error do_import(const Dictionary &p_options);
+
+	EditorImportBlendRunner();
+};
+
+#endif // TOOLS_ENABLED
+
+#endif // EDITOR_IMPORT_BLEND_RUNNER_H
diff --git a/modules/gltf/editor/editor_scene_importer_blend.cpp b/modules/gltf/editor/editor_scene_importer_blend.cpp
index 4dafa746bc..c5e7337914 100644
--- a/modules/gltf/editor/editor_scene_importer_blend.cpp
+++ b/modules/gltf/editor/editor_scene_importer_blend.cpp
@@ -33,6 +33,7 @@
 #ifdef TOOLS_ENABLED
 
 #include "../gltf_document.h"
+#include "editor_import_blend_runner.h"
 
 #include "core/config/project_settings.h"
 #include "editor/editor_file_dialog.h"
@@ -68,149 +69,129 @@ Node *EditorSceneFormatImporterBlend::import_scene(const String &p_path, uint32_
 
 	// Handle configuration options.
 
-	String parameters_arg;
+	Dictionary request_options;
+	Dictionary parameters_map;
+
+	parameters_map["filepath"] = sink_global;
+	parameters_map["export_keep_originals"] = true;
+	parameters_map["export_format"] = "GLTF_SEPARATE";
+	parameters_map["export_yup"] = true;
 
 	if (p_options.has(SNAME("blender/nodes/custom_properties")) && p_options[SNAME("blender/nodes/custom_properties")]) {
-		parameters_arg += "export_extras=True,";
+		parameters_map["export_extras"] = true;
 	} else {
-		parameters_arg += "export_extras=False,";
+		parameters_map["export_extras"] = false;
 	}
 	if (p_options.has(SNAME("blender/meshes/skins"))) {
 		int32_t skins = p_options["blender/meshes/skins"];
 		if (skins == BLEND_BONE_INFLUENCES_NONE) {
-			parameters_arg += "export_skins=False,";
+			parameters_map["export_skins"] = false;
 		} else if (skins == BLEND_BONE_INFLUENCES_COMPATIBLE) {
-			parameters_arg += "export_all_influences=False,export_skins=True,";
+			parameters_map["export_skins"] = true;
+			parameters_map["export_all_influences"] = false;
 		} else if (skins == BLEND_BONE_INFLUENCES_ALL) {
-			parameters_arg += "export_all_influences=True,export_skins=True,";
+			parameters_map["export_skins"] = true;
+			parameters_map["export_all_influences"] = true;
 		}
 	} else {
-		parameters_arg += "export_skins=False,";
+		parameters_map["export_skins"] = false;
 	}
 	if (p_options.has(SNAME("blender/materials/export_materials"))) {
 		int32_t exports = p_options["blender/materials/export_materials"];
 		if (exports == BLEND_MATERIAL_EXPORT_PLACEHOLDER) {
-			parameters_arg += "export_materials='PLACEHOLDER',";
+			parameters_map["export_materials"] = "PLACEHOLDER";
 		} else if (exports == BLEND_MATERIAL_EXPORT_EXPORT) {
-			parameters_arg += "export_materials='EXPORT',";
+			parameters_map["export_materials"] = "EXPORT";
 		}
 	} else {
-		parameters_arg += "export_materials='PLACEHOLDER',";
+		parameters_map["export_materials"] = "PLACEHOLDER";
 	}
 	if (p_options.has(SNAME("blender/nodes/cameras")) && p_options[SNAME("blender/nodes/cameras")]) {
-		parameters_arg += "export_cameras=True,";
+		parameters_map["export_cameras"] = true;
 	} else {
-		parameters_arg += "export_cameras=False,";
+		parameters_map["export_cameras"] = false;
 	}
 	if (p_options.has(SNAME("blender/nodes/punctual_lights")) && p_options[SNAME("blender/nodes/punctual_lights")]) {
-		parameters_arg += "export_lights=True,";
+		parameters_map["export_lights"] = true;
 	} else {
-		parameters_arg += "export_lights=False,";
+		parameters_map["export_lights"] = false;
 	}
 	if (p_options.has(SNAME("blender/meshes/colors")) && p_options[SNAME("blender/meshes/colors")]) {
-		parameters_arg += "export_colors=True,";
+		parameters_map["export_colors"] = true;
 	} else {
-		parameters_arg += "export_colors=False,";
+		parameters_map["export_colors"] = false;
 	}
 	if (p_options.has(SNAME("blender/nodes/visible"))) {
 		int32_t visible = p_options["blender/nodes/visible"];
 		if (visible == BLEND_VISIBLE_VISIBLE_ONLY) {
-			parameters_arg += "use_visible=True,";
+			parameters_map["use_visible"] = true;
 		} else if (visible == BLEND_VISIBLE_RENDERABLE) {
-			parameters_arg += "use_renderable=True,";
+			parameters_map["use_renderable"] = true;
 		} else if (visible == BLEND_VISIBLE_ALL) {
-			parameters_arg += "use_visible=False,use_renderable=False,";
+			parameters_map["use_renderable"] = false;
+			parameters_map["use_visible"] = false;
 		}
 	} else {
-		parameters_arg += "use_visible=False,use_renderable=False,";
+		parameters_map["use_renderable"] = false;
+		parameters_map["use_visible"] = false;
 	}
 
 	if (p_options.has(SNAME("blender/meshes/uvs")) && p_options[SNAME("blender/meshes/uvs")]) {
-		parameters_arg += "export_texcoords=True,";
+		parameters_map["export_texcoords"] = true;
 	} else {
-		parameters_arg += "export_texcoords=False,";
+		parameters_map["export_texcoords"] = false;
 	}
 	if (p_options.has(SNAME("blender/meshes/normals")) && p_options[SNAME("blender/meshes/normals")]) {
-		parameters_arg += "export_normals=True,";
+		parameters_map["export_normals"] = true;
 	} else {
-		parameters_arg += "export_normals=False,";
+		parameters_map["export_normals"] = false;
 	}
 	if (p_options.has(SNAME("blender/meshes/tangents")) && p_options[SNAME("blender/meshes/tangents")]) {
-		parameters_arg += "export_tangents=True,";
+		parameters_map["export_tangents"] = true;
 	} else {
-		parameters_arg += "export_tangents=False,";
+		parameters_map["export_tangents"] = false;
 	}
 	if (p_options.has(SNAME("blender/animation/group_tracks")) && p_options[SNAME("blender/animation/group_tracks")]) {
-		parameters_arg += "export_nla_strips=True,";
+		parameters_map["export_nla_strips"] = true;
 	} else {
-		parameters_arg += "export_nla_strips=False,";
+		parameters_map["export_nla_strips"] = false;
 	}
 	if (p_options.has(SNAME("blender/animation/limit_playback")) && p_options[SNAME("blender/animation/limit_playback")]) {
-		parameters_arg += "export_frame_range=True,";
+		parameters_map["export_frame_range"] = true;
 	} else {
-		parameters_arg += "export_frame_range=False,";
+		parameters_map["export_frame_range"] = false;
 	}
 	if (p_options.has(SNAME("blender/animation/always_sample")) && p_options[SNAME("blender/animation/always_sample")]) {
-		parameters_arg += "export_force_sampling=True,";
+		parameters_map["export_force_sampling"] = true;
 	} else {
-		parameters_arg += "export_force_sampling=False,";
+		parameters_map["export_force_sampling"] = false;
 	}
 	if (p_options.has(SNAME("blender/meshes/export_bones_deforming_mesh_only")) && p_options[SNAME("blender/meshes/export_bones_deforming_mesh_only")]) {
-		parameters_arg += "export_def_bones=True,";
+		parameters_map["export_def_bones"] = true;
 	} else {
-		parameters_arg += "export_def_bones=False,";
+		parameters_map["export_def_bones"] = false;
 	}
 	if (p_options.has(SNAME("blender/nodes/modifiers")) && p_options[SNAME("blender/nodes/modifiers")]) {
-		parameters_arg += "export_apply=True";
+		parameters_map["export_apply"] = true;
 	} else {
-		parameters_arg += "export_apply=False";
+		parameters_map["export_apply"] = false;
 	}
 
-	String unpack_all;
 	if (p_options.has(SNAME("blender/materials/unpack_enabled")) && p_options[SNAME("blender/materials/unpack_enabled")]) {
-		unpack_all = "bpy.ops.file.unpack_all(method='USE_LOCAL');";
+		request_options["unpack_all"] = true;
+	} else {
+		request_options["unpack_all"] = false;
 	}
 
-	// Prepare Blender export script.
-
-	String common_args = vformat("filepath='%s',", sink_global) +
-			"export_format='GLTF_SEPARATE',"
-			"export_yup=True," +
-			parameters_arg;
-	String export_script =
-			String("import bpy, sys;") +
-			"print('Blender 3.0 or higher is required.', file=sys.stderr) if bpy.app.version < (3, 0, 0) else None;" +
-			vformat("bpy.ops.wm.open_mainfile(filepath='%s');", source_global) +
-			unpack_all +
-			vformat("bpy.ops.export_scene.gltf(export_keep_originals=True,%s);", common_args);
-	print_verbose(export_script);
-
-	// Run script with configured Blender binary.
+	request_options["path"] = source_global;
+	request_options["gltf_options"] = parameters_map;
 
-	String blender_path = EDITOR_GET("filesystem/import/blender/blender3_path");
-
-#ifdef WINDOWS_ENABLED
-	blender_path = blender_path.path_join("blender.exe");
-#else
-	blender_path = blender_path.path_join("blender");
-#endif
-
-	List<String> args;
-	args.push_back("--background");
-	args.push_back("--python-expr");
-	args.push_back(export_script);
-
-	String standard_out;
-	int ret;
-	OS::get_singleton()->execute(blender_path, args, &standard_out, &ret, true);
-	print_verbose(blender_path);
-	print_verbose(standard_out);
-
-	if (ret != 0) {
+	// Run Blender and export glTF.
+	Error err = EditorImportBlendRunner::get_singleton()->do_import(request_options);
+	if (err != OK) {
 		if (r_err) {
 			*r_err = ERR_SCRIPT_FAILED;
 		}
-		ERR_PRINT(vformat("Blend export to glTF failed with error: %d.", ret));
 		return nullptr;
 	}
 
@@ -225,7 +206,7 @@ Node *EditorSceneFormatImporterBlend::import_scene(const String &p_path, uint32_
 	if (p_options.has(SNAME("blender/materials/unpack_enabled")) && p_options[SNAME("blender/materials/unpack_enabled")]) {
 		base_dir = sink.get_base_dir();
 	}
-	Error err = gltf->append_from_file(sink.get_basename() + ".gltf", state, p_flags, base_dir);
+	err = gltf->append_from_file(sink.get_basename() + ".gltf", state, p_flags, base_dir);
 	if (err != OK) {
 		if (r_err) {
 			*r_err = FAILED;
diff --git a/modules/gltf/register_types.cpp b/modules/gltf/register_types.cpp
index cd7a23fbb2..f3fa00cae3 100644
--- a/modules/gltf/register_types.cpp
+++ b/modules/gltf/register_types.cpp
@@ -36,6 +36,7 @@
 
 #ifdef TOOLS_ENABLED
 #include "core/config/project_settings.h"
+#include "editor/editor_import_blend_runner.h"
 #include "editor/editor_node.h"
 #include "editor/editor_scene_exporter_gltf_plugin.h"
 #include "editor/editor_scene_importer_blend.h"
@@ -52,6 +53,14 @@ static void _editor_init() {
 
 	bool blend_enabled = GLOBAL_GET("filesystem/import/blender/enabled");
 	// Defined here because EditorSettings doesn't exist in `register_gltf_types` yet.
+	EDITOR_DEF_RST("filesystem/import/blender/rpc_port", 6011);
+	EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::INT,
+			"filesystem/import/blender/rpc_port", PROPERTY_HINT_RANGE, "0,65535,1"));
+
+	EDITOR_DEF_RST("filesystem/import/blender/rpc_server_uptime", 5);
+	EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::FLOAT,
+			"filesystem/import/blender/rpc_server_uptime", PROPERTY_HINT_RANGE, "0,300,1,or_greater,suffix:s"));
+
 	String blender3_path = EDITOR_DEF_RST("filesystem/import/blender/blender3_path", "");
 	EditorSettings::get_singleton()->add_property_hint(PropertyInfo(Variant::STRING,
 			"filesystem/import/blender/blender3_path", PROPERTY_HINT_GLOBAL_DIR));
@@ -71,6 +80,8 @@ static void _editor_init() {
 			EditorFileSystem::get_singleton()->add_import_format_support_query(blend_import_query);
 		}
 	}
+	memnew(EditorImportBlendRunner);
+	EditorNode::get_singleton()->add_child(EditorImportBlendRunner::get_singleton());
 
 	// FBX to glTF importer.