Move "Create Debug Tangents" into an editor plugin

Instead of exporting the "create_debug_tangents" function via
METHOD_FLAG_EDITOR it gets executed by an editor plugin.

This moves it from the "Manage object properties" menu into a mesh menu. It also adds undo/redo functionality to the create debug tangents option.

editor/plugins/mesh_instance_3d_editor_plugin.cpp

@@ -270,6 +270,24 @@ void MeshInstance3DEditor::_menu_option(int p_option) {
 		case MENU_OPTION_CREATE_OUTLINE_MESH: {
 			outline_dialog->popup_centered(Vector2(200, 90));
 		} break;
+		case MENU_OPTION_CREATE_DEBUG_TANGENTS: {
+			Ref<EditorUndoRedoManager> ur = EditorNode::get_singleton()->get_undo_redo();
+			ur->create_action(TTR("Create Debug Tangents"));
+
+			MeshInstance3D *tangents = node->create_debug_tangents_node();
+
+			if (tangents) {
+				Node *owner = get_tree()->get_edited_scene_root();
+
+				ur->add_do_reference(tangents);
+				ur->add_do_method(node, "add_child", tangents, true);
+				ur->add_do_method(tangents, "set_owner", owner);
+
+				ur->add_undo_method(node, "remove_child", tangents);
+			}
+
+			ur->commit_action();
+		} break;
 		case MENU_OPTION_CREATE_UV2: {
 			Ref<ArrayMesh> mesh2 = node->get_mesh();
 			if (!mesh2.is_valid()) {
@@ -511,6 +529,7 @@ MeshInstance3DEditor::MeshInstance3DEditor() {
 	options->get_popup()->add_separator();
 	options->get_popup()->add_item(TTR("Create Outline Mesh..."), MENU_OPTION_CREATE_OUTLINE_MESH);
 	options->get_popup()->set_item_tooltip(options->get_popup()->get_item_count() - 1, TTR("Creates a static outline mesh. The outline mesh will have its normals flipped automatically.\nThis can be used instead of the StandardMaterial Grow property when using that property isn't possible."));
+	options->get_popup()->add_item(TTR("Create Debug Tangents"), MENU_OPTION_CREATE_DEBUG_TANGENTS);
 	options->get_popup()->add_separator();
 	options->get_popup()->add_item(TTR("View UV1"), MENU_OPTION_DEBUG_UV1);
 	options->get_popup()->add_item(TTR("View UV2"), MENU_OPTION_DEBUG_UV2);

editor/plugins/mesh_instance_3d_editor_plugin.h

@@ -46,6 +46,7 @@ class MeshInstance3DEditor : public Control {
 		MENU_OPTION_CREATE_MULTIPLE_CONVEX_COLLISION_SHAPES,
 		MENU_OPTION_CREATE_NAVMESH,
 		MENU_OPTION_CREATE_OUTLINE_MESH,
+		MENU_OPTION_CREATE_DEBUG_TANGENTS,
 		MENU_OPTION_CREATE_UV2,
 		MENU_OPTION_DEBUG_UV1,
 		MENU_OPTION_DEBUG_UV2,

scene/3d/mesh_instance_3d.cpp

@@ -390,13 +390,13 @@ void MeshInstance3D::_mesh_changed() {
 	update_gizmos();
 }
 
-void MeshInstance3D::create_debug_tangents() {
+MeshInstance3D *MeshInstance3D::create_debug_tangents_node() {
 	Vector<Vector3> lines;
 	Vector<Color> colors;
 
 	Ref<Mesh> mesh = get_mesh();
 	if (!mesh.is_valid()) {
-		return;
+		return nullptr;
 	}
 
 	for (int i = 0; i < mesh->get_surface_count(); i++) {
@@ -457,15 +457,23 @@ void MeshInstance3D::create_debug_tangents() {
 		MeshInstance3D *mi = memnew(MeshInstance3D);
 		mi->set_mesh(am);
 		mi->set_name("DebugTangents");
-		add_child(mi, true);
-#ifdef TOOLS_ENABLED
+		return mi;
+	}
 
-		if (is_inside_tree() && this == get_tree()->get_edited_scene_root()) {
-			mi->set_owner(this);
-		} else {
-			mi->set_owner(get_owner());
-		}
-#endif
+	return nullptr;
+}
+
+void MeshInstance3D::create_debug_tangents() {
+	MeshInstance3D *mi = create_debug_tangents_node();
+	if (!mi) {
+		return;
+	}
+
+	add_child(mi, true);
+	if (is_inside_tree() && this == get_tree()->get_edited_scene_root()) {
+		mi->set_owner(this);
+	} else {
+		mi->set_owner(get_owner());
 	}
 }
 
@@ -495,8 +503,6 @@ void MeshInstance3D::_bind_methods() {
 	ClassDB::bind_method(D_METHOD("set_blend_shape_value", "blend_shape_idx", "value"), &MeshInstance3D::set_blend_shape_value);
 
 	ClassDB::bind_method(D_METHOD("create_debug_tangents"), &MeshInstance3D::create_debug_tangents);
-	ClassDB::set_method_flags("MeshInstance3D", "create_debug_tangents", METHOD_FLAGS_DEFAULT | METHOD_FLAG_EDITOR);
-
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "mesh", PROPERTY_HINT_RESOURCE_TYPE, "Mesh"), "set_mesh", "get_mesh");
 	ADD_GROUP("Skeleton", "");
 	ADD_PROPERTY(PropertyInfo(Variant::OBJECT, "skin", PROPERTY_HINT_RESOURCE_TYPE, "Skin"), "set_skin", "get_skin");

scene/3d/mesh_instance_3d.h

@@ -90,6 +90,7 @@ public:
 	Node *create_multiple_convex_collisions_node();
 	void create_multiple_convex_collisions();
 
+	MeshInstance3D *create_debug_tangents_node();
 	void create_debug_tangents();
 
 	virtual AABB get_aabb() const override;