Can export unit to file (.unit , .material , .mesh, .fbx , .importer_settings) when right clicking on a unit from the level tree

tools/core/database.vala

@@ -421,7 +421,6 @@ public class Database
 
 		reset();
 	}
-
 	/// Resets database to clean state.
 	public void reset()
 	{
@@ -1158,7 +1157,10 @@ public class Database
 	{
 		return get_property(id, key) != null;
 	}
-
+    public Project get_project()
+    {
+        return _project;
+    }
 	public Value? get_property(Guid id, string key)
 	{
 		assert(has_object(id));

tools/level_editor/level_editor.vala

@@ -1117,6 +1117,10 @@ public class LevelEditorApplication : Gtk.Application
 		}
 	}
 
+	public DataCompiler get_data_compiler() {
+		return _data_compiler;
+	}
+
 	protected override void activate()
 	{
 		if (this.active_window == null) {

tools/level_editor/level_tree_view.vala

@@ -221,7 +221,7 @@ public class LevelTreeView : Gtk.Box
 		this.pack_start(tree_control, false, true, 0);
 		this.pack_start(_scrolled_window, true, true, 0);
 	}
-
+	
 	private bool on_button_pressed(Gdk.EventButton ev)
 	{
 		if (ev.button == Gdk.BUTTON_SECONDARY) {
@@ -239,6 +239,64 @@ public class LevelTreeView : Gtk.Box
 			Gtk.Menu menu = new Gtk.Menu();
 			Gtk.MenuItem mi;
 
+			mi = new Gtk.MenuItem.with_label("Export Unit...");
+			mi.activate.connect(() => {
+				Guid unit_id = GUID_ZERO;
+				string unit_name = "";
+
+				// Get selected unit GUID and name
+				_tree_selection.selected_foreach((model, path, iter) => {
+					Value guid_val;
+					model.get_value(iter, Column.GUID, out guid_val);
+					unit_id = (Guid)guid_val;
+
+					Value name_val;
+					model.get_value(iter, Column.NAME, out name_val);
+					unit_name = (string)name_val;
+				});
+
+				if (unit_id == GUID_ZERO) return;
+
+				// Create save dialog
+				var dialog = new Gtk.FileChooserDialog("Export Unit",
+					(Gtk.Window)this.get_toplevel(),
+					Gtk.FileChooserAction.SAVE,
+					"Cancel", Gtk.ResponseType.CANCEL,
+					"Export", Gtk.ResponseType.ACCEPT);
+				// Set the initial folder to _db.get_project().source_dir()
+				dialog.set_current_folder(_db.get_project().source_dir());
+				// Set default name
+				dialog.set_current_name(unit_name.has_suffix(".unit") ? unit_name : unit_name + ".unit");
+
+				// File filter
+				var filter = new Gtk.FileFilter();
+				filter.add_pattern("*.unit");
+				dialog.set_filter(filter);
+
+				if (dialog.run() == (int)Gtk.ResponseType.ACCEPT) {
+					string export_path = dialog.get_filename();
+					if (!export_path.has_suffix(".unit")) {
+						export_path += ".unit";
+					}
+
+					// Get unit and export
+					Unit unit = Unit(_db, unit_id);
+					if (!UnitExporter.export_to_file(unit,export_path)) {
+						// Show error message
+						var err_dialog = new Gtk.MessageDialog(dialog,
+							Gtk.DialogFlags.MODAL,
+							Gtk.MessageType.ERROR,
+							Gtk.ButtonsType.OK,
+							"Failed to export unit!");
+						err_dialog.run();
+						err_dialog.destroy();
+					}
+				}
+
+				dialog.destroy();
+			});
+			menu.add(mi);
+
 			mi = new Gtk.MenuItem.with_label("Rename...");
 			mi.activate.connect(() => {
 					Gtk.Dialog dg = new Gtk.Dialog.with_buttons("New Name"

tools/level_editor/unit.vala

@@ -46,7 +46,7 @@ public struct Unit
 		set_local_rotation(rot);
 		set_local_scale(scl);
 	}
-
+		
 	public Value? get_component_property(Guid component_id, string key)
 	{
 		Value? val;

tools/level_editor/unit_exporter.vala

@@ -0,0 +1,219 @@
+/*
+ * Copyright (c) 2012-2025 Daniele Bartolini et al.
+ * SPDX-License-Identifier: GPL-3.0-or-later
+ */
+using Gee;
+
+namespace Crown
+{
+    public class UnitExporter
+    {        
+        public static bool export_to_file(Unit unit, string path) {
+            try {
+                // Get the project associated with the unit
+                Project project = unit._db.get_project();
+
+                // Generate a new GUID for the prefab
+                Guid prefab_guid = Guid.new_guid();
+
+                // If duplication is successful, generate the prefab's export data
+                string prefab_data = generate_export_data(unit, new Gee.ArrayList<string>());
+
+                // Write the generated prefab data to the file
+                FileUtils.set_contents(path, prefab_data);
+
+                // Compile the data
+                var app = (LevelEditorApplication)GLib.Application.get_default();
+                DataCompiler dc = app.get_data_compiler();
+                dc.compile.begin(project.data_dir(), project.platform(), (obj, res) => {
+                    try {
+                        dc.compile.end(res);
+                    } catch (Error e) {
+                        error("Data compilation failed after export: %s", e.message);
+                    }
+                });
+
+                return true;
+            } catch (Error e) {
+                error("Export failed: %s", e.message);
+                return false;
+            }
+        }
+        private static string generate_export_data(Unit unit,Gee.List<string> resources) {
+            StringBuilder sb = new StringBuilder();
+            sb.append("_guid = \"%s\"\n".printf(Guid.new_guid().to_string()));
+            sb.append("_type = \"unit\"\n");
+
+            process_components_section(unit, sb, resources);
+
+            process_children_section(unit, sb, resources);
+
+            return sb.str;
+        }
+
+        private static void process_components_section(Unit unit, StringBuilder sb, Gee.List<string> resources) {
+            sb.append("components = [\n");
+
+            HashSet<Guid?> components = new HashSet<Guid?>(Guid.hash_func, Guid.equal_func);
+            collect_direct_components(unit,unit._id, components);
+
+            foreach (Guid? component_id in components) {
+                if (component_id == null) continue;
+                string component_type = unit._db.object_type(component_id);
+                sb.append("\t{\n");
+                sb.append("\t\t_guid = \"%s\"\n".printf(Guid.new_guid().to_string()));
+                sb.append("\t\t_type = \"%s\"\n".printf(component_type));
+                sb.append("\t\tdata = {\n");
+                if (component_type == "transform") {
+                    process_transform_data(sb, unit, component_id);
+                } else {
+                    string[] keys = unit._db.get_keys(component_id);
+                    foreach (string key in keys) {
+                        if (key == "_type" || key == "_guid" || key == "type") continue;
+                        string cleaned_key = key.replace("data.", "");
+                        Value? val = unit.get_component_property(component_id, key);
+                        if (val != null) {
+                            sb.append("\t\t\t%s = %s\n".printf(cleaned_key, value_to_lua(val)));
+                        }
+                    }
+                }
+                sb.append("\t\t}\n");
+                sb.append("\t\ttype = \"%s\"\n".printf(component_type));
+                sb.append("\t},\n");
+            }
+
+            sb.append("]\n");
+        }
+
+        private static void process_children_section(Unit unit, StringBuilder sb, Gee.List<string> resources) {
+            Gee.Collection<Guid?> children = get_all_children(unit);
+
+            if (children.size > 0) {
+                sb.append("children = [\n");
+
+                foreach (Guid? child_id in children) {
+                    if (child_id == null) continue;
+
+                    Unit child_unit = Unit(unit._db, child_id);
+                    string child_data = generate_export_data(child_unit,resources);
+
+                    string[] lines = child_data.split("\n");
+                    sb.append("\t{\n");
+
+                    foreach (string line in lines) {
+                        if (line.strip().length == 0) continue;
+
+                        if (line.contains("_type = \"transform\"")) {
+                            process_transform_data(sb, unit, child_id);
+                        }
+
+                        sb.append("\t\t%s\n".printf(line));
+                    }
+                    sb.append("\t},\n");
+                }
+
+                sb.append("]\n");
+            }
+        }
+
+        private static void process_transform_data(StringBuilder sb, Unit unit, Guid? component_id) {
+            sb.append("\t\t\tposition = [0.000, 0.000, 0.000]\n");
+
+            Value? rotation = unit.get_component_property(component_id, "data.rotation");
+            if (rotation != null) {
+                sb.append("\t\t\trotation = %s\n".printf(value_to_lua(rotation)));
+            } else {
+                sb.append("\t\t\trotation = [0.000, 0.000, 0.000, 1.000]\n");
+            }
+
+            Value? scale = unit.get_component_property(component_id, "data.scale");
+            if (scale != null) {
+                sb.append("\t\t\tscale = %s\n".printf(value_to_lua(scale)));
+            } else {
+                sb.append("\t\t\tscale = [1.000, 1.000, 1.000]\n");
+            }
+        }
+
+        private static Gee.Collection<Guid?> get_all_children(Unit unit) {
+            Gee.ArrayList<Guid?> children = new Gee.ArrayList<Guid?>();
+            Value? direct_children = unit._db.get_property(unit._id, "children");
+            if (direct_children != null) {
+                children.add_all((Gee.Collection<Guid?>)direct_children);
+            }
+            Value? prefab = unit._db.get_property(unit._id, "prefab");
+            if (prefab != null) {
+                string prefab_path = (string)prefab;
+                Guid prefab_id = resolve_prefab_id(unit, prefab_path);
+
+                if (prefab_id != GUID_ZERO) {
+                    Unit prefab_unit = Unit(unit._db, prefab_id);
+                    children.add_all(get_all_children(prefab_unit));
+                }
+            }
+            return children;
+        }
+
+        private static Guid resolve_prefab_id(Unit unit,string prefab_path) {
+            string unit_path = prefab_path.has_suffix(".unit") 
+                ? prefab_path 
+                : prefab_path + ".unit";
+
+            Guid guid = unit._db.get_property_guid(GUID_ZERO, unit_path);
+
+            if (guid == GUID_ZERO) {
+                warning("Prefab not found: %s", prefab_path);
+            }
+
+            return guid;
+        }
+
+        private static void collect_direct_components(Unit unit,Guid unit_id, Gee.Set<Guid?> components) {
+            Value? direct = unit._db.get_property(unit_id, "components");
+            if (direct != null) {
+                components.add_all((Gee.Collection<Guid?>)direct);
+            }
+
+            Value? prefab = unit._db.get_property(unit_id, "prefab");
+            if (prefab != null) {
+                string prefab_path = (string)prefab;
+                Guid prefab_id = resolve_prefab_id(unit,prefab_path);
+                if (prefab_id != GUID_ZERO) {
+                    collect_direct_components(unit,prefab_id, components);
+                }
+            }
+
+            remove_deleted_components(unit,unit_id, components); 
+        }
+
+        private static void remove_deleted_components(Unit unit,Guid unit_id, Gee.Set<Guid?> components) {
+            string[] deleted_keys = unit._db.get_keys(unit_id);
+            foreach (string key in deleted_keys) {
+                if (key.has_prefix("deleted_components.#")) {
+                    Guid deleted_id = Guid.parse(key.split("#")[1]);
+                    components.remove(deleted_id);
+                }
+            }
+        }
+
+        private static string value_to_lua(Value val) {
+            Type type = val.type();
+            if (type == typeof(string)) {
+                return "\"%s\"".printf((string)val);
+            } else if (type == typeof(Guid)) {
+                return "\"%s\"".printf(((Guid)val).to_string());
+            } else if (type == typeof(bool)) {
+                return ((bool)val) ? "true" : "false";
+            } else if (type == typeof(double)) {
+                return ((double)val).to_string();
+            } else if (type == typeof(Vector3)) {
+                Vector3 v = (Vector3)val;
+                return "[%.3f, %.3f, %.3f]".printf(v.x, v.y, v.z);
+            } else if (type == typeof(Quaternion)) {
+                Quaternion q = (Quaternion)val;
+                return "[%.3f, %.3f, %.3f, %.3f]".printf(q.x, q.y, q.z, q.w);
+            } else {
+                return "nil";
+            }
+        }        
+    }
+}