The .rscene and .rprefab format

Run the complete example

In a Reckfell 1.0.0 C# project create these files at the shown paths relative to asset://. Put FormatGallery2D.cs at the project root. Attach it to an Entity2D in a separate level, set a 640×420 base viewport, build C# and press F6. Two blue objects appear. The right one is larger; × deletes only its own instance.

[reckfell_resource type="StyleBoxFlat" format=3]

[resource]
bg_color = Color(0.18, 0.36, 0.95, 1)
corner_radius_top_left = 12
corner_radius_top_right = 12
corner_radius_bottom_left = 12
corner_radius_bottom_right = 12

; This comment is not retained by ResourceSaver.
[reckfell_tree format=3]

[ext_resource type="StyleBox" path="asset://Assets/BadgeStyle.rdata" id="Style"]

[entity name="Badge" type="Entity2D" groups=["format_badges"]]

[entity name="Panel" type="Panel" parent="."]
offset_right = 112.0
offset_bottom = 64.0
mouse_filter = 2
theme_override_styles/panel = ExtResource("Style")

[entity name="Mount" type="Entity2D" parent="."]

[entity name="Pivot" type="Marker2D" parent="."]
unique_name_in_owner = true
position = Vector2(56, 32)

[entity name="Remove" type="Button" parent="."]
offset_left = 76.0
offset_top = 12.0
offset_right = 102.0
offset_bottom = 52.0
text = "×"

[connection signal="pressed" from="Remove" to="." method="queue_free"]

[reckfell_tree format=3]

[ext_resource type="PackedEntity" path="asset://Actors/Badge.rprefab" id="Badge"]

[entity name="FormatShowcase" type="Entity2D"]

[entity name="Left" parent="." instance=ExtResource("Badge")]
position = Vector2(100, 190)

[entity name="Right" parent="." instance=ExtResource("Badge")]
position = Vector2(350, 190)
scale = Vector2(1.25, 1.25)

using Reckfell;

public partial class FormatGallery2D : Entity2D
{
    public Entity2D Gallery { get; private set; } = null!;

    public override void _Ready()
    {
        var packed = ResourceLoader.Load<PackedEntity>("asset://Levels/FormatShowcase.rscene");
        if (packed is null || !packed.CanInstantiate())
        {
            ReckfellApi.PrintErr("Cannot load FormatShowcase.rscene");
            return;
        }
        Gallery = packed.Instantiate<Entity2D>();
        AddChild(Gallery);
        AddChild(new Label
        {
            Position = new Vector2(28, 24),
            Text = TranslationServer.GetLocale().StartsWith("ru")
                ? "Уровень: два экземпляра одного префаба"
                : "Level: two instances of one prefab"
        });
        foreach (string name in new[] { "Left", "Right" })
        {
            var instance = Gallery.GetEntity<Entity2D>(name);
            var pivot = instance.GetEntity<Marker2D>("%Pivot");
            instance.AddChild(new Label { Position = new Vector2(0, 84), Text = name + " · %Pivot " + pivot.Position });
        }
    }
}

Read the tree

The first [reckfell_tree] tag identifies a PackedEntity tree. It is followed by ext_resource, sub_resource when needed, entity and connection entries. A .rdata file starts with [reckfell_resource type="..."]; its main resource properties follow [resource].

id="Badge" is a local reference label, not a global UID. parent is an Entity-tree path, not a filesystem path. Left/Right position and scale are instance overrides; they do not rewrite Badge.rprefab. Both instances use one external StyleBox; changing that shared resource can affect both.

Ordinary child entries restore their owner to the prefab root here. In C#, AddChild alone does not assign Owner; see programmatic packing. The native fixture verifies actual owner scopes and the saved signal rather than only successful text parsing.

UIDs and local identifiers

A header uid="uid://..." identifies the file. An entity unique_id helps serialization track an Entity entry; UniqueNameInOwner and %Pivot instead locate an object within an Owner scope. These values are not interchangeable and are not network IDs.

A UID neither contains the file nor discovers every moved file by itself. It needs a UID → path registry. In runtime, ResourceLoader.GetResourceUid reads that registry; the checked editor-mode source can also read headers through resource loaders. ResourceUid.PathToUid can return the original path when no UID is known. The fresh-process check explicitly rebuilds the generated fixture asset's mapping; it does not establish automatic user:// discovery.

Address player saves in user:// through your own schema and stable gameplay IDs. ResourceSaver.SetUid does not register a runtime mapping. In this checked build, a user:// case returns Ok but leaves a temporary .uidren without replacing the original file; the example does not rely on that method.

Diagnose a failed load

Semicolon comments and optional spacing do not retain their original formatting after saving. The older load_steps field is neither an Entity count nor the engine version; the current saver omits it. Let the editor preserve unique_id/parent_id_path/owner_uid_path for arbitrary nested trees rather than inventing them manually.