Rig UI
======

The Rig UI section provides specialized controls for Sakura's Character Rigs (SACR). The UI is automatically registered in the 3D Viewport sidebar under the **Sedaia** tab.

SACR R7 UI Submodules
---------------------

The interface for SACR R7 is split into two major versions and several specialized panels:

Global Settings
~~~~~~~~~~~~~~~
The **Global** panels contain settings that affect the entire rig:

*   **Rig Configuration**: Controls for the overall rig behavior.
*   **Arm and Leg Settings**: Specific IK/FK switches and appearance options.
*   **Arm Type**: An Enum property that selects the arm design (linked to legacy `ArmType` on the rig's internal `Rig_Properties` bone).

Face Settings
~~~~~~~~~~~~~
The **Face** panels focus on the character's facial features:

*   **Eyes and Mouth**: Controls for facial expressions and visibility.
*   **Lash Style**: An Enum property that selects the eyelash style (linked to legacy `Eyelashes` on the `Eye_Properties` bone).
*   **Irises and Sclera**: Material-specific options for eye appearance.

Object-Specific Properties
--------------------------

In Version 4.0, all UI settings are stored within a `PropertyGroup` attached to the **Object** data-block (`bpy.types.Object`).

**Why this is better:**
-   **No Pollution**: Previously, settings were stored in the local PoseBone, meaning the same property would be used for multiple versions and rigs.
-   **Independence**: Now, you can have a "Blue" character and a "Red" character in the same file with independent `Arm Type` or `Lash Style` settings.

Backward Compatibility
----------------------

The extension features a **Synchronization System** that bridges the new UI properties with the rig's internal custom properties. 

If you change a setting in the UI, the extension automatically updates the corresponding custom property on the rig's internal bones (`Rig_Properties` or `Eye_Properties`). This ensures that legacy rigs (e.g., SACR R7.4.1) continue to function exactly as expected.