Meta XR Extensions

This package provides extensions for Meta XR SDK, including the ability to create custom Building Blocks that appear in the Meta XR SDK Building Blocks panel.

Features

• Custom Building Blocks: Create custom Building Blocks that integrate seamlessly with Meta XR SDK
• Easy Creation: Create Building Block assets with a simple context menu
• Automatic Integration: Custom blocks automatically appear in the Building Blocks window alongside Meta's official blocks
• Management Window: View and manage all your custom Building Blocks in one place
• Automatic Injection: Custom blocks are automatically injected into the Building Blocks registry
• UIToolkit Integration: Additional UIToolkit-related Building Blocks and scripts (see UIToolkit section)

Building Blocks Usage

Creating a Building Block

1. Context Menu Method:
   • In the Project window, right-click where you want to create the block
   • Select Create > Meta > Create Building Block
   • A new CustomBlockData asset will be created
   • Configure the block by assigning a prefab, setting the name, description, thumbnail, and other properties

Managing Building Blocks

Open the management window:

• Go to Meta > Building Blocks > Manage Building Blocks

In the management window you can:

• View all custom Building Blocks with thumbnails
• Click on a block to select it and view its details in the Inspector
• See block IDs, names, and descriptions

Refreshing Building Blocks

If your custom blocks don't appear in the Building Blocks window:

• Go to Meta > Building Blocks > Refresh Building Blocks
• This will force a refresh of the Building Blocks registry

Using Custom Building Blocks

Once created and configured, your custom Building Blocks will automatically appear in the Meta XR SDK Building Blocks window:

• Open the Building Blocks window (usually accessible from the Meta XR SDK status menu)
• Your custom blocks will be displayed alongside Meta's official blocks
• Click on a block to install it into your scene

How It Works

1. BlockData Assets: Each Building Block is represented by a CustomBlockData ScriptableObject asset. When created via the context menu, the asset is created in the currently selected folder. When created programmatically via CustomBlockDataCreator, blocks are stored in Assets/Tools/BuildingBlocks/BlockData/ by default (created automatically if needed).

2. Prefab Setup: When using the CustomBlockDataCreator API (available in code), the system automatically:

   • Adds a BuildingBlock component to your prefab
   • Sets the blockId to link the prefab to its BlockData
   • Handles prefab naming (removes [BuildingBlock] prefix if present)

3. Automatic Discovery: The CustomBlockDataInjector system automatically discovers all CustomBlockData assets in your project and injects them into the Meta XR SDK Building Blocks registry.

4. Tag Validation: The TagValidationService validates tags against Meta SDK's valid tag names. Invalid tags (including "Internal", "Hidden", and unrecognized tags) are automatically removed from blocks.

UIToolkit Block

This package includes UIToolkit integration with:

• UIToolkit Building Block (prefab and asset)
• Various UIToolkit interaction scripts for XR input
• Sample scenes demonstrating UIToolkit usage

See the UIToolkit folder for more details and examples.

Subscribing to Input Events

To subscribe to button clicks and other interactive element events in UI Toolkit, use the standard UI Toolkit event system:

// Get reference to your button
var root = uiDocument.rootVisualElement;
var button = root.Q<Button>("MyButton");

// Subscribe to click event (Method 1 - recommended)
button.clicked += OnButtonClicked;

// Or use RegisterCallback (Method 2)
button.RegisterCallback<ClickEvent>(OnButtonClickedEvent);

// Handler methods
private void OnButtonClicked()
{
    Debug.Log("Button clicked!");
}

private void OnButtonClickedEvent(ClickEvent evt)
{
    Debug.Log($"Button clicked at position {evt.position}");
}

// Don't forget to unsubscribe!
private void OnDisable()
{
    button.clicked -= OnButtonClicked;
    button.UnregisterCallback<ClickEvent>(OnButtonClickedEvent);
}