Loom UI

LoomUI is the single component you add to a startup-scene GameObject. On Awake it:

1. Builds the LoomView and input capture used by the URP renderer and keeps them alive across scene loads.
2. Initializes the Loom runtime.
3. In the Editor: spawns the Vite dev server and navigates the WebView once it’s ready.
4. In player builds: loads the static UI from Application.streamingAssetsPath/Loom/index.html.

Adding it to your scene

The quickest path is the menu:

Loom → Setup UI in Current Scene

This adds a single Loom UI GameObject and installs LoomRendererFeature on every renderer used by the project’s URP quality assets. Running the command again is safe. It keeps an existing LoomUI component and installs any missing renderer features.

If you add LoomUI manually, run the setup menu afterward. It detects the existing component and configures the URP renderers without adding another one.

Your bridge class

Your [Bridge] class must inherit LoomBridgeBase. The source generator requires this; it errors on classes that don’t:

using Loom;

[Bridge]
public partial class UIBridge : LoomBridgeBase {
  public int Score { get; set; }                         // public property → state
  [BridgeAction] public void AddPoint() { Score += 1; }  // tagged method   → action
}

The class must also be partial so the generator can add its registration logic alongside your members. public properties are state and public Event<T> properties are events by convention; a method is an action only when tagged [BridgeAction].

Accessing the bridge from gameplay code

The generator emits a static Instance property on your bridge class. Use it from anywhere in your game:

UIBridge.Instance.Score = 10;

Inspector fields

Per-scene drivers

LoomUI persists for the game’s lifetime. Per-scene GameObjects can drive scene-specific bridge state by accessing UIBridge.Instance directly:

public class GameplayLoomDriver : MonoBehaviour {
  private void Start() {
    UIBridge.Instance.CurrentScreen = SampleScreen.Hud;
  }
}

Drivers attach to scene-specific GameObjects and clean up automatically on scene unload. No cross-reference to a bootstrap singleton needed.

Editor vs player

In the Editor, Loom auto-spawns Vite and navigates the UI for you once the dev server is ready. No extra setup needed.

In player builds, the UI is loaded from Application.streamingAssetsPath/Loom/index.html, which your last production UI build wrote. See Player builds.

Shutdown

LoomUI calls LoomRuntime.Shutdown() automatically when the component is destroyed (e.g. when the application quits). No manual teardown is needed. To also stop the Vite dev server mid-session, use Loom → Stop Dev Server.