# Recording, anchors & utilities

Secondary but public surface: recording/playback, spatial-anchor UI, scene-helper components, and utility extensions.

## Spatial anchors

### AnchorVisualization

Moved to [`Scene components & anchors`](/docs/sdk-api/unity-api/classes/scene-components).

### BoundaryVisualization

Moved to [`Scene components & anchors`](/docs/sdk-api/unity-api/classes/scene-components).

## Scene components

Moved to [`Scene components & anchors`](/docs/sdk-api/unity-api/classes/scene-components).

## Recording & playback

Moved to [`Recording & playback`](/docs/sdk-api/unity-api/classes/recording-playback).

### SkeletonWebStreamer

Moved to [`Recording & playback`](/docs/sdk-api/unity-api/classes/recording-playback).

## Utility extensions

### Extensions

Moved to [`Utility extensions`](/docs/sdk-api/unity-api/classes/extensions).

### Other helpers

Moved to [`Utility extensions`](/docs/sdk-api/unity-api/classes/extensions).

## Namespaces

- **`AR51.Unity.SDK`** — the dominant root (services, `SkeletonConsumer`, `Person`, `Joints`, `AR51Character`, `Extensions`, most types).
- **`AR51.Unity.SDK.Playback`** / **`.Recorder`** — replay / recording.
- **`AR51.Unity.SDK.Utilities`** / **`.Components`** / **`.Tracker`** — helpers, scene components, XR tracking.
- **Global namespace:** `BiDictionary<T1,T2>`, `SkeletonWebStreamer`.

:::note[Internal — not documented]
The IK/solver math (`IKSolver` and `internal` solver types behind `AR51Character`/`Person.SolveIK`), the platform fallback adapters (`EmptyHandsAdapter`, `EmptyControllerAdapter`, `DefaultBoundaryAdapter`), device-capture plumbing, `PersonIdLabelFactory`, and the gRPC/proto wire types are intentionally excluded — they're internal or proprietary.
:::