# Utility extensions static class extension helpers This page groups the SDK's broadly-used helper types: the `Extensions` static class (identification, camera-info accessors, Core↔Unity math conversion, logging) and four standalone utilities — `ObjectFieldExtensions`, `TextureExtensions`, `AnimationTimer`, and `BiDictionary`. :::note[Units] All spatial conversions on this page are in **meters** (Unity world-space). The `ToUnity`/`ToCore` helpers convert between AR 51 `Core` math types and Unity types without rescaling — both sides are meters. ::: ## Extensions static class ```csharp public static class Extensions ``` **Namespace:** `AR51.Unity.SDK` The SDK's broadly-used extension helpers. This page documents the members app developers call: skeleton identification, camera-info accessors, `Core`↔Unity math conversion, and logging. Array/marshalling helpers (`ToArray`, `ToVector3`, `ToMatrix4x4`, `ToVector3Array`, `ToMatrix4x4Array`, `EfficientReverse`, `ReadExact`, …) are also public but are low-level transport plumbing. ### IsIdentified ```csharp public static bool IsIdentified(this SkeletonReply skeletonReply); ``` Returns `true` when the skeleton has been matched to a known entity — i.e. its `EntityId` is non-null, non-empty, and not `"-1"`. Use it to filter to recognized people; [`SkeletonConsumer`](/docs/sdk-api/unity-api/classes/skeletonconsumer)'s `IgnoreUnidentified` uses this internally. `true` if the skeleton is matched to a known entity ```csharp // Only react to recognized people if (skeletonReply.IsIdentified()) DoSomethingWith(skeletonReply.EntityId); ``` ### GetEndpoint ```csharp public static string GetEndpoint(this ComponentDescriptor c); ``` Formats a component descriptor's address as `"ip:port"` — the string form the services connect with. the endpoint as `"ip:port"` ### Camera-info accessors ```csharp public static Matrix4x4 GetIntrisic(this CvsCameraInfo info); // intrinsic 4x4 public static Matrix4x4 GetExtrinsic(this CvsCameraInfo info); // extrinsic (world pose), handedness-corrected public static float GetVerticalFOV(this CvsCameraInfo info); // degrees public static float GetHorizontalFOV(this CvsCameraInfo info);// degrees ``` Derive the usable camera matrices and field-of-view from a [`CvsCameraInfo`](/docs/sdk-api/unity-api/classes/camerafeedclient). `GetExtrinsic` returns the camera's world pose with handedness already corrected for Unity; the FOV accessors return **degrees**. ### Core ↔ Unity conversion ```csharp // Core → Unity (positions in meters) public static Vector3 ToUnity(this AR51.Mocap.Filters.Double3 v); // meters, double→float public static Color ToUnity(this Core.Color color); public static Vector2 ToUnity(this Core.Vector2 v); public static Vector3 ToUnity(this Core.Vector3 v); public static Quaternion ToUnity(this Core.Quaternion v); public static Bounds ToUnity(this Bound2D bounds); // Unity → Core public static Core.Color ToCore(this Color c); public static Core.Vector2 ToCore(this Vector2 v); public static Core.Vector3 ToCore(this Vector3 v); public static Core.Vector4 ToCore(this Vector4 v); public static Core.Quaternion ToCore(this Quaternion q); // Color helpers public static Color Parse(this Color _, string colorName); // named CSS-ish colors → Color (Color.clear if unknown) public static Color FromUInt(this Color _, uint hex); // 0xAARRGGBB → Color ``` Convert between AR 51 `Core` math types and Unity types. Positions are in **meters** on both sides — no rescaling is applied. `Parse` maps a named color (returning `Color.clear` if the name is unknown); `FromUInt` builds a color from a packed `0xAARRGGBB` value. ```csharp // Core mocap position → Unity world-space (meters) Vector3 wrist = coreWrist.ToUnity(); // Packed hex → Color Color accent = default(Color).FromUInt(0xFF33AAFF); // ARGB ``` ### Log / LogWarning / LogError ```csharp public static void Log(this object sender, string msg, /* [Caller*] */ ...); public static void LogWarning(this object sender, string msg, ...); public static void LogError(this object sender, string msg, ...); public static void Log(this MonoBehaviour sender, string msg, ...); ``` Context-aware logging extensions. They auto-prefix each message with `File.Method[line]` (captured via `[Caller*]` attributes) — prefer them over hand-written context strings. Available on any `object` (and a `MonoBehaviour` overload). ```csharp this.Log("connected"); // → "MyBehaviour.Start[42] connected" this.LogError("stream dropped"); ``` ## ObjectFieldExtensions static class ```csharp public static class ObjectFieldExtensions ``` **Namespace:** `AR51.Unity.SDK` Reflection get/set of a field **or** property by name. Includes non-public members by default (`DefaultFlags = BindingFlags.NonPublic | BindingFlags.Public`). ```csharp public const BindingFlags DefaultFlags = BindingFlags.NonPublic | BindingFlags.Public; public static T GetValue(this object owner, string fieldName, BindingFlags flags = DefaultFlags); public static void SetValue(this object owner, string fieldName, object value, BindingFlags flags = DefaultFlags); ``` ⚠️ `GetValue` returns `default(T)` if the member isn't found (no exception); `SetValue` logs a warning on failure. Reflection-based access is for advanced/interop scenarios — prefer the typed API where one exists. ```csharp // Read a private field by name float smoothing = consumer.GetValue("_smoothingFactor"); consumer.SetValue("_smoothingFactor", 0.9f); ``` ## TextureExtensions static class ```csharp public static class TextureExtensions ``` **Namespace:** `AR51.Unity.SDK` GPU-assisted texture resampling and JPG encoding. ```csharp public static Texture2D Resample(this Texture source, int width, int height, TextureFormat textureFormat = TextureFormat.RGBA32, bool mipChain = true, bool linear = false); public static Texture2D ResampleTo(this Texture source, Texture2D target, RenderTexture renderTexture = null); public static byte[] EncodeToJPG(this Texture source, ref Texture2D target, int width, int height, int quality = 70); ``` `width`/`height` are in **pixels**; `quality` is **0–100** (default `70`). `Resample` returns a new `Texture2D`; `ResampleTo` blits into an existing `target`. `EncodeToJPG` resizes (clamped to the source dimensions) into `target` and returns the JPG bytes. ```csharp // Resize a camera frame and encode at quality 85 Texture2D thumb = null; byte[] jpg = cameraFrame.EncodeToJPG(ref thumb, 640, 360, quality: 85); ``` ## AnimationTimer class ```csharp public class AnimationTimer ``` **Namespace:** `AR51.Unity.SDK` A lightweight fixed-duration timer driven by `Time.time`. Construct it with a duration in seconds, then poll `Factor`/`SmoothFactor` each frame to drive an animation.
| Member | Type | Description | |---|---|---| | `StartTime` | `float` | capture time when the timer was created (seconds), read-only | | `Duration` | `float` | configured duration in **seconds**, read-only | | `ElapsedTime` | `float` | seconds since `StartTime` | | `Factor` | `float` | linear progress, **0–1** | | `SmoothFactor` | `float` | smoothstep progress, **0–1** | | `IsRunning` | `bool` | `true` while `ElapsedTime < Duration` |
```csharp public AnimationTimer(float duration); // duration in seconds ``` ```csharp var fade = new AnimationTimer(0.5f); // half-second fade // ...each frame: material.color = Color.Lerp(from, to, fade.SmoothFactor); if (!fade.IsRunning) { /* done */ } ``` ## BiDictionary<T1,T2> BiDictionary<T1,T2> global namespace ```csharp public class BiDictionary : IDictionary ``` **Namespace:** *global* (no namespace) A bidirectional dictionary: look up by key in **either** direction. Implements `IDictionary` plus mirrored overloads keyed by `T2`. Both the key and the value must be unique — each side is a real dictionary. ```csharp public T2 this[T1 key] { get; set; } public T1 this[T2 key] { get; set; } public void Add(T1 key, T2 value); // (+ T2 / KeyValuePair overloads, both directions) public bool ContainsKey(T1 key); public bool ContainsKey(T2 key); public bool TryGetValue(T1 key, out T2 value); public bool TryGetValue(T2 key, out T1 value); public bool Remove(T1 key); public bool Remove(T2 key); public ICollection Keys { get; } public ICollection Values { get; } public int Count { get; } public bool IsReadOnly { get; } public void Clear(); ``` ⚠️ Because both sides are unique dictionaries, `T1` and `T2` should be distinct types — otherwise the overloads keyed by `T1` vs `T2` are ambiguous to the compiler. ```csharp var map = new BiDictionary(); map.Add("alice", 1); int id = map["alice"]; // forward string n = map[1]; // reverse ``` ## See also - [`SkeletonConsumer`](/docs/sdk-api/unity-api/classes/skeletonconsumer) — uses `IsIdentified` internally for `IgnoreUnidentified` - [`CameraFeedClient`](/docs/sdk-api/unity-api/classes/camerafeedclient) — owns the `CvsCameraInfo` the camera accessors read from - [`ServiceManager`](/docs/sdk-api/unity-api/classes/servicemanager) — resolves the `ComponentDescriptor` whose endpoint `GetEndpoint` formats - [Recording & playback](/docs/sdk-api/unity-api/classes/recording-playback) — keyframe utilities in the same area - [Class index](/docs/sdk-api/unity-api/classes) — all Unity SDK types