DOCS: DOCATT-8754: Updated TrackedDevice class documentation (#2298)

Co-authored-by: Chris Massie <67029035+chris-massie@users.noreply.github.com>

Author: unitALG

Packages/com.unity.inputsystem/Documentation~/projectMetadata.json

@@ -1,3 +1,7 @@
 {
-    "hideGlobalNamespace": true
+    "hideGlobalNamespace": true,
+    "xref": [
+        "com.unity.xr.openxr",
+        "com.unity.xr.interaction.toolkit"
+    ]
 }

Packages/com.unity.inputsystem/InputSystem/Devices/TrackedDevice.cs

@@ -7,17 +7,81 @@ namespace UnityEngine.InputSystem
     /// <summary>
     /// An input device that has its orientation and position in space tracked.
     /// </summary>
+    /// <remarks>
+    /// These values are typically read from input actions and fed into the
+    /// [Tracked Pose Driver](xref:input-system-tracked-input-devices#tracked-pose-driver)
+    /// component rather than being read directly from this class.
+    ///
+    /// Refer to the [Starter Assets](xref:xri-samples-starter-assets)
+    /// sample in the XR Interaction Toolkit package for a Demo Scene with an XR rig
+    /// hierarchy that uses these concepts.
+    /// </remarks>
     /// <seealso cref="UnityEngine.InputSystem.XR.XRController"/>
     /// <seealso cref="UnityEngine.InputSystem.XR.XRHMD"/>
+    /// <seealso href="https://docs.unity3d.com/Packages/com.unity.xr.openxr@latest/index.html?subfolder=/api/UnityEngine.XR.OpenXR.Input.Pose.html">UnityEngine.XR.OpenXR.Input.Pose</seealso>
     [InputControlLayout(displayName = "Tracked Device", isGenericTypeOfDevice = true)]
     public class TrackedDevice : InputDevice
     {
+        /// <summary>
+        /// Indicates which of the tracked pose components are valid by using an integer containing a
+        /// bitwise OR of the [Unity XR module enum values](https://docs.unity3d.com/ScriptReference/XR.InputTrackingState.html),
+        /// for example `InputTrackingState.Position | InputTrackingState.Rotation`.
+        /// </summary>
+        /// <remarks>
+        /// This property determines whether you can retrieve valid values from the
+        /// <see cref="devicePosition"/> and the <see cref="deviceRotation"/> properties:
+        /// - The Position bit must be set for the <see cref="devicePosition"/> property to have a valid Vector3 value.
+        /// - The Rotation bit must be set for the <see cref="deviceRotation"/> property to have a valid Quaternion.
+        /// </remarks>
         [InputControl(synthetic = true)]
         public IntegerControl trackingState { get; protected set; }
+
+        /// <summary>
+        /// Indicates whether the input device is actively tracked (1) or not (0).
+        /// </summary>
+        /// <remarks>
+        /// For more information about how OpenXR represents inferred position vs. actual position, refer to
+        /// [Reference Spaces](https://registry.khronos.org/OpenXR/specs/1.1/html/xrspec.html#spaces-reference-spaces)
+        /// (OpenXR Specification).
+        /// </remarks>
         [InputControl(synthetic = true)]
         public ButtonControl isTracked { get; protected set; }
+
+        /// <summary>
+        /// Represents the position portion of the input device's primary
+        /// [pose](xref:input-system-tracked-input-devices#tracked-pose-driver). For an HMD
+        /// device, this means the "center" eye pose. For XR controllers, it means the "grip" pose.
+        /// </summary>
+        /// <remarks>
+        /// For more information about how OpenXR represents the grip pose, refer to
+        /// [Standard pose identifiers](https://registry.khronos.org/OpenXR/specs/1.1/html/xrspec.html#semantic-paths-standard-identifiers)
+        /// (OpenXR Specification).
+        ///
+        /// > [!NOTE]
+        /// > The position value is in the tracking space reported by the device, which doesn't match
+        /// > Unity world space. Using a combination of the XR Origin component with the
+        /// > [Tracked Pose Driver](xref:input-system-tracked-input-devices#tracked-pose-driver) component
+        /// > to manage that conversion automatically is more reliable than managing it through scripting.
+        /// </remarks>
         [InputControl(noisy = true, dontReset = true)]
         public Vector3Control devicePosition { get; protected set; }
+
+        /// <summary>
+        /// Represents the rotation portion of the input device's primary
+        /// [pose](xref:openxr-input#pose-data). For an HMD
+        /// device, this means the "center" eye pose. For XR controllers, it means the "grip" pose.
+        /// </summary>
+        /// <remarks>
+        /// For more information about how OpenXR represents the grip pose, refer to
+        /// [Standard pose identifiers](https://registry.khronos.org/OpenXR/specs/1.1/html/xrspec.html#semantic-paths-standard-identifiers)
+        /// (OpenXR Specification).
+        ///
+        /// > [!NOTE]
+        /// > The rotation value is in the tracking space reported by the device, which doesn't match
+        /// > Unity world space. Using a combination of the XR Origin component with the
+        /// > [Tracked Pose Driver](xref:input-system-tracked-input-devices#tracked-pose-driver) component
+        /// > to manage that conversion automatically is more reliable than managing it through scripting.
+        /// </remarks>
         [InputControl(noisy = true, dontReset = true)]
         public QuaternionControl deviceRotation { get; protected set; }