# DockAccessory Obtain accessory information and control tracking behavior. ``` final class DockAccessory ``` ## Overview `DockAccessory` provides information about the dock accessory including its model name and firmware version. It also controls the dock accessory when you disable system tracking. Use `DockAccesory` to perform animations, or explicitly control the position of the dock accessory in three-dimensional space by supplying coordinates in units of radians. The collection of the X, Y, and Z values corresponding to pitch, yaw, and roll is the *angular position* of the dock accessory. If there are multiple subjects in a video frame, direct the dock accessory to focus on a particular area of the frame using [`setFramingMode(_:)`](/documentation/DockKit/DockAccessory/setFramingMode(_:)). > Important: DockKit throws a ``doc://com.apple.DockKit/documentation/DockKit/DockKitError/frameRateTooHigh`` exception if you animate or set the orientation of the dock accessory too quickly, so keep call rates at 2 times per second or less. ## Topics ### Selecting and tracking [`selectSubject(at:)`](/documentation/DockKit/DockAccessory/selectSubject(at:)) Selects a subject to track at the supplied coordinates. [`track(_:cameraInformation:)`](/documentation/DockKit/DockAccessory/track(_:cameraInformation:)-4yl9b) Automatically generate and send tracking vectors to the device. [`track(_:cameraInformation:)`](/documentation/DockKit/DockAccessory/track(_:cameraInformation:)-44mwn) Automatically generate and send tracking vectors to the device. [`DockAccessory.Observation`](/documentation/DockKit/DockAccessory/Observation) An observation of the contents of a single video frame. [`DockAccessory.CameraInformation`](/documentation/DockKit/DockAccessory/CameraInformation) A collection of tracking information about the camera currently in use. [`DockAccessory.CameraOrientation`](/documentation/DockKit/DockAccessory/CameraOrientation) The set of camera orientations used to extract coordinates. ### Performing animation [`animate(motion:)`](/documentation/DockKit/DockAccessory/animate(motion:)) Starts an animation sequence. [`setRegionOfInterest(_:)`](/documentation/DockKit/DockAccessory/setRegionOfInterest(_:)) Sets the area in the video frame in which the dock accessory tracks a subject. [`regionOfInterest`](/documentation/DockKit/DockAccessory/regionOfInterest) The area in the video frame in which the dock accessory tracks a subject. [`DockAccessory.Animation`](/documentation/DockKit/DockAccessory/Animation) Character animations that describe how to move the dock accessory. ### Setting position and limits [`setLimits(_:)`](/documentation/DockKit/DockAccessory/setLimits(_:)) Sets limits for the axes of rotation. [`setOrientation(_:duration:relative:)`](/documentation/DockKit/DockAccessory/setOrientation(_:duration:relative:)-2epe2) Sets the position of each axis of orientation to radians for pitch, yaw, and roll. [`setOrientation(_:duration:relative:)`](/documentation/DockKit/DockAccessory/setOrientation(_:duration:relative:)-6b0fl) Sets the position of each axis of orientation to radians for pitch, yaw, and roll. [`setAngularVelocity(_:)`](/documentation/DockKit/DockAccessory/setAngularVelocity(_:)) Sets the angular velocity of each axis of orientation. ### Setting framing mode [`setFramingMode(_:)`](/documentation/DockKit/DockAccessory/setFramingMode(_:)) Customize the dock accessory’s tracking behavior. [`framingMode`](/documentation/DockKit/DockAccessory/framingMode-swift.property) The current framing mode. [`DockAccessory.FramingMode`](/documentation/DockKit/DockAccessory/FramingMode-swift.enum) The mode to control framing of the subject when tracking. ### Getting position and limits [`motionStates`](/documentation/DockKit/DockAccessory/motionStates-swift.property) Motion information from the dock accessory that includes current orientation and velocity of all axes. [`limits`](/documentation/DockKit/DockAccessory/limits-swift.property) Current limits for the axes of rotation and maximum angular velocity. [`DockAccessory.MotionState`](/documentation/DockKit/DockAccessory/MotionState) An event that indicates the state of a dock accessory’s current position and speed. [`DockAccessory.MotionStates`](/documentation/DockKit/DockAccessory/MotionStates-swift.struct) An asynchronous sequence of orientation and velocity updates from the device. [`DockAccessory.Limits`](/documentation/DockKit/DockAccessory/Limits-swift.struct) Soft limits on multiple axes of rotation. ### Getting accessory information [`firmwareVersion`](/documentation/DockKit/DockAccessory/firmwareVersion) The firmware version of the dock accessory. [`hardwareModel`](/documentation/DockKit/DockAccessory/hardwareModel) The model of the dock accessory. [`identifier`](/documentation/DockKit/DockAccessory/identifier-swift.property) The name and unique identifer of the dock accessory. [`DockAccessory.Identifier`](/documentation/DockKit/DockAccessory/Identifier-swift.struct) Information that uniquely identifies the dock accessory. [`DockAccessory.Category`](/documentation/DockKit/DockAccessory/Category) Types of supported dock accesories. [`DockAccessory.State`](/documentation/DockKit/DockAccessory/State) The state of a dock accessory. [`DockAccessory.StateChange`](/documentation/DockKit/DockAccessory/StateChange) An event that indicates a change in the state of a dock accessory. [`DockAccessory.StateChanges`](/documentation/DockKit/DockAccessory/StateChanges) An asynchronous sequence of dock accessory state changes. ### Inspecting the object [`hash(into:)`](/documentation/DockKit/DockAccessory/hash(into:)) Creates a unique identifier representing the object. [`debugDescription`](/documentation/DockKit/DockAccessory/debugDescription) The text description of the dock accessory state. --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)