# IKComponent.Joint The update stage object that lets you read and update the current settings of a single joint in an IK solver. ``` class Joint ``` ## Overview The settings this object exposes are the runtime editable values of a solver joint. Initial values are set in [`IKRig.Joint`](/documentation/RealityKit/IKRig/Joint). ## Topics ### Instance Properties [`var fkWeightPerAxis: SIMD3`](/documentation/RealityKit/IKComponent/Joint/fkWeightPerAxis) The per-axis weight of the source animation demand on the joint. [`let id: IKComponent.Joint.ID`](/documentation/RealityKit/IKComponent/Joint/id) The identifier of this joint. [`var name: String`](/documentation/RealityKit/IKComponent/Joint/name) The name of the joint. [`var rotationStiffness: SIMD3`](/documentation/RealityKit/IKComponent/Joint/rotationStiffness) The per-axis rotational stiffness of the joint. ## Relationships ### Conforms To [`Identifiable`](/documentation/Swift/Identifiable) --- 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)