# init(source:name:bindTarget:blendLayer:repeatMode:fillMode:trimStart:trimEnd:trimDuration:offset:delay:speed:) Creates a variation of the given animation by overriding its properties. ``` init(source: any AnimationDefinition, name: String = "", bindTarget: BindTarget? = nil, blendLayer: Int32 = 0, repeatMode: AnimationRepeatMode = .none, fillMode: AnimationFillMode = [], trimStart: TimeInterval? = nil, trimEnd: TimeInterval? = nil, trimDuration: TimeInterval? = nil, offset: TimeInterval = 0, delay: TimeInterval = 0, speed: Float = 1.0) ``` ## Parameters `source` The original animation that this structure modifies. `name` A textual name for the animation. `bindTarget` A textual name that identifies the animated property. `blendLayer` The order in which the framework visually composites the animation among other running animations. `repeatMode` An option that determines how the animation repeats outside the length of the view. `fillMode` The behavior when the animated property reaches its end value. `trimStart` The optional time, in seconds, at which the source animation plays. `trimEnd` The optional time, in seconds, at which the source animation stops. `trimDuration` An optional duration that overrides the calculated duration. `offset` The time, in seconds, at which the animation begins within the duration. `delay` An amount of time that lapses before the animation plays. `speed` A factor that increases or decreases the animation’s playback rate. --- 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)