# init(from:by:mode:timing:isAdditive:) Creates a new action that interpolates from a specified starting transform towards a specified transform, which is relative to the start. Alternatively, interpolates towards the default source if `by` is not supplied. ``` init(from: Value, by: Value? = nil, mode: FromToByAction.TransformMode = .default, timing: AnimationTimingFunction = .linear, isAdditive: Bool = false) ``` ## Parameters `from` Transform set at the start of the animation. `by` Transform which is used to increment the starting transform. Used to determine the final transform we animate towards. Set this to `nil` to animate towards the defaultSource transform. `mode` Determines what space the transforms are relative to. `timing` Controls the progress of the animation. `isAdditive` Specifies whether you can additively blend the output from the action’s animation. ## Discussion `from` → `from + by` or `from` → `defaultSource` --- 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)