# convertToAdditiveUsingFirstSample() Converts animation to additive format by subtracting the first frame. ``` static func convertToAdditiveUsingFirstSample() -> SampledAnimation.SkeletalAnimationOperation ``` ## Return Value A [`SampledAnimation.SkeletalAnimationOperation`](/documentation/RealityKit/SampledAnimation/SkeletalAnimationOperation) that, when processed, produces a `SampledAnimation` in additive format. ## Discussion Creates a delta animation that represents the difference between each frame and the animation’s first frame. Useful for creating relative motion from absolute animation. --- 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)