---
title: convertToAdditiveUsingFirstSample()
framework: realitykit
role: symbol
role_heading: Type Method
path: realitykit/sampledanimation/skeletalanimationoperation/converttoadditiveusingfirstsample()
---

# convertToAdditiveUsingFirstSample()

Converts animation to additive format by subtracting the first frame.

## Declaration

```swift
static func convertToAdditiveUsingFirstSample() -> SampledAnimation<Value>.SkeletalAnimationOperation
```

## Return Value

Return Value A SkeletalAnimationOperation that, when processed, produces a SampledAnimation<JointTransforms> in additive format.

## Discussion

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.

## See Also

### Converting to additive animation

- [convertToAdditive(baseAnimation:)](realitykit/sampledanimation/skeletalanimationoperation/converttoadditive(baseanimation:).md)
- [convertToAdditiveUsingRestPose()](realitykit/sampledanimation/skeletalanimationoperation/converttoadditiveusingrestpose().md)