---
title: boneWeights
framework: scenekit
role: symbol
role_heading: Type Property
path: scenekit/scngeometrysource/semantic-swift.struct/boneweights
---

# boneWeights

The semantic for bone weight data, used for skeletal animation of skinned surfaces.

## Declaration

```swift
static let boneWeights: SCNGeometrySource.Semantic
```

## Discussion

Discussion For a geometry source, this semantic identifies data containing skeletal animation data for each vertex in the geometry. SceneKit uses this information to determine how much a vertex’s position is influenced by the positions of bone nodes in the skeleton. For a custom shader program, you use this semantic to bind SceneKit’s bone weight data to an input attribute of the shader. For details on skeletal animation, see SCNSkinner.

## See Also

### Skeletal Animation Semantics

- [boneIndices](scenekit/scngeometrysource/semantic-swift.struct/boneindices.md)