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# bytesPerIndex

The number of bytes that represent each index value in the element’s data.

```
var bytesPerIndex: Int { get }
```

## Discussion

An element’s [`data`](/documentation/SceneKit/SCNGeometryElement/data) property holds an array of index values identifying vertices in a geometry source. SceneKit interprets the data as an array of unsigned integers, whose size is specified by the [`bytesPerIndex`](/documentation/SceneKit/SCNGeometryElement/bytesPerIndex) property.

---

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