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# sourcePosition(at:)

Returns the source position of a vertex.

```
func sourcePosition(at index: Int) -> vector_float2
```

## Parameters

`index`

The index of the position vertex to query.

## Return Value

The normalized position of the specified vertex in `sourcePositions`.

## Discussion

The specified index must be between 0 and the warp geometry grid’s [`vertexCount`](/documentation/SpriteKit/SKWarpGeometryGrid/vertexCount) `- 1`.

---

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