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# isDoubleSided

A Boolean value that determines whether SceneKit renders both front and back faces of a surface.

```
var isDoubleSided: Bool { get set }
```

## Discussion

Polygons in a SceneKit mesh are, by default, single-sided. Each one contain a *normal vector*, which identifies the side of the polygon that’s the visible side. SceneKit uses that normal vector to determine which polygons are *front faces* that point toward the camera, and which are *back faces* that point away from it. When `doubleSided` is <doc://com.apple.documentation/documentation/Swift/false> (the default value), SceneKit only renders front faces to improve performance.

If you change this property’s value to <doc://com.apple.documentation/documentation/Swift/true>, SceneKit renders both the front and back surfaces of every polygon.

You can animate changes to this property’s value. See [Animating SceneKit Content](/documentation/SceneKit/animating-scenekit-content). Animating this property fades between the results of rendering with each state.

---

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