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# position

The position of the light in world coordinates.

```
var position: GLKVector4 { get set }
```

## Discussion

If the `w` component of the position is `0.0`, the light is calculated using the directional light formula. The `x`, `y`, and `z` components of the vector specify the direction the light shines. The light is assumed to be infinitely far away; attenuation and spotlight properties are ignored.

If the `w` component of the position is a non-zero value, the coordinates specify the position of the light in homogenous coordinates, and the light is either calculated as a point light or a spotlight, depending on the value of the [`spotCutoff`](/documentation/GLKit/GLKEffectPropertyLight/spotCutoff) property.

The default value is `[0.0, 0.0, 1.0, 0.0]`.

---

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