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# SCNParticleBirthDirection

Options for the initial direction of each emitted particle, used by the [`birthDirection`](/documentation/SceneKit/SCNParticleSystem/birthDirection) property.

```
enum SCNParticleBirthDirection
```

## Topics

### Constants

[`SCNParticleBirthDirectionConstant`](/documentation/SceneKit/SCNParticleBirthDirection/constant)

The emitting direction is the same for all particles.

[`SCNParticleBirthDirectionSurfaceNormal`](/documentation/SceneKit/SCNParticleBirthDirection/surfaceNormal)

The emitting direction for each particle is along the surface normal vector at the point where the particle is emitted.

[`SCNParticleBirthDirectionRandom`](/documentation/SceneKit/SCNParticleBirthDirection/random)

SceneKit randomizes the emitting direction for each particle.

## Relationships

### Conforms To

[`Equatable`](/documentation/Swift/Equatable)

[`Hashable`](/documentation/Swift/Hashable)

[`SendableMetatype`](/documentation/Swift/SendableMetatype)

[`BitwiseCopyable`](/documentation/Swift/BitwiseCopyable)

[`Sendable`](/documentation/Swift/Sendable)

[`RawRepresentable`](/documentation/Swift/RawRepresentable)

---

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