---
title: SCNParticleBirthDirection.constant
framework: scenekit
role: symbol
role_heading: Case
path: scenekit/scnparticlebirthdirection/constant
---

# SCNParticleBirthDirection.constant

The emitting direction is the same for all particles.

## Declaration

```swift
case constant
```

## Discussion

Discussion When using this mode, the emittingDirection property determines the base direction for all particles, and the spreadingAngle property adds random variation to this direction.

## See Also

### Constants

- [SCNParticleBirthDirection.surfaceNormal](scenekit/scnparticlebirthdirection/surfacenormal.md)
- [SCNParticleBirthDirection.random](scenekit/scnparticlebirthdirection/random.md)