---
title: acceleration
framework: scenekit
role: symbol
role_heading: Instance Property
path: scenekit/scnparticlesystem/acceleration
---

# acceleration

The constant acceleration vector, in units per second per second, applied to all particles in the system. Animatable.

## Declaration

```swift
var acceleration: SCNVector3 { get set }
```

## Discussion

Discussion Use this property to simulate effects such as wind or gravity on particles. To use the same gravity vector that applies to physics bodies in the scene, or to apply more than one constant acceleration to particles, see the isAffectedByGravity property. The default value is SCNVector3Zero, specifying no acceleration. You can animate changes to this property’s value. See Animating SceneKit Content.

## See Also

### Simulating Physics for Particles

- [isAffectedByGravity](scenekit/scnparticlesystem/isaffectedbygravity.md)
- [isAffectedByPhysicsFields](scenekit/scnparticlesystem/isaffectedbyphysicsfields.md)
- [colliderNodes](scenekit/scnparticlesystem/collidernodes.md)
- [particleDiesOnCollision](scenekit/scnparticlesystem/particlediesoncollision.md)
- [dampingFactor](scenekit/scnparticlesystem/dampingfactor.md)
- [particleMass](scenekit/scnparticlesystem/particlemass.md)
- [particleMassVariation](scenekit/scnparticlesystem/particlemassvariation.md)
- [particleCharge](scenekit/scnparticlesystem/particlecharge.md)
- [particleChargeVariation](scenekit/scnparticlesystem/particlechargevariation.md)
- [particleBounce](scenekit/scnparticlesystem/particlebounce.md)
- [particleBounceVariation](scenekit/scnparticlesystem/particlebouncevariation.md)
- [particleFriction](scenekit/scnparticlesystem/particlefriction.md)
- [particleFrictionVariation](scenekit/scnparticlesystem/particlefrictionvariation.md)