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

# particleMass

The mass, in kilograms, of each particle in the system. Animatable.

## Declaration

```swift
var particleMass: CGFloat { get set }
```

## Discussion

Discussion A particle’s mass determines its resistance to forces. The effects of the dampingFactor property and any SCNPhysicsField objects affecting each particle are proportional to its mass. You can randomize the masses of particles in the system with the particleMassVariation property. The default value is 1.0 kilograms. 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)
- [acceleration](scenekit/scnparticlesystem/acceleration.md)
- [dampingFactor](scenekit/scnparticlesystem/dampingfactor.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)