---
title: velocities
framework: realitykit
role: symbol
role_heading: Instance Property
path: realitykit/forceeffectparameters/velocities
---

# velocities

The velocities of all rigid bodies under the influence of the effect, or nil if velocity information was not requested.

## Declaration

```swift
let velocities: UnsafeForceEffectBuffer<SIMD3<Float>>?
```