---
title: size
framework: Compute Graph
role: symbol
role_heading: Instance Property
platforms: [iOS 27.0+, iPadOS 27.0+, Mac Catalyst 27.0+, macOS 27.0+, tvOS 27.0+, visionOS 27.0+]
path: computegraph/elementspawnparameters/size
---

# size

The initial size of the particle as a 2D vector representing width and height.

## Declaration

```swift
var size: SIMD2<Float> { get set }
```

## Discussion

Discussion For most particle systems, this represents the billboard size in world space units. x component: width of the particle y component: height of the particle Equal values create square particles, while different values create rectangular particles.