# ElementSpawnParameters Parameters used to configure the initial state of a particle when it’s spawned in the simulation. ``` struct ElementSpawnParameters ``` ## Overview The values specified become initial values in the Initialization stage, which can read or overwrite the values. ## Usage ```swift let params = ElementSpawnParameters( position: SIMD3(0, 1, 0), velocity: SIMD3(0, -1, 0), size: SIMD2(0.02, 0.02), color: SIMD4(1, 0.5, 0, 1), lifetime: 2.0 ) ``` ## Topics ### Initializers [`init(position: SIMD3, velocity: SIMD3, size: SIMD2, color: SIMD4, lifetime: Float)`](/documentation/ComputeGraph/ElementSpawnParameters/init(position:velocity:size:color:lifetime:)) Creates a new set of particle spawn parameters. ### Instance Properties [`var color: SIMD4`](/documentation/ComputeGraph/ElementSpawnParameters/color) The initial color and alpha (transparency) of the particle. [`var lifetime: Float`](/documentation/ComputeGraph/ElementSpawnParameters/lifetime) The initial lifetime of the particle in seconds. [`var position: SIMD3`](/documentation/ComputeGraph/ElementSpawnParameters/position) The initial 3D position of the particle in world space coordinates. [`var size: SIMD2`](/documentation/ComputeGraph/ElementSpawnParameters/size) The initial size of the particle as a 2D vector representing width and height. [`var velocity: SIMD3`](/documentation/ComputeGraph/ElementSpawnParameters/velocity) The initial velocity vector of the particle in world space units per second. ## Relationships ### Conforms To [`Sendable`](/documentation/Swift/Sendable) [`SendableMetatype`](/documentation/Swift/SendableMetatype) --- Copyright © 2026 Apple Inc. All rights reserved. | [Terms of Use](https://www.apple.com/legal/internet-services/terms/site.html) | [Privacy Policy](https://www.apple.com/privacy/privacy-policy)