API Reference > imodeljs-frontend > Rendering > ParticleProps > size size size: number | Readonly<WritableXAndY> The size of the particle, in the collection's coordinate space. If omitted, it defaults to the size supplied to the collection by ParticleCollectionBuilderParams.size. Supplying a number produces a square; supplying a non-uniform XAndY produces a rectangle. Must be positive. Defined in core/frontend/src/render/ParticleCollectionBuilder.ts Line 65 Last Updated: 11 June, 2024