[Home](./index.md) > [server](./server.md) > [ParticleEmitter](./server.particleemitter.md) > [opacityStartVariance](./server.particleemitter.opacitystartvariance.md) ## ParticleEmitter.opacityStartVariance property The opacity variance of an emitted particle at the start of its lifetime. **Signature:** ```typescript get opacityStartVariance(): number | undefined; ```