# element A set of nodes for reading and writing the current element within a particle simulation. ## Topics ### Functions [`float element::age()`](/documentation/ComputeGraph/element/age) Returns the current age of the element in seconds. [`float element::ageOverLifetime()`](/documentation/ComputeGraph/element/ageOverLifetime) Returns the normalized age of the element as a ratio of its lifetime. [`half4 element::color()`](/documentation/ComputeGraph/element/color) Returns the current color of the element. [`uint element::index()`](/documentation/ComputeGraph/element/index) Returns the index of the current element. [`float element::lifetime()`](/documentation/ComputeGraph/element/lifetime) Returns the total lifetime of the element in seconds. [`float3 element::position()`](/documentation/ComputeGraph/element/position) Returns the current position of the element, in the graph’s coordinate space. [`float2 element::size()`](/documentation/ComputeGraph/element/size) Returns the current size of the element. [`void element::terminate(terminate)`](/documentation/ComputeGraph/element/terminate) Ends the lifetime of the current element, if terminate is true. [`float3 element::velocity()`](/documentation/ComputeGraph/element/velocity) Returns the current velocity of the element. --- 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)