# GroupAction An action that runs a list of other actions. ## Discussion This action defines how the runtime executes each action in the [actions](/documentation/USD/actions) array. When [type](/documentation/USD/type) is `serial`, the runtime performs [actions](/documentation/USD/actions) one after the other. When [type](/documentation/USD/type) is `concurrent`, the runtime starts each action at the same time. When this action’s [type](/documentation/USD/type) is `serial`, you can specify a delay between two actions by placing a `WaitAction` between them. ### Declaration ```other class Preliminary_Action "GroupAction" ``` ### Create a sequential or looping group action The following example defines a group of actions that run sequentially. The group contains a flip action, a wait action, and a hide action. ```other def Preliminary_Action "SimpleGroup" ( inherits = ) { rel actions = [ , , ] uniform bool loops = false uniform uint performCount = 1 def Action "Flip" ( inherits = ) { uniform token motionType = "flip" } def Action "Wait" ( inherits = ) { } def Action "Hide" ( inherits = ) { uniform token type = "hide" } } ``` The following group named `EndlessLoop` repeats a set of actions indefinitely because `performCount` is `0`. ```swift def Action "EndlessLoop" ( inherits = ) { rel actions = [...] uniform bool loops = true uniform uint performCount = 0 } ``` ## Topics ### Properties [info:id](/documentation/USD/info-id) The action’s unique identifier. [type](/documentation/USD/type) An option that controls the order in which the actions execute. [loops](/documentation/USD/loops) A Boolean value indicating whether the group loops. [performCount](/documentation/USD/performcount) A value that specifies the number of times the group’s actions repeat. [actions](/documentation/USD/actions) A list of actions that make up the group. --- 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)