---
title: Preliminary_Trigger
framework: usd
role: collectionGroup
path: usd/preliminary-trigger
---

# Preliminary_Trigger

A condition that, when met, performs an action.

## Overview

Overview Because it inherits Typed, this schema declares a Preliminary_Trigger as a type of prim. For more information about typed schemas, see USD Specification > Typed. The runtime executes triggers based on: User input, like a user’s tap gesture. Scene state, including a prim’s proximity to the user’s device. Programmatic conditions, like application state or a function result. Declaration class "Preliminary_Trigger" (     inherits = </Typed> ) Add a tap trigger to a cube The following example shows how a prim named TapCube opts in to notification of user taps. #usda 1.0

def Cube "Cube" {}

def Preliminary_Trigger "TapCube" {     uniform token info:id = "TapGesture"     rel affectedObjects = [ </Cube> ] }

## Topics

### Properties

- [info:id](usd/info-id.md)

## See Also

### Triggers

- [CollideTrigger](usd/collidetrigger.md)
- [ProximityToCameraTrigger](usd/proximitytocameratrigger.md)
- [SceneTransitionTrigger](usd/scenetransitiontrigger.md)
- [TapGestureTrigger](usd/tapgesturetrigger.md)
- [NotificationTrigger](usd/notificationtrigger.md)