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Triggering Events

In the Unreal runtime, “events” should be modeled as ViewModel Trigger Properties. Fire and observe triggers through the ViewModel Instance.
Use Trigger Properties for one-shot actions (clicks, milestones, transitions).
  1. Define a Trigger Property in your Rive ViewModel (for example OnClick).
  2. In Unreal, create and bind a ViewModel Instance to your Rive widget or artboard.
  3. Fire the trigger from Blueprint using Call .
  4. Respond to the trigger in Blueprint using Bind Event to .

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Blueprint Setup

  1. Create a Rive widget from your imported .riv file.
  2. Create a ViewModel Instance using Make View Model.
  3. Assign that instance to the widget/artboard.
  4. Keep a reference to the bound ViewModel instance.
Keep ViewModel creation and delegate binding in the same owning Blueprint so lifetime is clear.

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Firing a Trigger in Blueprint

When you want to fire an event (button press, gameplay action, etc.), call the trigger function exposed on the bound ViewModel instance. Typical pattern:
  1. Get your bound ViewModel instance reference.
  2. Call Call (for example Call OnClick).
  3. Pass any required inputs for the generated function signature.
The trigger is consumed during the next artboard tick and resets automatically. In the following image, the trigger “loaded” is being fired from Blueprint:
Firing a trigger from Blueprint

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Observing Trigger Results

If Unreal needs to react when the trigger is fired:
  • Use Bind Event to on the ViewModel instance.
  • Handle callbacks synchronously during the update cycle.
  • Unbind delegates before destroying the ViewModel instance.
In the following image, a custom event is bound to the trigger “loaded”:
Binding a trigger in Blueprint