Quick answer: Unreal Niagara cross-emitter event not firing? Source emitter must generate the event in its Spawn or Update; receiver emitter must have an Event Handler listening for that source.
An impact emitter should listen to events from a projectile emitter on hit. The receiver’s Event Handler runs but no events arrive.
Source Generates Event
In the source emitter, add a Generate Location Event module. Choose event name; payload fields auto-include position / velocity.
Receiver Listens to Same Name
In the receiver emitter, Add Event Handler → Source: SourceEmitter, Event: matching-name. Names case-sensitive.
Cross-Emitter Within System
Events stay within the Niagara System. To cross systems, use Niagara Data Channels (newer API) or convert to actor messages.
Execution Order
Source must execute before receiver. Niagara orders emitters in the system — reorder if events fire after the consumer ticked.
Verifying
Source events fire and trigger receiver spawn / update logic. Visible effects on impact correlate with projectile events.
“Cross-emitter events need source generate + receiver handler with matching name and order.”
Build a small system with a probe receiver that logs every event received — debug template you can drop into any new VFX project.