Quick answer: Unreal Niagara event-handling system causing game thread spikes? Event execution runs on game thread by default - dispatch heavy work to worker threads.
Hit-VFX with 50+ collisions per second spikes the game thread. Profiler: Niagara event execution at the top.
Move work to workers
Niagara event handler should be lightweight. Heavy game logic posts to a task; game thread continues.
Reduce event rate
Filter events at source. One impact event per 100ms even if 50 particles collide. Visual fidelity preserved; cost dropped.
Profile event handlers
UE5 Insights' Niagara track. Per-event execution time visible; outliers diagnose the bottleneck.
“Events are gateways for gameplay code. Heavy gameplay in events blocks frames.”
Establish 'events post tasks; don't run them' as a rule. The game thread stays responsive.