Using Collision without Update Age will prevent any particles from spawning. In Collision Query and Response DataInstance.Alive has a default value of false. If no other module sets DataInstance.Alive to true, this default value will be used, and cause all particles to be killed immediately.

Set DataInstance.Alive to true directly in the stack.

Steps to Reproduce
  1. Create a new Niagara System based off the the Fountain template
  2. Add a Collision module to the Particle Update
  3. Disable the Update Age module

The emitter no longer has any particles. Re-enabling Update Age will start spawning particles again.

Have Comments or More Details?

There's no existing public thread on this issue, so head over toAnswerHub just mention UE-88914 in the post.

Login to Vote

ComponentRendering - Niagara
Affects Versions4.24
Target Fix4.25
Fix Commit12350700
Release Commit12345953
CreatedFeb 17, 2020
ResolvedMar 20, 2020
UpdatedMar 23, 2020