How can I spawn a single particle in Niagara upon input?

[Chatouille]

So I’m noob with niagara but I think I got it working.

1. Make a basic niagara ribbon emitter, and remove spawn modules

2. Add user exposed parameter “SpawnCounter” int32

3. Add emitter attributes “SpawnCounter” and “UserSpawnCounter” int32

4. Create new scratch module in EmitterUpdate section. I copied the output node from SpawnRate module, and fiddled the following :

5. For some reason the scratch pad cannot access user parameters, so that’s why we use UserSpawnRate at emitter level. Add a generic set module before scratch pad to retrieve the parameter :

6. Add particle system to character

7. Update user exposed parameter from BP