Multiple Niagara emitters driving one Fluid Sim


I have an issue that I cannot seem to get my head around, and I would have thought this is doable, but I cannot figure it out.

I have 4 separate Niagara emitters doing different things at different times on different parts of a skeletal mesh, I want to use all of them as a source for one 2D Fluid sim inside Niagara, the final effect should look like the fluid sim is emitting at different locations across the mesh, driven by these four niagara emitters.

But it seems that only one emitter is ever driving the fluid sim? I have tried doing things like reading all four emitters into one system and spawning that way and making that emitter the single driving fluid source, but you can’t read from multiple attributes (according to the Niagara tool tip)

In my screengrab, only the emitter that is ringed is driving 2D Fluid Emitter, but I want all of them to drive it.

Any help would much appreciated

Thank you!

Ok so you can’t have multiple sources driving a 2D Fluid, it will only let you have one source emitter…

Is there a way I can do this without having to have four fluid emitters, feels a bit inflexible and incredibly inefficient, not to be able to do this, I would have thought many instances would call for this sort of thing?

imo you should merge them into one emitter with different spawngroups, as you can see here those are variables that u need to modify to drive fluid sim, as long as you put different values here it will affect fluid sim in different way.
If you dont use some parameters u can look them up in fluid sim emitter itself and try to deactivate them (in material aswell) to further optimize fluid sim, for example I didnt need lightingsim etc, and those are only variables that are send to material

Thank you :slight_smile:

I did look into spawn groups, but I don’t think they will won’t work in this situation, I’m using Sample Texture for our character masks, it has to be done this way too for our setup, and spawn groups do not seem to be an option in this instance.

Thank you

What I have done (which feels a bit hacky), is to create different systems for different parts and just spawn them at the relevant time, it does mean that I will have two fluid sims happening at once most of the time, but feels like a better option than having 4 on that are not being used.

I’m not comfortable with the setup, but due to time constraints vs my limited scratch pad knowledge, it feels like my only reluctant option.