How to seek/set desired age of Niagara System effect

I’m trying to create a marching ants effect, like in photoshop, to show a region that has been copied.

I’m using niagara for this, and the particle is fine but it takes time for the “ants” to march over from their spawn point to their end point, which obviously looks bad. Instead, what I want is for them to instantly spawn in, fully populated, basically skipping ahead in the simulation timeline.

Attempts:

I’ve tried speeding up the system time really fast, then setting the time dilation back to 1. Issue here is that there appears to be a relatively slow max speed.

I also found various functions relating to setting desired age, seeking to desired age, setting update mode to desired age, etc., none of which provide any feedback of any kind as if they’re all empty functions.

// This should enable seeking
Line->SetAgeUpdateMode(ENiagaraAgeUpdateMode::DesiredAge);

// Should prevent the sim from resetting whenever seeking
Line->SetCanRenderWhileSeeking(true);

// Should Allow much larger jumps while seeking
Line->SetSeekDelta(10);

// Should jump to this age, right?
Line->SetDesiredAge(4);

// I'm not sure how these differ from each other, but this doesn't work either
Line->SeekToDesiredAge(4);

I’ve also tried these in different orders, but there’s nothing, no feedback that shows that this is changing anything. I’m also doing this in BeginPlay if that’s relavent. I’ve tried these functions in different orders to, literally nothing changes.

All I want is to skip ahead in the timeline of the effect, like you can do in the editor. I feel like this shouldn’t be hard, but there’s no documentation on it. Any thoughts?

1 Like

Bump, because I have been having the exact same issue over the last couple of months. Cant get the seeking to work.

I use Blueprints, but you should be able to do this with ‘Advance Simulation by Time’:

Sounds like this may also be easier to accomplish with a material tbh, depending on your use case.