Hello,
So I’m having an issue with changing a particle system on the fly.
The use I have for it is a strong wind that periodically strenghen itself before being calmer, pushing the mist away, then coming back normally.
I modify the Acceleration module so that the mist particles are pushed off in a direction to indicate the strong wind.
I’ve followed guides on how to change a particle system on the fly and it works more or less correctly. (Changing acceleration with particle system vector nodes, changing the parametters to DRm direct in the particle system)
However, there’s one thing I can’t get to wrap my head around.
When I change the Acceleration module in play, the particles already spawned don’t gain the acceleration. So I’ve got particles that have the correct speed while already spawned particles just float around with 0 acceleration.
How do I get EVERY particles, spawned before or after, to go into a direction selected in blueprints ?
I made a terrible picture to better explain what my problem is :
EDIT: Here’s an example showing how you can do it:
This has to be done during the updating of the particles, since that’s their tick update. The key is to create a user variable that you can then reference from blueprints(the name of the variable is case sensitive AFAIK). I used the linear force, might be others you can use. But as you can see, the particles are all moving with the changes in applied force. I just used a timeline for the example, obviously use whatever method you need and make sure to add some kind of multiplier to tweak the strength of it. MAKE SURE YOU HAVE A DRAG IN THERE otherwise, the particles might not want to swing around the way you want them too
Oh and these are GPU particles, so it works fine with them from what I can see. I thought this might be some CPU vs GPU particle issue at first, but I guess not.
Sorry for the poor quality video, I don’t have time to upload something better:
I haven’t messed around with FX in a while, so there might be better ways to do this all. Hopefully this gets you on the right track.
Thanks a lot for your answer and help!
I haven’t tested niagara particles yet and am not too familiar with it, however it seems to be a little more flexible than the classic particle system, I don’t know why I didn’t think of it before.
Do you know if what you made here is possible in the classic particle system ?
Oh wow, I didn’t know you were trying this with cascade. As far as I know, they have pretty much completely depricated and moved on from cascade. There should be a plugin for converting cascade systems to niagara systems, but you’ll have to look around to double check. You might need some guides to help understand the changes going from the one to the other.
I do not know if you can pull stuff like this off with cascade systems and it’s been way too long for me to remember for sure. Niagara is probably the best realtime particle simulation system out there. It’s insane what you can do with it and how much control you can have over effects with it, but it does have a bit of a learning curve for more advanced things. I’d highly recommend you make the transition, if you are wanting to create more advanced effects like this.
Oh well I spent a few days trying to make it work when I was just playing with dinosaur bones it seems! I thought it was just a parallel system with different positives and negatives. It shouldn’t be too hard to transpose my mist system to Niagara. To be honest it’s a relief because I was loosing my mind trying to make this work. Thanks for your answers!
