[VFX] Cascade - Ribbons and Events....

Hey all, I’m working on a particle system that uses several emitters and event generators to drive them. One of the event-generated emitters is the source for one of the ribbon emitters. That event generated emitter is kicked off about every 6 seconds and emits in a random location based on the generator particle’s position at the time of death.

On the first firing of that event (burst), all the ribbons look great and are where they should be (trailing behind every particle). However, on each subsequent emission, there is a rogue ribbon who’s tail end begins at the emission position of the* previous* burst and draws all the way to the new position of the current burst. It will continue like this forever until I restart the sim.

Any ideas?

Oh, and one other thing, my ribbons don’t trail very smoothly behind the source particle…they kind of “jump” every few frames…

Thanks!

JP

have you tried delay the ribbon emitter ever so slightly? might stop that attaching to old source issue. I’d have to test it, but that’s what I’d try. As for the jumping, does it look like it skips the sprite that frame? could be particle count, could be the loop resetting… um. I’d try forcing the emitter to loop super consistently instead of just emitting at a rate. That might work, but w/o testing I can’t say for sure. Can you post images of the jumping?

Hey thanks for the reply.

I tried several delays on your suggestion but I still get the error. I’m newish to Cascade but not to particle systems…did I run into an old issue?:stuck_out_tongue:

The “skipping” really shows up toward the end of the source particle’s life, when the velocity slows way down. I’ll try to grab a picture or video, but basically the start of the ribbon lags behind the source particle in “steps”, popping back into place as if to catch up. I can probably just affect size over life so that as the source particle slows, the ribbon fades away…but that’d be a workaround if there’s not a solution.

Here’s a video (it’s a giant AVI, sorry) that shows some of the ribbon hitching…please ignore my stand-in electric rice…

https://app.box.com/shared/static/48p3yi4gtgj2wbtlav9i.avi

One other thought I had was the “Kill on Complete” check box on the required. DL’ing the vid…

Yeah, I had tried that too…no dice. I even checked that for every particle in the event chain…rogue ribbon still attaches at previous spawn location…

hmm well looking at your video, that problem always exists b/c its just stitching together sprites. I’d guess its the rate. Are you using “spawn per unit”?

Yeah, I was curious if it was just down to the velocity…and how long I’m keeping them alive\visible. Yep, spawn per unit and spawn module turned off…

That issue I can finesse my way around easy enough…but that rogue ribbon is driving me crazy…

However, I suppose I could get around it by using a blue-print to fire off the effect multiple times without it looping…

Still though, I’d like to know why it’s happening and how to fix it…so I can avoid it in the future

Try bursting them instead of spawn rating them or remove spawn per unit. Burst 1 for a start to see how it behaves.

Well, I solved the hitching issue…in Ribbon Data, I just had to up the Max Particle in Trail Count. Smoothed it out quite a bit…

Edit: to clarify, the ribbon as a whole is smoother, but at slow velocity, you can still see the “catching up”

That’s actually how I tried them at first…but, correct me if I’m wrong, if the source particle is moving, then the ribbon particles have to be spawn per unit? Default spawing or bursts on the ribbon data doesn’t produce any ribbons at all without spawn per unit for me, unless I’m doing something wrong of course…

Yes, Think you can’t have them together. Thats why i said remove the spawn per unit but i forgot the ribbon needs constant spawning, If you see the catching up try using local space or lowering the detection distance on the spawn per unit so that it spawns more?

Cool thanks for the suggestions! Local space had no effect, but upping the distribution rate in the spawn per unit module smoothed out the catching up pretty much completely. Awesome.

Now, if I could just figure out the rogue ribbon business.

Hey cccprobot -

I have watched your video and am trying to make sure that I am seeing the correct rogue ribbon.

939506f1f8bdc179f4135509cb40cd2c55d73e1e.jpeg

Am I looking at the correct element? And have you made sure that it is in fact a ribbon and not the spawning event that we are seeing there.

Let me know, I am curious -

Eric, thanks for the reply! That video was to show the sort of “catching up” of the ribbons. Let me record a video that shows the rogue ribbon and post again. Sorry I hadn’t already.

Ok, here’s a screenshot and a video. Screenshot you can see that a single ribbon starts from the last burst (event) origin but it’s attached to a new burst particle…so the ribbon is drawing all the way up to the new spawn and then continues with the new particle source.

https://app.box.com/shared/static/sojt4enju1gso06ov18q.mov

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Hey cccprobot -

I think I might know what the problem with the rogue ribbon. Is the explosion portion of your effect reused each time? Because I am pretty sure that the ribbon is still visible and the origin point moves then the new explosion happens which is creating your rogue ribbon. I’m going to run a test to see if I can give you a clear way to correct this issue. Let me know if I am barking up the wrong tree.

That’s exactly what I had first thought of as well. I’ve had this happen in other VFX tools. However, when I ticked the boxes in my various emitters to kill on complete, or set my durations low, it doesn’t seem to have an affect. It certainly “feels” like that’s the case, but I don’t know how to stop it or if I can. :slight_smile:

Also I’m more than happy to send you the asset file if you want to specifically see how I have it set up.

That would be great. You can PM me a link if you want to keep it private.

PM sent! Thanks!