Repair ribbon hole
The intention of those mini tutorials is to have simply searchable reference for the implementation of fundamental concepts in Niagara.
In the present day I wish to have a fast have a look at how we would resolve a typical subject when utilizing Ribbons.
Until you spawn a particle each single body, there’ll at all times be a spot between the supply of the ribbon and the ribbon itself.
Spawning a particle each body, is usually a answer in some circumstances, however it’s typically higher to discover a answer in which you’ll be able to bridge that hole
There are just a few methods to take care of this, however I’d wish to current a reasonably fundamental one that may work in a lot of conditions.
Fundamental Setup
The technique right here will likely be to reliably discover the final spawned particle and snap it to our supply location (the emitter place on this instance).
We do that by, for each particle, evaluating the index of that particle with the entire variety of particles which have been spawned within the emitter. Within the case that we do have the final spawned particle, we set the Place of the particle to the simulation place.
Now to know the entire variety of particles we nonetheless have to hold monitor of that by some means.
To do that, we’ll regulate the SpawnPerUnit and SpawnRate modules. (You’ll most likely wish to create a replica for this.)
On the finish of the modules we will add a bit part that reads the spawn rely and provides it to Emitter.TotalParticlesSpawned.
And increase now the final particle of your ribbon will stay hooked up to the supply.
Besides that’s not solely the case.
As a consequence of tick order it’s doable that this script will likely be executed earlier than the motion script of the supply.
This will create a one body hole between the final particle and the supply.
We will resolve this on a case by case foundation, by forcing the Niagara Tick to later within the body.
That is usually ailing suggested as a result of it takes away the engines skill to utilize threading in an environment friendly manner, but when used sparingly it may be useful.
And there you go, a fairly strong method to make your ribbons gap-less.
Get pleasure from.
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After GPU Ribbon is on the market to Niagara I’m now not too bothered with this subject, however I nonetheless wish to share a much less correct however barely simpler answer to the hole subject when utilizing Spawn Charge.
This method assumes the consumer to stay with a relentless spawn price worth, as a result of there’s little or no level of randomizing the spawn price worth each body in a ribbon emitter. Anyway as a result of the spawn price worth is fixed, we will merely calculate the spawn interval in second by 1/SpawnRateValue, then in Particle Replace stage, do a Lerp Place and select between SimulationPosition and Particles.Preliminary.Place (or simply Particles.Place relies on your use case) by checking if the Particles.Age is smaller than the spawn interval.
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@ifurkend Humorous sufficient, somebody asking learn how to do your described technique for spawn per unit, is what triggered me to search for the introduced technique.
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If we’re speaking about the identical man, he truly wished the latest particle to transcend the actor place, which is feasible with our strategies, however it saddens me that it now not issues now (not due to the GPU ribbon).
That is truly the identical technique as Partikel’s tip proper, simply not executed in scratchpad 
and thanks for the nice tip as nicely Niels!
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I’ve a query, as a result of I’m unable to learn what’s earlier than this (or extra like they’re too superior!), what does SpawnOutputInfo return? To my understanding, it appears you’re taking out the each rely of particle spawn and accumulate them to the Emitter.TotalParticlesSpawned.
It might be nice in the event you might clarify extra about this half, thanks.
it appears you’re taking out the each rely of particle spawn and accumulate them to the Emitter.TotalParticlesSpawned.
Yup, that’s precisely what we’re doing.
Spawn data is the construction a spawn module passes onto the engine to point that it desires to spawn new particles.
For those who open up one of many epic offered spawn modules, you’ll discover that the final node in these modules is the one I marked in white.
So we merely copy the epic present modules and put these nodes within the image behind it to verify what number of particles this modules desires to spawn and add it to our rely.
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Hey Niels!
I attempted your tutorial however for the second half (fixing the spawn price or spawn per unit) when compiling the module script it tells me there’s errors :
I’m unsure what to do since two of them are positioned on nodes that got here from the fundamental spawn price module. The final one is the map set on the finish (the one you add) however I suppose this error is brought on by the 2 others errors.
Are you able to assist me please ?
