Particle Emmiter and built/rez height - Randomness ?

This is going to sound crazy I know but I have to ask the question.

If you set a particle emitter off, and it's poofing out a few particles, and due to it's nature there's a built in randomness to the items being poofed out.

If you rez this prim (with the emitter script inside) at ground level, or at 4000m up in the air, there should be no difference at all with the speed/randomness of the poofs should there?

I make something that slowly poofs out a few shapes/textures and got it looking right at nearly 4000m up.

Yet, when I rez the same item at near ground level it appears to poof at a slower (less often rate)

I'd guess about 50% less poofs.

I know this is client side, so I can't imagine it's really happening. yet it seems to be.

Anyone else ever heard of this before?

Obviously you'd never notice it with 100's of things being poofed out every second, but I'm just using a very slow particle with not many so I'm noticing it.

am I mad?

My guess is that at ground level there are other particle sources in the viewers scope. The viewer is set to display a maximum number of particles. At 4,000m your device is the only source.

Try increasing your max particle count or look around for other sources. Fog, waterfalls, flowers - may not be obvious and may not register to your view but they are in the viewers range.

Rime

you have to remember that particles are also a shared pool resource.... if there are any other particle effects in the area they all draw from a common pool, once that pool of available particles is used up, they start fighting each other for resources (which lower the amount that each one can rez)

if you can, try to design your particle count to have the smallest number possible onscreen at one time.... (#/burst * (lifespan / frequency)) will give you the average.... less than 100 is decent, more than 200 begins to be obscene. doing this will cut down on possible side effects from other particle sources

Thanks.

Yes, I knew that was possibly going to be the initial and obvious reply.

But I don't think it's that.

I guess, we are assuming that it's only "particles in view) that we are talking about and not particles that are not being seen?

The weird thing is that, if anything, at 4000 (where I'm making this item) I had a lotof them running so have quite a lot of particles in view at the same time and they are running fine.

At ground level, rezzing the same item, looking out to see with no other particles in view (that I think of) they are poofing randomly (where the randomness comes from I don't know) a noticable amount less that at near 4000m where if anyhting there are loads more particles in view.

Ahhhhhh

An update..........

There must be more going on here, re particles and viewer and "What's IN VIEW" than we think.

I have just rezzed the same item as a sandbox and it's running fine.

The same as it runs at my build area (around the 4000m mark)

Yet, when I rez the item near ground level (as I said) it appears to produce particles at about HALF the "random" speed.

This is despite the fact I am looking "out at sea" with no particles in my view.

HOWEVER............

Im my house, I do have a shower/fountain, and bubble bath and some ghost lights and fire/smoke particles.

But they are either behind me (not in my field of vision) and/or also behind other prims.

So, if you imagine, the OTHER particle emmitors are behind two walls (prims) that are BEHIND me, and I'm looking AWAY from them at my slow running object I'm making.

So, it kinda MIGHT appear that perhaps (just perhaps) it's particles AROUND you despite the fact that they are no in your field of vision.

Do you think this might be possible?

I have no idea if this will work - but as a test try reducing your draw distance to the smallest possible. That should (might?) eliminate some other particle sources in the vicinity.

Another guess (I have no real knowledge of this) is that the viewer *is* aware of particle sources near you whether you look at them or not. Otherwise how would fireflies generated behind me appear over my head and drift away in front of me? Has to know they are coming, right?

Or not

Rime

Update Update............

To even more nail this one...........

I went back home and increased my particle count from the default 4096 and it fixed the issue.

As I said, I have a bathroom in my house with two lots of steam and bubbles and water jets (all particles) but they are two prim walls away and BEHIND ME.

So, As strange and implausable as it may sound, I winder if this 4096 limit (if you have your preferences set at the default) has nothing to do with your fields of view, but rather a radius (in all directions) from your Avatar's position.

Being only rezzed by the client, and that fact your client is not looking at it, I would never have thought this could be the case, and yet, it's kinda pointing towards this might be what's happening.

Perhaps someone with more knowlege on "how things work in the SL world) may be able to shed some clarity on this seemingly weird issue?

Particle emitters have to run whether the emitting prim is in view or not, because the cloud of particles that result can extend 60-100 meters from the center, so as long as the emitter is in draw distance at all it will run.

Otherwise you wouldn't see the smoke from the chimney behind you blowing past you, the clouds of many small particles wafting from that waterfall just over the ridge, the rain from the rainfall prim far above your head, and so on.

as argent said, it doesn't matter if they aren't in view or are hidden... they still count against the totals

This is similar to the way that textures rez in your potential field of view, even if you aren't looking at them at the moment. A popular way to "preload" textures for a slide show viewer, for example, is to display them on the hidden sides of the viewer (the back, the bottom, etc.) and then move them onto the front face after a decent time has passed. You can't see the textures until they actually appear on the face you are looking at, but the textures are rezzing nonetheless. If things didn't behave this way, you would have to wait for a new view to rez every time you looked in a new direction, even if you had been standing there for an hour.

Many Many thanks for your reply and advice.

Yet another thing (one up from Basic level!) I have learned and now I know (and you have explained) I guess it's pretty obvious.

Though I guess, although I KNEW the particles were going to be behind me. I honestly did not think they would "Count" towards my 4096 in view total, unless they were actually IN VIEW and being rendered by my client, as it's the client that 100% renders the things foolishly (he's says with a little SL sarcasm in his voice!) I assumed that as the client was not actually rendering them for me to see then it did not matter.

Obviously it's a total number of particles in your area (and it's not just down to draw distance as I've experimented a bit) that's the issue, and not just the ones you can actually see and be rendered.

Possibly it's draw distance PLUS the maximum dia and particle emmiters can emit to, which is the key distance issue.

I have a big problem with this issue and it's spoiling the items I'm building.

The reason it is, is that, unlike normal where you just say create LOADS of particles, I'm only creating a VERY few, and adjusting the speed to get "the look" right.

Due to this, I'm finding it hard to get the balance right, as I got them 100% spot on (for me) and when I rez them on the ground they run slow.

For my location, I think I MIGHT have nailed the problem down to a neighbour.

They own quite a large parcel next to me and all around the outside of their plot they have a water channel (their own make) and it's made from mostly rectangular prims, each prim having a animated transparent water texture and a smoke/emitter script.

There are 34 of these prim running all the time, and to be perfectly honest, unless you LOOK for it, you'd hardly see the dam particles (due to transparancy)

So, I have 34 "Particle System (smoke on the water)" emitters running next door, and I'm guessing these are the problem.

I did have a few emitters myself (fire, sea spray) but took 90% of mine away and only make a tiny difference to my speed problem.

Funnily enough, going back months and months and months, I have a jetski that I almost never use, but when I did it creates a giant particle spray behind it, and it never did produce such a big spray when near my location.

Ideally I'm like to have a nice word with the dutch lady who lives next door and ask any chance she might look at these 34 particle mist emmitors (that you can hardly see) and if she could do anything about it.

Or as it's rented land, I could ask the group that own the land if they could look into it, as it's affecting performance for others in the area.

I might be fold to go away and stop complaining! but I guess it's worth a try.

And she'll say yeah it's because the neighbour has all these particle effects that effect them, they look so different int the sky!

LOL

I was expecting something like that

I guess most of us think "our projects or items" are the ones that are important, and what's the other person doing

These 34 mist emittors next door are just one of those (been put down and forgot and can harldly be seen anyway) type of things, combined with the fact the area is deserted 99% of the time is kinda annoying when your area you spend a lot ot time in is being (im sure) affected.

I think I'm going to have to "Lump it" so to speak, but I'm generally allways one for the "Living together nicely" kinda ideal and would never let my tree branch overhang someones land, or put up a stupid wall that blocks someones view.

I've even looked ay my place from others views to see if I feel my build is affecting them in a bad way.

Still, it does not hurt to ask, she can only say no can't she.

Just as a small update.............

Not asked anything of anyone yet, and in a way it's done me a favour as I'd never have known there COULD be a problem if I rezzed my item elsewhere.

Have now created a control system which regulates the Burst Particle Count and this overcomes my problem now