Vortex
 

Hey gang,

I need to make a spiraling vortex of clouds and asteroids for my camera to fly through so I thought, what better than to use a Vortex field. Only the thing is I can't come up with any settings that are any good. Everything I try, the vortex starts off spiraling nicely, but the radius quickly expands exponentially and gets huge. The docs claim you can keep that from happening by setting the conserve value to 0, but what that does is bunch all of the particles up into a ver very tight spiral like a pole and then spins them in that form.

Does anyone know of any good tutorials or can you offer me any advice here.

Thanks,
-dann

hmm... it would depend on what exactly you wanted, but you could try creating the overall effect, saving their initial state, and then perhaps applying the vortex with conserve at 0? I would think they'd stay in their conserve shape and just spin.

that's actually about what I did, but they don't stay in their shape, they contract into a very tight spiral

Weird?
In the docs it says:
Tip:
If you use a vortex field with a particle object, you can set the Conserve attribute of the particle object to influence of the motion. If you set Conserve to 0, the particle object moves in a circular motion. If you set Conserve greater than 0, you get a spiraling motion.

I believe I tried to create a glaxy type of effect some time ago, and I had that same problem too.
My problem, If I can remember, was that I had my Vortex magnitude set too high, along with other random incorrect settings....

I'll try this later today when I have more time, and I'll post my settings to make it work:)

Cool?

PS: But I think Mike it right, in that all you "should" have to do is:
- emit some particles
- set initial state for selected when you are happy with the amount of particles
- rewind
- set particle conserve value to .95, or lower, depending on how you want it.
- Apply the Vortex field to the selected particle shape.
- Play with the Magniude to get the spin you want.
- Add other fields to taste.

Again, I'll try it tonight, and post my results, ans settings for this, as this has always made me mad as well:)

OK guys. It sounds like you don't believe me when I tell you I did exactly what the docs say to do, exactly what you are telling me to do, but got very different results. So... here is the playblast and my Maya test file to show you what happens.

Thanks,
-dann

watch the playblast

It is NOT like we do not believe you:) hehe...

On the contrary,
These forums are viewed by everyone, so stating the basics first is a standard operating procedure, and neither Mike nor I meant to imply or accuse you of anything.

Anyhoo.....

I took a look at your playblast, and I noticed something that you did not mention in your first post about your problem.

It looks to me, like you are using some sort of volume in there?
Whether it be a volume field, and/or volume emitter?

This WILL make a difference if I am to try to re-create your problem later, so I will download your file to see what that is:)

Thanks!

I know, I was trying to make a little joke. I guess it didn't translate. Sorry.

Anyhow, yeah I used a volume emitter so that my particles wouldn't have any inertia except what was supplied by the vortex. It doesn't really matter though. I get the same result with an Omni emitter.

Yup. You're right, it doesn't matter, but I just wanted to be sure is all:)

Ok, I took a look, and I was able to get your particles spining fine without collapsing upon themselves, and/or expanding outward to noticably at all.

Just increase your Vortex fileds' Attenuation to 4 or greater, and you will be fine within your frame range.

That is the only change I made, other than the basic cleanup of your Emitters' Distance/Direction attribute was left at 100.

(Though that had no bearing on the final outcome, when you are troubleshooting dynamics, it is always a good thing to start one node at a time:) hehe...

Good luck! and lets see a render when you are done! :)

Here is your file with those 2 changes made:

PS, please remember that the nature of the Vortex field is to
PULL an object in a circular or spiraling direction.

So, by that nature, depending on other fields, shapes or object settings, most often your particles WILL get PULLED in upon themselves first, before other objects, fields, etc. take over.

The trick to pulling off this illusion, is to find that "happy" medium of Vortex attenuation, to emitter conserve ratio that gives your galaxies that beautifull spin..... on life:)