Smoke Ring

[Chadwick]

Hey everyone,

I am quite the newb when it comes to FX in general but I am trying to re-create a smoke ring like one blown from a cigarette smoker.

I have thought of a few way to go about it, but I was wondering what solutions you guys might offer. Because this is an assignment, I have to use particles.

I have though about advecting the particles to get more fluid movement and then also resitricting particle movement within a torus to get the actual ring.

Thanks.

[lukeiamyourfather]

Because this is an assignment, I have to use particles.

Wow, that sucks. Volumes would be a much more suitable approach in my opinion. I'd definitely go the route of advecting particles through a simulated volume if particles are the only option. Like real smoke rings you need a smoke source and then after emitting some smoke push air through the middle of it which forms the ring. Check out the pyro videos on the SESI site if you're new to the volume simulations. Not using volume simulations for advection is an option but I think realistic results (for a smoke ring) would be difficult to obtain using only particles.

[michael]

try scattering particles within a torus, then have it turn inside out...if you know what I maen...

[GallenWolf]

I checked out some youtube vids on smoke rings (very interesting) - for the ring itself, I'd probably try an all-sops, non particle approach and render 'em as sprites. If the ring itself needs to be particles as well, I'd say perhaps consider using follow pop to get particles to chase the smoke ring, but I have doubts that will give the "look".

Or, do a static simulation of the particles held inside a torus, then instance that sim on a single point moving away :3

Alvin

[Chadwick]

So here is what I ended up doing:

I built a torus translating and scaling it with expressions and using a mountain node with an expression to add noise.

I reversed the normals and had the Torus emit particles by volume, with the particles bouncing off the interior of the torus.

The trail of smoke was added by having the existing particles birth more particles with noise and a slight upward force.

Shaded with standard dust puff sprite and had them alpha out with a color node.

It turned out alright. some things still need to be fixed. I am having a hard time containing the particles within the torus and oversampling the collisions seam to make things worse.

Any suggestions?