I've been experimenting on and off with cigarette smoke ideas. Here is a link to my best results so far:

Cigarette smoke

I used "smoke" sprites for this one. I hope to improve on this. I wish we still had both the materials and effects forums still going.

I'm wondering if a more natural looking cigarette smoke might work better with a tube shaped particle or streak emission, staying small diameter for a few inches then rapidly widening and slowing down as turbulence of some type would be applied. Check out some of the photos of cigarette smoke in the photos earlier in the thread posted above.

Any ideas about how to perhaps do this sort of "smoke tube"?

Here's what i think of as the characteristic smoke action

Click to view attachment


As it slows down it starts to look like it's folding on itself at the top.

Yep. Attached are a couple of cigarette smoke stream pictures that confirm your diagram quite well. I love the one that spirals! That's what I'm trying to simulate. I've got a reasonable approximation working using gravity, friction, and a cone shaped force setup (with turbulence), but I'm wondering how it might be improved. I've been using insense to get a better idea of how the smoke behaves.

Here's an idea I'm wondering about: How about creating an alpha mask so to speak, that approximates the smoke stream in its three regions (laminar, early turbulence, random turbulence). It could be a fixed mask, perhaps, but distorted dynamically with some sort of turbulence applied to the mask itself. Then, behind the mask you have "wall of sprites" that are only visible though the mask dense and bright and fast for the "laminar" region, decelerating and becoming more transparent for the early turbulent region, and slowing down and becoming almost transparent for the random region. The mask could give the warvy, swirly look, and the sprites the appearence of flow.

Or it might be simpler to do an animated image sequence, that could be switchable based on the movement of the cigarette. Use regular sprites or streaks when the cigarette is moving, and the image sequence when it is relatively stationary. Or streak/sprites for just the laminar part, and image sequences for the turbulence parts, animated with lag to account for the relative motion of the cigarette?

Check out the third picture of the guy smoking hundreds of cigarettes at the same time! One serious nicotine addict, I'd say!

one thing that will be hard to get is the well defined edges that the smoke has as it moves. It's not a soft haze/fog like we usually get with our semi-transparent sprites.

Perhaps modeled smoke is the best way to go for ultra-realistic edges and shapes? With Gradient Edge Transparency, SSS, Transparency, Translucency and Density settings, the "smoky" look should be achievable in patches. Granted, it is not automatic, although with dynamic constraints or lags, it would be possible to somewhat automate it. A zero-gravity SimCloth tube? Perhaps it could terminate in soft transparent sprites for the "cloudy" part?

I like the idea of using forceS (on a sprite emitter)... maybe one that pushes the smoke left, another pushing right...etc might warrant a test.

I gave up smoking about 10 years ago...but it was still FUN to do this: Hope it helps get you going! A cool part is the ashes... I used a gradient material from red to grey and added a roughness...

The SMOKE is 2 materials... both derived from the 2 smoke materials from the Hash CD...with about 4 hrs 'dinking'

This is one of the first ones I tried. This used streaks instead of sprites and a friction force with turbulence that rotated slowly above the cigarette. I didn't tweak it my so it does not look very natural, but it has nice curly streaks running through it similar to what real smoke would do. I should probably experiment with this possibility more. Perhaps a mix of sprites and a different type and settings for the turbulance.

I added another 'tendril' emitter... I don't know... I THINK it's looking pretty danged good! (But, I like bus fumes...)

that is very impressive.

That is most excellent Matt!

Coool! That is the best looking smoke effect that I have ever seen in A:M!
Quite painterly too.

Still imagery doesn't do this justice but here's a frame from the sequence:

Yah, Man! That's what I'm talking about! Fantastic!

I suppose similar techniques could be applied to the character as they blow smoke.

I think it is too straight at the beginning, but nevertheless: Very well done.

*Fuchur*

As a smoker myself I have to say none of these examples truly grasp it's spirit or... personality. (Yes, I have K.D. Lang's "Smoke" cd).

My thought is to use hair or cloth (possibly in combination with sprites?). It is the "particle" divisions at the beginning that don't look right to me. Cigarette smoke rarely comes out in "particles" with divisions. That is where the simulation breaks down in my opinion. I may try my own using a cloth simulation with force, or maybe several "hair" strands that start close and then really wiggle around to create the swirling tendrils as the smoke dissipates.

-vern

In the project I'm working on, total realism is not necessary, though since smoking is a major theme in the film I'd still like to do a decent job of it. My characters will definitely fit the make-believe category.

I got really close to something using cloth. The "cloth smoke" wiggles and rises just like a swirling spiral of smoke. Once it "stretches" to its limit it loses "steam". The problem is I can't seem to get a force object to influence the "smoke". I want to have a force at the top to "push down" on the "smoke" and cause some swirly action. I need to "hold" the cloth in place so it doesn't just float and stretch to infinity. After that i would play with material surface settings to create the "smokey" look to it.

The trick is to "fake" the continuous "flowing" of the cloth so it looks like it's streaming away but in reality it is just staying in one place. Some turbulence at the top. Smoke from a cigarette kind of has the same properties as cloth with no "gravity"... or a "reversed" gravity.

Do force objects effect cloth? Of course they do right?... hmm... Maybe my settings are off.

-vern

This will take a bit more experimenting I think. Maybe sprites could be the way to go after all. Maybe some longer more swirling sprites with variations in length. The problem with using cloth is the dang simulations and the forces needed to make it work. Sprites are more "flexible" and less constrictive.

-vern

No matter how hard I try... I just cannot picture you as a smoker Vern.
I have no idea why that is.

Keep thinking those positive thoughts! It may have an effect on me.


-vern

I think Vern smokes those 'left-handed' cigarettes...

I'm jiggy with what you are saying, Vernster... but there are ways to improve upon this yet. This test was a quick 1 pass render... if I used more passes and turned ON motion blur...OR I could up the particle emission numbers and conversely lower the opacity. I'd like to see your test.

THANKS for all the comments!

My tests never got much past;



By the time I was done I had a force object as big as the ground plane because the smoke kept "escaping" its influence and either flopping down on the ground or flying off to disappear into space.


I think you guys are on the right track with sprites. Motion blur and multipass would definately help I think. Definitely. Oh yeah baby... motion blur.

-vern

I'm a gonna set up a nice, looong weekend render...maybe let it continue smoking for 20 seconds...and tweek a little more and do the motion-blur idea on a higher multi-pass... so, till Monday- SMOKE 'EM IF YOU GOT 'EM!

OK- I'm done 'tooling around' with my cigarette. Here's the final-vinyl:

http://www.youtube.com/watch?v=t0GT3tDGvAE

WHAT I LEARNED: The particles reacted nicely to multiple forces, and with differing amounts of drag- reacted uniquely from one another. I bumped the amount of particles generated to over 2000 on the 'tendrils' which made this quite render intensive...so to avoid waiting for 35 min-per-frame numbers, I ended-up setting the render quality to SHADED, with only 2 passes- and the 'cheat of cheats'...I rendered the smoke separately from the BG and composited in After Effects (shame)

NEXT: I am going to change the smoke emitter from the 'DIM' on the Hash CD to a 'skull-N-crossbones' and see what happens!

Impressive Matt. Very impressive.

Hey, I don't mind compositing in After Effects. The end result is what I'm after, with the least amount of effort required to get the desired result. Any flexibility to tweak the end result after rendering is a good thing from my perspective, especially if it saves time and effort in the long run.

Matt, this is looking quite good for the application I have in mind.

cough cough great sample cough matt

Okay... couldn't leave it alone.

I came back to this with the cloth idea again. This time I used a cone shaped cloth "tube" with a smoke image decal. That I think will be temporary. I think I can create a "streamy-smokey" material then maybe even animate the material for more "smokiness".

I placed the tube with the big end facing up. The chor dynamics have a -5 on the y. There is a spherical force object this time (avoids the smoke escaping the force influence). This still needs some tweaking. I want to find a balance with the chor dynamics and the force so the downward dynamics and the force can maintain an "upward" motion. When the simulation starts the top end sort of "ripples" downwards and the force keeps pushing it back up.

It's not perfect yet but the potential for a Streamy-Smokiness-Effect® or SSE® can be achieved.

Click to view attachment

-vern

Here's another quick test with a turbulence combiner material:

Click to view attachment

I should try it with motion blur. I think with some fiddling of the material I could make this even better. One thing I want to do is decal a gradated transparency map along the edges to soften those hard edges of the splines. I also need to figure out a better way to make it "move". I keyed the Y translation of the perlin turbulence but it also makes it "flicker".

To make the cloth move I offset the spherical force down and increased the size and magnitude. There is only -2 on the Y dynamics of the chor. This keeps it moving slow. The upward force object still needs to be tweaked. The cloth tends to dip down too far. I am thinking two forces. One that is stronger at the base but drops off. Then another one at the top to make the clothy smoke swirl and dissipate.

Above the cloth smoke is a cylindrical material effector that fades the transparency. I also have a gradient material for the smoke so the end of the smoke goes transparent. That didn't work so well because the cloth tends to bend over on itself. I need a way to keep the smoke going "up" as much as possible. If I make the cloth stretch too much it looks good at first but then it becomes "heavy", it expands outside the force and falls down too far before going back up. It's a real balancing act. I may be over thinking this. But it's fun to experiment.

-vern

Vern,

I think these start to really capture that ribbon like quality of cigarette smoke. What about adding a particle emitter to the cloth? That would give you the ribbon and some cloudier random smoke.

I was thinking the same thing. The problem is that image sprites don't "bend"... I don't think they do do they? I have to test that. If smoke sprites could "bend" like if you could have a long single image that behaves like a "group" of particles... no... I don't think sprites can bend.

I suppose a sprite emitter could be added to "continue" the smoke effect. But to be VERY accurate, smoke like that doesn't start to get cloudy for quite a while. It dissipates but it still maintains a "stringy" quality for a while. The motion is based on the rippling effect. If you can get that proper rippling effect it looks like it's moving up. The other key is getting it to "disappear" or fade out at the "end".

I found this guys portfolio. Very helpful to study the quality of smoke... and yes... I borrowed one of the images for my earlier test.

http://sensitivelight.com/smoke2/

edit: actually this type of smoke is more like a fluid simulation than a particle simulation. It's very fluid.

-vern

The main problem I see with cloth is simulating the deceleration of the smoke stream. It goes from a narrow, fairly straight stream to a ribbon like bend and swirl, to chaotic turbulance, to diffused. Matt's setup is looking pretty good overall, even if it lacks the smooth ribbon like flows. For a cartoony character like mine, this should look pretty good.

The Sensitive Light link is a great reference! Thanks!

What about this:

a) Make a "cloth" cone, though like a small tube up to a point where it flares out. (I suppose that would be more of a funnel...but with a very thin nozzel.)

If it is possible to vary the stiffness of the cloth in a sort of gradient fashion, make the narrow tube part moderately stiff with only a slight drop in stiffness until the flare, where the stiffness would drop off rapidly. (Sorry, I don't know how to keep a "b" followed by a ")" from turning into a smiley with sunglasses.)

c) Use a gently breeze to slowly ripple the cloth, with more wind turbulence along the flared part.

d) Vary transparency vertically: nearly opaque along the narrow tube, and rapidly becoming transparent along the flare.

e) Then project an upward moving fine-grained texture to give the sense of upward flow--otherwise completely uniform, but modulated by the transparency.

The edges of the ripples should give you that look of transition from laminar flow to turbulence. For the completely diffused cloud part above, I suppose a volumetric effect would work best. I think the transparency fall-off and a slow rippling would probably avoid the issue of decelerating the upward flow.

Whaddya think?

Another idea:

Add one more technique to the ideas just posted: Animate the smoke effect separately at a higher frame rate (or the equivalent of a higher rate) and add it to the scene in "slow motion". The upward moving texture would have to be matched accordingly to look right in the slow-mo version. I'm just wondering if this might make the cloth dynamics easier to set up. Yes? No?

Another idea:

Is there a turbulence Materials effect that could displace the cone surface in random, fairly deep ripples? This would probably be easier to animate to change at a slow rate and the ripples would probably be easier to scale along the vertical. The cost, I'm assuming, would be longer rendering time.

Ha! That's what I did initially. I used a cone of cloth. I did not however think to use different types of cloth with the same model. The problem I had was the "weight". The top wide flared part of the cloth tended to flop over and fall down. I like those ideas of using different cloth types so the lower parts stay "smooth" and the upper part is more chaotic.

-vern

Perhaps somebody with more experience with lighting and surface properties, etc., could do this much better. The idea is to get the surface to be very transparent when viewed normal to the surface, whereas viewed along a tangent to the surface, the surface "accumulates" light creating almost a line. I don't know how to get the surface to render in this way. I want the surface to light up like the example from the Sensitive Light site.

Matt, would you share a project file to experiment with? That's looking plenty good for my cartoon style short film. I'd be glad to give you credit for developing the smoke effects.

Matt, looking at the project you posted earlier, I sort of get the gist of what you did. I like the idea of multiple forces.

I need to do this with a cigarette in the hand of an agitated, gesticulating character. The forces could be arranged around the character, who will be seated.

I suppose the same sort of arrangement might work for the character blowing smoke.

I gave this a shot using Robcat's streak emitter technique. It isn't exactly photo-realistic, but it didn't turn out too bad. This was rendered with just one pass, so it may be a little grainy. You can make the smoke as fine as you want by making the particles smaller and increasing the emission rate, but render times go up dramatically.

It's been 10 months since I last worked on this, but here's one thing I remember: Because of the high number of particles needed to get this effect, I ended up rendering a smoke pass in 'shaded' view on black, and comping the smoke back in- in AE. Glad to see this is still being looked at. Sure miss Vern!

Hey Matt I just watched your smoke vid on YouTube from like a year ago. Nice smoke! I guess I used *your* streak emitter technique. So much information is shared on these forums it is hard to keep track of it all.

Diggin your test Holmes... Can you make the particles live longer? Try doing the smoke element in shaded and comp it in post... it'll render a LOT faster and the quality is not bad since the sprite uses an image.

here's "my" streak method. The render times are lengthy but it avoids the noticeable repeating sprite image problem.

I've added the PRJ for the moving cigarette version to the first post.


However Matt's method has the advantage of being renderable in shaded mode for fast results.

Oh yeah, that's the one I remember. Great test!

Yeah- very convincing smoke...thanks for the PRJ...I'll have a look, how bad was the render times?

I'm wondering if an animated decal of cigarette smoke could be used as well. I'm thinking a set of decal animations, so when the character gestures with the hand holding the cigarette, the animated decal stays put and gradually fades, and a particle emitter kicks in while the cigarette is in motion.

You could also record cigarette smoke with minor gesturing and animate the hand and cigarette to match, sort of how we record dialogue first and animate to it later.

Sure, that would work, but you would have to get a good alpha channel as well.
You could shoot it against a green screen and knock it out in a compositing app ...
But since I don't have a green screen, I would try to shoot the cigarette smoke against a perfect black background. The lighting would have to illumine the smoke but not the backdrop.
Then make a copy of the video for a transparency map and punch up the contrast.

I might give this a try this weekend.

I wonder if I could do something like black light puppetry, dressed in black against a black background to film a sequence of just smoke.