smoke along a path

[chris_img]

Hi there, i'm working on a setup where a stream of smoke flows around an object, like a wind tunnel. I've looked at the wind tunnel example but cannot use such confined setup (limiting the smoke to a thin bouondary). I'm trying to get the smoke to follow a spline instead using the path follow force but i'm stuggling to get to do a few things:

1. a small sphere at the start of the path is the emitter, but it always creates an expanding mushroom cloud before the path influences it away.

2.the follow path pull speed spinner seems to have very little influence. I'm currently on 8000 & i still want the stream to hug the path tighter.

3.at the beginning the smoke should be a fine nozzle like diameter then spread out a bit as it flows around the object, is there any way to control that?

cheers,
chris/

[Svetlin.Nikolov]

Hey,

1. Fluids create mushrooms, this is what makes them look like a fluid. If you want to have less of this effect, reduce the Fluidity (Conservation) quality under the Dynamics rollout to a single-digit number. Also you could try to key the discharge of the source so that it creates less smoke at first and then increase the amount of smoke (or the strength of the emission, or both).

2. It is weird that the pull speed does not have a sufficient effect. What if you force it to a really huge value? Could it be that the influence option is too low? Or could it be that the Pipe Radius is too high?

3. Not yet, we have it in the to-do list to allow changing of the radius of the path follow force along the length of the spline. Right now maybe you could cut the spline short, or use two splines after one another? Note that in case you have many path follow forces in the scene, you might have to decrease their influence option so that they don't go into a mutual tug of war.

Cheers!

[chris_img]

Hey thanks for replying, those answers are really helpfull thanks.

[chris_img]

I wonder if you could think of a way maybe i haven't thought of to replicate the smoke in this example:

https://youtu.be/Xv9O3-rvj58?t=39

I've resorted to using a spline with a mesh thickness piped into the gizmo list of a vray environment fog. but i'm finding out that i can't aniamte a noise texture down the spline to control the fog density.

[chris_img]

Well, i've found a suprising solution to this effect. Old school superspray with path spacewarp and a shit load of motion blur multipliers!

[Svetlin.Nikolov]

Yesss, this would allow you to control it much more precisely. In your reference I don't really see the streamlines curl or create vortices, so it seems you don't really need fluids for this kind of effect. E.g. the wind tunnel Phoenix example scene lets the fluid roll much more freely after its interaction with the geometry.

Cheers!