Houdini Smoke - rocket thruster effect..any tips?

[Akabane]

Hi there, i'm trying to achieve the effect of a rocket launching.

I accomplished the trail with particles, and i made them collide (and die) with the terrain.

Then i used the died particles to emit smoke with a Smoke Solver.

The problem is, first, how to control the expansion of the smoke? The Gas Diffuse microsolver doesnt seem to work. And the Gas Dissipate does exactly what the name says, and that's not what i need.

Second, how to achieve that "rolling smoke" effect, like the smoke that's building on intself?

any help is appreciated

Akabane

[mightcouldb1]

I believe what you are talking about is turbulence or noise. You can use the force DOP, or make your own force VOP. As far as the rolling smoke, vorticles should give you that effect. Try playing around with the force scale and radius.

Edited May 10, 2010 by mightcouldb1

[Akabane]

Thanks!

Another couple of questions:

-I advected vorticles inside the smoke, and tweaked magnitue and radius...that's particularly cool because you can use your own particles to drive the fluid's motion.

They also give a good turbulence effect; but i cannot obtain the "rolling effect" whatsoever.

The only thing i obtain is some style of "wispy" smoke with vorticles...

I also adjusted the Vortex Confinement to break up the shape a little more.

Anyhow, nothing i can do (to my knowledge) to obtain the rolling smoke effect.

-How to say to the smoke emitted from the particles to keep the velocity the particle has? (sort of an "initial velocity")

I saw in the smoke solver that there is "Net New Source" to velocity, so i think that it inserts a NEW velocity in the smoke. So i'm stuck. The other options are "None" and "Weighted Average"...but the average of what? The source velocity and...0?

-EDIT: And how to set the amount of density emitted from the particles? ç_ç

Thanks for any further help,

respect

Akabane

Edited May 11, 2010 by Akabane

[anupamd]

Thanks!

Another couple of questions:

-I advected vorticles inside the smoke, and tweaked magnitue and radius...that's particularly cool because you can use your own particles to drive the fluid's motion.

They also give a good turbulence effect; but i cannot obtain the "rolling effect" whatsoever.

The only thing i obtain is some style of "wispy" smoke with vorticles...

I also adjusted the Vortex Confinement to break up the shape a little more.

Anyhow, nothing i can do (to my knowledge) to obtain the rolling smoke effect.

-How to say to the smoke emitted from the particles to keep the velocity the particle has? (sort of an "initial velocity")

I saw in the smoke solver that there is "Net New Source" to velocity, so i think that it inserts a NEW velocity in the smoke. So i'm stuck. The other options are "None" and "Weighted Average"...but the average of what? The source velocity and...0?

-EDIT: And how to set the amount of density emitted from the particles? ç_ç

Thanks for any further help,

respect

Akabane

[anupamd]

so basically your trying to create a billowing smoke effect such as this.. but against a wall?

http://www.sidefx.com/

(rocket launch houdini 10 demo)

- try playing with the fluid temperature and a high cooling rate. The hotter the fluid, it will tend to rise and billow.

- once you get the temperature right you can play with the vorticles.

- add some noise to the emitter and random initial velocity to get some puffs.

- try just a stand alone billowing smoke effect first, and then apply the same setup to your specific case. Simplify the problem?

Edited May 17, 2010 by anupamd