vortex cloud

[Jean Bennamias]

Hi all,

I would like to ask if anyone have any ideas to do a similar thing with phoenix (maya)

I have to do a vortex, spinning for few moment (faster in the center, slower when it's farther), and at the end, it's closing quite fast, then the clouds have to be static.

anyone ?

thanks

https://vimeo.com/121203270?from=outro-local

[Jean Bennamias]

I started with some geo to have the shape I wanted.
I emit from this shape with a first source, no velocity, just smoke, and a bit of temperature.

On side, I did a simulation of particle to create and control the motion.
I have created an other source, only for the velocity from my particles.

So in my simulator set, I have the two sources, the emit and the one to advect my smoke from my particles.
I have also added a drag field to try to keep the smoke in bloc.

Do you think I am on the right way ?

Any suggestions ?

I would like to post some screenshot, but unfortunately I can't upload anything, sorry...

Thanks

[Ivaylo Katev]

i will redirect your question to our support team, because i'm not familiar with maya, but just making a parallel with max , there must be a vortex force that can is used exactly for such simulations.

[Jean Bennamias]

Hi Ivaylo,

Thanks a lot.

There is a vortex field, but it's tricky to drive your sim exactely how you want only with your fluid container + some fields. That's why I doing my motion sim with particles, easier and faster to control the motion.

The tricky part is to adjust the advection from the particles to the fluid.

[Ivaylo Katev]

i think if you put the particles in a source, that has no active channels except velocity, this should work.
using drag field is not a good idea at all, because the drag kills the smoke turbulence

[Jean Bennamias]

My source with particles has only velocity active, in injected mode. It works, I just have to play with the value of velocity and discharge.

If I don't use a drag field in my simulator node, the smoke get crazy and I am loosing the cloud shape effect.

Any suggestion to replace the drag field way, and keeping the cloud shape ?

[Ivaylo Katev]

better replace inject with brush, inject mode will not create pure air mixing it with the smoke, perhaps this is the reason why the smoke gets crazy

[Jean Bennamias]

yep, just after my post I was trying brush mode

from the help doc : Brush - the objects update the fluid parameters, slowly bringing them to the specified values. When this mode is selected the Discharge parameter specifies the speed at which the transition takes place.

About the discharge, the value means when it's high, it's gonna be faster for the transition or the opposite ?

Still doing my test with brush, yep, I have a better effect...

[Ivaylo Katev]

the discharge in brush mode has valid values from 0 to 100, the bigger value produces faster effect, but suppresses the fluid natural movement, replacing the velocity with the source object's one. so, i suggest 10-20 is good, if you have time to wait the vortex to reach the final speed.