How do I gain control of the smoke behavior ?

[vanja_kapetanovic]

Hey guys, I got some particles going with the PFlow and I am adding smoke from Phoenix to create a tornado. My problem is smoke is totally out of control and it doesn't follow particles. It disperse all over the place. I tried less or more particles, less or more smoke, less or more quality and resolution and even steps. Do you guys have an idea how to fix this? Basically I would like to limit smoke as much as I can to a particle area as seen in the video. I haven't shown much of my sim here but I did it like 100 times and I can't get it right. Thank you
https://www.youtube.com/watch?v=hpU2...ature=youtu.be

It should hopefully look like in this tutorial once done. He is using Fume Fx but principles are the same
https://www.youtube.com/watch?v=w5kczThz00g

P.S. This is EDIT
I bumped resolution significantly and changed grid from Adaptive to regular and I think it might be workiing. Will post shots soon.

[vanja_kapetanovic]

This screenshot perfectly shows why this is so hard to do. You can clearly see that phoenix fd smoke is like 5 times wider and covers more grid than actual particles and takes up like extra few mil voxels just spreding uncontrollably.. even at this high resolution and quality it's much larger and more unpredictabe. This is what I meant by there is absolutely nothing to help predict this behavior. At least It not clear to me. I will try to turn off all the smoke and all smoke related settings and introduce it 0.001 and go from there to see if amount would change the behavior.

[georgi.zhekov]

Hey,

Check out this tutorial here - https://docs.chaosgroup.com/display/PHX4MAX/Dust+Devil
It skips the pflow part and uses only the Vortex force directly affecting the smoke.

As for your scene, make sure to put the forces you're using for the particles in the Exclude list in the Scene Interaction rollout of the simulator. This way they will affect only the pFlow particles and won't affect the smoke.

Hope this helps.

Cheers!

[vanja_kapetanovic]

Hey,

Check out this tutorial here - https://docs.chaosgroup.com/display/PHX4MAX/Dust+Devil
It skips the pflow part and uses only the Vortex force directly affecting the smoke.

As for your scene, make sure to put the forces you're using for the particles in the Exclude list in the Scene Interaction rollout of the simulator. This way they will affect only the pFlow particles and won't affect the smoke.

Hope this helps.

Cheers!

Wow thank you for that insight. I always thought that if I exclude forces then they won't have any effect on my sim. Also is it possible to have 2 or more grids for 2 or more layers of tornado. Lets say Middle part, than wide ring around it and such. Of course with their dedicated Sources and PFlows. I am trying it out now. This is what I am getting with 2 grids and 2PFlows and 2 different sources. I t's working but struggling to process it all in time. I am not sure if this is a valid technique so let me know if this is something that would make sense for multi layered sims or how would be the most optimal and efficient way to go about it. Thank you.

[georgi.zhekov]

In your case you're using forces for the pFlow particles, but if you used them for Phoenix as well, the effect will be double. That's why you need to exclude them. If you don't use pFlow, then you won't have to exclude the forces.

As for the layering, sure you can add as many grids as you want. Though you will need to exclude the forces again, the sources from the first grid and may be the first grid itself if you don't want them to interact with the original simulation.