Thick Smoke Dissipation

Work in progress

And this is what I mix up: A huge loResGrid for the smoke with a small hiResGrid for the fire - with very different setting, but I think the result will fit my needs…

Sascha

you can try to decrease the upper SPF limit for faster sim. and you can experiment with some randomization too

MORNING

Early Bird, eh? What time is it in Bulgaria?

Yeah, I slightly bring up randomization, but I think I have to use it carefully, because it diffuses the smoke quite much and releases it from the ceiling. I have to test very much, so I´ll try your SPF-hint to speed up simulation. What do you think would be a good value for the upper SPF limit?

If I reduce it from 10 to 5 it doesn´t seem to have any impact…

Work in progress

The same with lower resolution (8mio). Behaves slightly different…

…but simulates muuuch faster - about 6-7 hours for that - the 16mio grid would simulate over 2 days… - …I would think that the upper SPF limit would more affect a higher grid resolution, ist that right?

Early Bird, eh? What time is it in Bulgaria? first in the office! :slight_smile: actually it was about 9:30 am not a big deal :slight_smile:

to the work: the upper SPF limit is important if you SPF value reaches it. otherwise it is not used, and the result will be the same.

Yeah, thought that, the sim gives me always something between 1 and 2 SPF. What would happen if I increase or decrease the lower limit? If I increase it to 2 - does no sim take place at all? And what happens when decreasing?

try to increase the advection step parameter and to decrease the lower spf limit

Ivaylo.

Some weeks ago I finished the job and now I want to share the result: http://www.chaosgroup.com/forums/vbulletin/showthread.php?70552-secudo

Thank you again for your support! It was amazing!

And…

…another job ahead: Maybe I have to make a Molotov-Cocktail! So I have another question:

Will it be possible to achieve (nearly) this with Phoenix?

http://youtu.be/lfvceHUBWnU?hd=1

A fracturing bottle with MassFX, filled with Phoenix liquid, flying through the air, smashing, firing up and exploding?

What do you think? Will I make this?

I think I will have much much more questions in the time coming… :wink:

Sascha

yes, i saw the videos in the image section. :slight_smile:
about the molotov, i think it is possible. first simulate the liquid. attach the simulator to the bottle and simulate the break, by default the “wind from movement” option is on, so the moving simulator will cause exactly the same effect as a moving bottle in astatic simulator. the second part is the fire itself, just select the first simulator as source in the second, the liquid surface will start to emit fire automatically

Ivaylo!

Do you like it? And do you like the “BODO”-animation? http://www.chaosgroup.com/forums/vbulletin/showthread.php?70553-Bodo :slight_smile:

Sounds good :slight_smile:

Yeah, sounds like a good approach. So I think it would be possible to activate the adaptive grid - as long as the liquid is kept inside the bottle the grid should keep it´s shape - and after crashing the bottle the grid is growing as big as needed to let the liquid splash through the scene, am I right? Or is it better to work with two grids? One moving and one static - to switch between in the moment of crash? And let the liquid from the moving simulator drive the liquid for the static simulator?

And here I have a direct question: from where is the fire emitted? Equally all over the liquid surface? Or can I ignite the fire at a special point - as if I hold a burning match at a certain point - and the fire grows form there?

Realistically I have a burning fabric that ignites the liquid in the moment the bottle crashes and the liquid touches the fabric. So I will have at least three sims: the liquid, the burning fabric and the fire from the liquid ignited by the fabric. Do you think I shall try to build this scenario like in real and let Phoenix calculate all? Or do I have to cheat anything?

And while thinking about: maybe I have an idea to overcome the problem that Phoenix does not react on deforming surfaces… - …testing… - …or are any updates planned on this issue? :wink:

Thank you and kind regards.

Sascha

By the way…

…if I want to let the fabric burn I have to solve the deforming-meshes issue…

Deforming meshes test

Not too bad!


Teapot = simple rigid body
Yellow boxes = PFlow particles
Red fabric = deforming mesh

sometimes the lack of correct reacting is not so visible :slight_smile:

Ivaylo!

Thanks for answering.

I think it would be possible to activate the adaptive grid - as long as the liquid is kept inside the bottle the grid should keep it´s shape - and after crashing the bottle the grid is growing as big as needed to let the liquid splash through the scene, am I right? Or is it better to work with two grids? One moving and one static - to switch between in the moment of crash? And let the liquid from the moving simulator drive the liquid for the static simulator?

Thank you for your help.

Sascha

yes, the adaptive grid should do the trick. the other idea, to switch between two grids, looks weird for me.
just move the grid, break the bottle, and let the simulation to do the rest.

Thanks Ivaylo. I hope the job comes, that would be a really cool animation…

Seems to me that smoke simply needs a dissipation parameter. If we’re talking about real-world behavior, steam dissipates a lot faster than a burning rubber tire.

Bob

Yep, the job is there - so a molotov-cocktail is up to come :wink:

yes, definitively smoke dissipation is needed, and we will add it. currently you can workaround it using temperature based opacity+cooling.
this is how i made this simple test

Hi Ivaylo,

can you tell me is smoke dissipation implemented? if not then when can we expect to see it?

thx