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I have a question
#1
I'm doing a test with a sphere. What I have done was I created a ground plane and a sphere that is positioned above the ground plane. I used reactor to have the ball bounce on the ground plane and then roll of the plane. I have FumeFX applied to the sphere and I'm currently simulating. Its a 200 frame animation. I have the quality set at 5 and the maximum iterations at 500. At its current settings the simulation will take about 6 hrs to do

Now if I set the quality setting to like 2 and the max iterations at 200, obviously the sim will be somewhat faster. So I changed my settings to that and then simulated it.

Is there anyway of speeding up the simulations without sacrificing the quality look of the fire?
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#2
For majority of simulations, you'll need maximum of 120-160 iterations for maximum realisim that solver can provide. With more itereations, you will notice no difference at all - simulations will be exactly the same.
You might wonder why is that ?

Solver is working iteratively to reach an exact solution of fluid flow equations. For most of simulations, exact solution will be reached in 120 iterations, and if you have some extreme velocities in the grid - solver would need more than 200.

Quality 5 will produce very accurate solutions, and if you need to make a preview animation, you can use Quality 3 or 4 as you already did.

Excpet by tweaking solver quality, here are some ways to speed up simulation.

1. Increase Grid Spacing
2. Do not use Cubic Interpolation
3. Set Advection Stride to 0.5 (there is no need to go below 0.1)
4. For rough sim previews, you can set Adaptive Sensitivity to 0.1. Be careful with this parameter as adaptive grid might not stretch fast enough.

Regards,

Kresimir
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#3
sitnisati Wrote:For majority of simulations, you'll need maximum of 120-160 iterations for maximum realisim that solver can provide. With more itereations, you will notice no difference at all - simulations will be exactly the same.
You might wonder why is that ?

Solver is working iteratively to reach an exact solution of fluid flow equations. For most of simulations, exact solution will be reached in 120 iterations, and if you have some extreme velocities in the grid - solver would need more than 200.

Quality 5 will produce very accurate solutions, and if you need to make a preview animation, you can use Quality 3 or 4 as you already did.

Excpet by tweaking solver quality, here are some ways to speed up simulation.

1. Increase Grid Spacing
2. Do not use Cubic Interpolation
3. Set Advection Stride to 0.5 (there is no need to go below 0.1)
4. For rough sim previews, you can set Adaptive Sensitivity to 0.1. Be careful with this parameter as adaptive grid might not stretch fast enough.

Regards,

Kresimir

Cool thanks for the tip. My render times have decreased and thats cool.

Now my next question:

I want to do something like this:

[Image: hellboyreferencepicey2.th.jpg]

Although the following tests aren't that bad, to me, the fire isn't tendril enough like the one in the reference pic. I've played around with some settings but I'm still missing something:

[Image: hellboyfire2iw8.th.jpg]
[Image: hellboyfire1my4.th.jpg]
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#4
Lol.. Everyone wants to get Crazy effects at first..

Suggestion :

- Use the Texture map Intensity with some animated phase on the source of the fire
- Get a nice Environement Turbulance setup so that Any fire u create in the grid evoluates properly and as disired
- Get some Grid Spacing Low to accomodate the Size of ur "whites" on the texture map on the source
- Tweek ur Boiency and vorticity and expension and burn rate and ignition temperature should pretty low..
- Use another Map for the Temperature comming from the source , High temperature on a Solid Setup will allow u to reach leaking flame and Natural Behaviors
- Start with Set in the source on ur parameters , all though any reference of real fire effect to reach is an Additive mixture , ull get and reach stable and high scale solutions with set parameters

Cheers,
<!-- w --><a class="postlink" href="http://www.cgfluids.com">http://www.cgfluids.com</a><!-- w -->
  Reply
#5
Dukeofhasard Wrote:Lol.. Everyone wants to get Crazy effects at first..

Suggestion :

- Use the Texture map Intensity with some animated phase on the source of the fire
- Get a nice Environement Turbulance setup so that Any fire u create in the grid evoluates properly and as disired
- Get some Grid Spacing Low to accomodate the Size of ur "whites" on the texture map on the source
- Tweek ur Boiency and vorticity and expension and burn rate and ignition temperature should pretty low..
- Use another Map for the Temperature comming from the source , High temperature on a Solid Setup will allow u to reach leaking flame and Natural Behaviors
- Start with Set in the source on ur parameters , all though any reference of real fire effect to reach is an Additive mixture , ull get and reach stable and high scale solutions with set parameters

Cheers,

Thanks for the tips man.

Now onto my next question:

What I have done was modeled a hand and matched moved it onto a live action shot of myself. I've setup FumeFX to emit the fire from the hand. When I run the simulation, I get the following error:

Warning: Couldn't allocate field 12
Warning: Couldn't allocate field 13

Then it ends the simulation. What am I doing wrong here?
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#6
You need to increase grid spacing as you've ran out of memory.
If your grid is more than 300x300x300 voxels big, you might see that message (depending on RAM installed in your computer and also differs between 32 and 64 bit OS).

Kresimir
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#7
sitnisati Wrote:You need to increase grid spacing as you've ran out of memory.
If your grid is more than 300x300x300 voxels big, you might see that message (depending on RAM installed in your computer and also differs between 32 and 64 bit OS).

Kresimir

Thanks man. Thats what it was. My grid size was too big because of how big the model was but I resized everything and all is good. Big Grin
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#8
Here's a test clip of the blue fire effect only this time its applied to a hand I modeled and matched move onto the live action plate. Its 2 sec long.

http://www.visual-chaos.com/hand_fire_test.mov

But looking at it, it doesn't seem right. I know my whites are to bright but if I tone them down, the effect has a neon look to it and looks kinda dumb. I've played around with the settings but I still can't get the look I want.

Yes I've read the PDF file thats included with the plugin but I'm still having difficulty understanding the settings and stuff so any help would greatly be appreciated.

Oh and when will training DVDs be released for this plugin? I'm just dying to get my hands on them so I can learn more about the ins and outs of this plugin.
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#9
Fire movement along your hand looks good !
You can open preview window and tweak fire shader settings until you get results you want.
Did you download all video tutorials ? I think they can help you to understand FumeFX a bit more.
After the holidays, we will prepare more learnings videos for our members area.

Regards,

Kresimir
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