Dynamite fire (fluid) settings question

rinktoaster · 07-27-2007, 12:32 AM

Wondering if anyone using the Dynamite plug-in in fluid sim mode for a fire effect has found a good method to make flames dissisipate (become transparent) as they rise for a certain period or for a certain distance, like real fire. As with most fire sims, you can adjust this "life" property when using particles, but when using the fluid mode (which creates the best overall fire effect I think), the flames flow vertically forever for the full height of the sim box. The diffusion/dissolve setting seems to have no effect. I've thought about using the "Use LW texture" mode and selecting a gradient with distance from ground as the input, but the normal choices for input channel are not available.
Thanks for any help.

Phil · 07-27-2007, 06:55 AM

The LW texture input puts hard edges on the volume. Your best option is the diffusion setting, I think, unless I am misunderstanding you. Diffusion has a strong effect here, at least for me. You do need to recalculate the simulation, though.

It has to be said that I'm somewhat frustrated that Can hasn't updated this plugin since release. I had hoped for a lot more.

rinktoaster · 07-27-2007, 08:21 AM

Phil,
Thanks for the info. Could you describe how you've gotten good results with the diffusion value? I'm experimenting with the settings on the "moving ball" fire scene that can be downloaded from Can's site. I've tried diffusion values from negative, zero, & positive, up to extreme values of +/-100,000 and see no difference in flame life/height.. the tendrils still boil up vertically to the top of the simulation box in all cases (always recalculating each time I change values of course). Wondering if other settings or modes need to be a certain way for diffusion to have any affect?

Phil · 07-27-2007, 05:23 PM

I had a dose of config file corruption. I'm back on my feet and will endeavour to hook up something over the weekend for you. Nudge me by PM if I forget.

eyelandarts · 10-08-2007, 02:59 PM

Bringing back this thread from days past. Have you guys had any problems using dynamite fluid mode and 9.3? Im having problems calculating a simple smoke stack for more than 200 frames when it goes all crazy.
Any help apreciated. Is there a place to go for dynamite Q's?

Phil · 10-08-2007, 03:34 PM

No problems here with scenes up to 600 frames long. What kind of issues are you having?

Dynamite 1.2 is in beta at the moment...

eyelandarts · 10-08-2007, 03:40 PM

Thanks for answering im using Dynamite 1.13b. How do I get 1.2? The problem im having is the fluid calculates as expected then suddenly the fluid just resets and tries to pick up from some other point in space. I dont remember the demo doing it so maybe I can calculate it in there and then use the cache from that one.

Intuition · 10-08-2007, 05:46 PM

Quote:

Originally Posted by Phil

No problems here with scenes up to 600 frames long. What kind of issues are you having?

Dynamite 1.2 is in beta at the moment...

Dynamite 1.2???? Gimme Gimme Gimme!!!!

RedBull · 10-08-2007, 07:42 PM

Quote:

Originally Posted by Intuition

Dynamite 1.2???? Gimme Gimme Gimme!!!!

Email Can, and he is usually pretty good at that kind of thing, especially if you are having an issue with the current release build.

Phil · 10-09-2007, 02:44 AM

Quote:

Originally Posted by eyelandarts

Thanks for answering im using Dynamite 1.13b. How do I get 1.2? The problem im having is the fluid calculates as expected then suddenly the fluid just resets and tries to pick up from some other point in space. I dont remember the demo doing it so maybe I can calculate it in there and then use the cache from that one.

I'd be interested in seeing that - there are a few immediate possibilities to explain that, but it could also be a bug. Any chance you could email me sample content that shows this (without the cache file - that would be painfully large)?

phil{dot}stopford~at~googlemail[dot]com

eyelandarts · 10-09-2007, 09:02 AM

Thanks for your help Phil...Sent!

Phil · 10-09-2007, 09:21 AM

Cool. Give me a couple of hours to get back to you

Phil · 10-09-2007, 11:46 AM

Hmmm. No mail arrived here yet.

eyelandarts · 10-09-2007, 11:52 AM

strange, let me try again.

oops, yeah I ate the L in mail.

Phil · 10-09-2007, 12:35 PM

Hmm. You are generating a huge amount of data with those settings. I changed the following :

cell size : 120 mm
X 30
Y 83
Z 30

Running the simulation generates a cache file of 2.3 GB and the simulation runs in a relatively short time. I'm wondering if you are simply generating too large a cache file.

I'm still poking around, but that's my gut feeling. Those changes don't show an issue and I haven't yet seen a crazy smokestack