I need to burn an old wooden shack (20 X 30, one story) in the forest. However, I have neither the resources nor the budget to build a real shack and burn it for real (the land owner won't risk his trees). How realistic is the CGI solution? If we build the shack ourselves and make it look like charred remains, how easy will it be to add flames in post?

I've seen some pretty bad CGI fires, but I guess I wouldn't recognize the really good ones as fake (which is what would make them good ;-) ). Are there links to videos on the web showing this effect done convincingly?

Don't use CGI flames if you want a believable look. Detonation Films (http://www.detonationfilms.com/) might have something readily available for you to order or maybe Artbeats - Royalty Free HD Stock Footage for the Creative Professional (http://www.artbeats.com/)
Overlaying real footage has surprisingly good results.

Don't use CGI flames if you want a believable look. Detonation Films (http://www.detonationfilms.com/) might have something readily available for you to order or maybe Artbeats - Royalty Free HD Stock Footage for the Creative Professional (http://www.artbeats.com/)
Overlaying real footage has surprisingly good results.

I looked at some videos on the net, and I agree, CGI is the worst solution. Some quick & dirty vids using overlays showed real promises, I think that hiring a talented FX guy and shooting the structure made to look burned out would yield the best results.

J.

Use a tripod shots and you will have a lot of options later.

Use a tripod shots and you will have a lot of options later.

by that I assume you mean that if the camera is locked down, it is easier to composite in footage than if the cam is bouncing all over.

to burn in the forest, and no one was there to see it....


What if you just had a smoldering shack, and let the audience fill in the idea of the flames? Maybe reveal a shack that just burned down? this could allow for the use of small -controllable flames if actual flames were needed...

Just thinking from a cheap mindset.

Mike W.

to burn in the forest, and no one was there to see it....

"...would it still need to be budgeted?" ;-)

What if you just had a smoldering shack, and let the audience fill in the idea of the flames? Maybe reveal a shack that just burned down? this could allow for the use of small -controllable flames if actual flames were needed...

I can't have any flames at all (it might be set on a maple grove, and the land owner won't want to risk the tree$), but I do need to show the structure being consumed by the fires of hell (literally).


J.

This is kind of involved, but you could build a 1/3 or 1/4 scale miniature of the shack and burn THAT... easier to control than burning the real one, and you could probably get away with not showing very much of the surroundings.

Regarding real fire, my suggestion is not to light so much as a match without full permits, insurance, trained crew, fire brigade and any and all other requirements outlined in the the law.

A fire getting out of hand is a serious criminal offense, possibly leading to manslaughter charges if someone dies as a result of the fire. The implications of thousands of acres of destroyed forest and property are also serious.

Regarding real fire, my suggestion is not to light so much as a match without full permits, insurance, trained crew, fire brigade and any and all other requirements outlined in the the law.

A fire getting out of hand is a serious criminal offense, possibly leading to manslaughter charges if someone dies as a result of the fire. The implications of thousands of acres of destroyed forest and property are also serious.

Precisely why I'm trying to do it as an FX.


J.

I'm with Emma on this one, if you build a model (the bigger the better the flames will scale) and place it well away from his trees and use a bit of forced perspective filming from in amongst the trees (like 50 yards back or something) it should be pretty effective. A model like that is simple and cheap to build and personally id shoot at the telephoto end of the lense for the depth of field.

Only thing stopping you here is your diy skills

Andy.

PS. I know Jack is the word of reason here and is just looking out for your safety and to any other people reading with the same idea as you but the truth is you have to be hollywood to afford the list of requirements he made.........thats why we call it guerilla filmmaking.......crazy not stupid (i'll play the little devil on your other shoulder)

I'm with Emma on this one, if you build a model (the bigger the better the flames will scale) and place it well away from his trees and use a bit of forced perspective filming from in amongst the trees (like 50 yards back or something) it should be pretty effective. A model like that is simple and cheap to build and personally id shoot at the telephoto end of the lense for the depth of field.

Thanks, the model is a viable alternative.


J.

What about tossing a smoke bomb in the shack? Might make overlaying stock fire footage easier.

Personally, I would burn a model against greenscreen and comp it into a wide forest shot for the wide, and get closeups and pans across the model as it burned. I would also make sure to overcrank everything, I've found that fire in miniature looks more realistic in slow mo for some reason.

The downside to this is that fire and smoke is hell to get a clean chromakey pull from. I don't know what you're shooting on but I wouldn't try this with HDV or lower.

That's assuming you can't get away with the forced perspective trick that Andy mentioned.

My vote is with the model, green screen approach. If you do it outdoors in full sun I'll bet you won't even need to light it.

I've only used black screens for that type of keying (Smoke and fire) and it's pretty easy, especially since you can use a blending mode in 1 second instead of taking the time to key it. I've always assumed a green screen wouldn't work as well.
I'd use a black model resembling the shack to set on fire, and superimpose that video on the real shack. That could be done pretty quickly too, so it would be worth trying even if you do end up building a miniature replica.

Just on the cg side of things. Maya has built in fire samples. They are ok, but if its a daylight scene the fire wouldnt look so good.
The best cg fire at the moment that isnt proprietary software is probably fume fx.


FumeFX fireball on Vimeo (http://www.vimeo.com/1276541)

fumefx flame test on Vimeo (http://www.vimeo.com/2546383)

FumeFX burning wood log - HD on Vimeo (http://www.vimeo.com/1354006)


I think the black screen compositing method is used a lot in professional fx. You can also get stock clips of fire and smoke form online sites for this purpose.

I'll put in a second for FumeFX, but it's not easy and you need 3ds max for it. Check out the 'sample A' from this training DVD:

ALLAN MCKAY - FUME FX ADVANCED DVD (http://www.allanmckay.com/FFXDVD2.html)