How to burn a house down. Without burning the house down.

[Anson Fogel]

Oh Oracle that is the RedUser Community:

I'm shooting another short film, and this one requires an old cabin to burn at the end, after being shot not burning here and there. However, the cabin can't actually burn - not the primary location anyway. It need not do the full burn to the ground - really, we need one wide shot with the structure on fire, and some detail shots of elements with fire spreading. The elements burning can be built and burnt fairly easily, its the wider shot(s) thats a trick.

Of course, there is no budget. Its a short. And its a very easy short to shoot, with this one killer exception.

I'm about 1/3 redneck and can work out the various details and tricks with fire, construction, etc itself with some other folks. But I'm a relative post- SFX rookie. Some thoughts:

1. Can I build another smaller version, shoot it burning on green screen then composite it with the wide shot of the real, non burning location, adding smoke in the real location, for example? Fire and green screen is challenging I hear. But that was my first instinct.

2. Is it relatively easy to do well completely in a computer these days? Fire is a tough one...not free, but not 5 figures?

3. Cobble and composite various stock fire / objects / houses burning footage?

Thank you oh Oracle, I know you have the answers.

 

[David Mullen ASC]

You could do what they did for "Return of the King" when that funeral pyre was burning around the actors... they built an identical bonfire at a right angle to the first one, lit that, and reflected it over the non-burning funeral pyre using a sheet of glass in front of the camera lens. Now I don't expect you to build the barn in full-scale but perhaps you could build a basic shape, painted black, in 1/4 scale and reflect that over the real barn (or composite it later in post.) Or just create it all in post using CGI.

 

[Anson Fogel]

Thank You

Thank You

David,

Thank you deeply for your willingness to reply to folks like me quickly and thoughtfully. That is a wonderful idea. I could plausibly shoot the "proxy" burn both through glass reflecting, as well as separately for options in post. The trick would be exposure - its an early evening light setting, not night as is the norm for such scenes, which makes the glass reflection trick, well, tricky. I can't really just light the fire to be X stops over the background real object! I might do some tests. Also, doing the proxy burn on that location means shutting a county road down, not easy to do, but plausible.

I would love to hear feedback WRT the options for entirely CG and for compositing as well....

 

[Ken Waller]

http://tinyurl.com/32kj8q8 Anson, This site has some free tips and free fire elements to do a burning house in FCP or AE using live FX compositing. If the shot is locked down it should be really simple. They have a HD FX page and a SD one. Good luck.

 

[Michael Romano]

When you do the plate shot, make sure to account for the lighting. Have sources coming from inside the structure illuminating the trees and surrounding area with a warm color. Another great location is from behind the structure, out in all directions. That will allow you to hide the source but fire it all up. Not sure of your budget but Shadowmakers (Flicker gags) are excellent for smaller lights. Alternate would be hand controlled dimmers. You need to have the flicker to pull it off. If you have access to large tungsten lights I'd go for 2K's with variacs, controlled by hand to emulate flicker. I'd use straw gels on the heads.

Good luck!

 

[Elsie N]

One other option is to just rewrite the scene. For instance, show a butane stove hissing, then show a hot water heater pilot light, then show a big explosion and a hole where the cabin used to be.:emote_head_explode:

 

[Vladimir Cassel]

I've used FumeFX some to good results. Here's a sample off of YouTube - http://www.youtube.com/watch?v=A3Jvzab6Tso

You'll need 3dsMax, a good computer (render times are harrowing), and some compositing skills though...

 

[Charles Angus]

American Cinematographer recently had an article where they faced much the same thing.

I do believe they burnt the place down, though (purposefully, not accidentally...).

Fire in miniature does not really look very convincing to me. If absolute realism is your goal, that would be out. Smoke and fire are hard to key, too.

My recommendation would be to build a smaller (say 3/4) mock-up of the real cabin, and shoot that burning. The trick would be to either find a similar enough location that it would sell as the same place (might be not too hard, depending - shooting a time of day we haven't seen before and a different angle would help), or setting it up close enough to the real cabin that you can position the camera so as to see only the mockup.

That and selling the size.

Once it's well and truly ablaze, any differences in construction will likely not be obvious.

My two cents.

Oh, and the fire department will want to know about any unusual burning. You could get in a lot of trouble.

 

[Joe G.]

"One other option is to just rewrite the scene. "

Which is where we get to ask all the relevant questions. Why is this house burning? Are any characters interacting with the house during the burning? Can the thing be cut, or just moved to exposition without any loss?

Assuming the answer to the last one is no, then what exactly is the purpose of this fire in the story? There could be dozens of ways of implying it without burning down the neighborhood.

Do people die in their beds?

Can you just show the fire catching, starting to spread in one room. In the bedroom, people sleep, and smoke pours in. Cut to Coroner and body bags... etc?

 

[Brent J. Craig]

As Charles said, make sure you get the fire department involved! Even small fire gags can go wrong very quickly. Don't be the film crew that burns down a forest (or worse).

Maybe there is a volunteer fire department in the area that would be happy to use your set for training.

Safety first, regardless of your budget.

 

[Dan Hudgins]

Hanging Miniature

Hanging Miniature

My recommendation would be to build a smaller (say 3/4) mock-up of the real cabin, and shoot that burning. ...setting it up close enough to the real cabin that you can position the camera so as to see only the mockup.

I like this idea best, using a Hanging Miniature (on stilts that can be roto out later using the same shot without the Hanging Miniature in place as the plate),

1) The time of day and angle of the light will match, the ratio of flame to daylight will be realistic, although you might want to shoot early or late to have the flames show up as at Noon you might not see much other than smoke.

2) Its possable to align the Hanging Miniature to block the actual building 1:1 so that the perspective is real looking.

3) Although 3/4 scale would be good, you might get by with a smaller scale, and have some of the smoke and flames coming from from a 2nd Hanging Miniature of less detail and more combustible BEHIND the smaller detailed Hanging Miniature.

4) You can pump in extra smoke and flames into the front miniature to suplement its natural burning.

5) You can wait until night and reshoot the miniature burning to get better flame footage and super those flames over the daylight take with the smoke in it.

6) You can make several miniatures with regestration pins in the bottom to mate to a fixture for making several shots, something you would not do with the real building.

7) The front miniature does not need to be all 6 sides, since the camera will only see maybe 3 sides, so it is lighter weight and lower cost to build than the full object, depending on how much inside shows as it burns. Depending on what shows and where the flames and smoke come out, you might get by with a 2D photo of the building glued to plywood or metal plate with small holes drilled (or slits) for smoke to come out of, or a 2D model in place of a 3D model.

 

[Anson Fogel]

Thanks everyone, great input - a few more answers and questions:

SCRIPT CHANGES/MOTIVES: No, the script cannot be changed to eliminate the wide shot of the house burning - trust me, that was my first instinct. If it could be done, I would not be asking the Oracle here. It can't. Really. Its the last shot in the short, and its gotta be that way.

SHOT: The shot really HAS to be the house, wide, burning within its setting in the landscape, early evening. Trust me. Prior to that, we use cutaways and tighter shots of elements of the fire spreading/starting, and that is not the challenge - I can do those shots. Its the wide shot of the house on fire that is the entire trick.

MINIATURES: Dan, the concept is great - killer idea. But, as other posters point out, fire does not look right at much smaller scales. Mr. Mullen's suggestion of a 1/4 scale or even full scale facade is doable, however - that and / or CG, combinations of, seem likely to produce the best results.

FIRE SAFETY: I will be enlisting the rural county fire dept for this area, for participation, safety, approvals, etc - I know some of them, and the local county film commission is also cooperative.

So I lean towards this:

Shoot the actual house/scene as follows (simple wide shot, only front and part of one side of structure in frame view + surrounding land):
1. The right tunsgsten sources and flicker both from within the house (window and door effect) and from behind and shooting from hidden areas onto surrounding grounds, trees, etc
2. Produce lots of smoke in and behind the actual house (its abandoned and derelict, so can get the right to do this part) coming out windows and from behind the structure.
3. Perhaps use air cannons to shot some debris up here and there form behind for dynamics of things catching

Shoot a second FX plate on black BG of a 1/2-3/4 scale model of the visible portions same position and size in frame (using Dan's approach basically) from no burn to well on fire. Shoot with same light angles, position, etc of course. Shooting this on-site using the glass plate method is not easy due to the layout of the site, so just shoot it on black and composite in post.

In Post, hire someone skilled with 3ds and such to composite it, using some/all/none of the FX plate, and add CG FX layers to the final image composite using FumeFX.

In post, we have the raw materials to have options - we have the right smoke and surrounding light from the actual location. We have the model burning for compositing fodder, and we use FumeFX for filler and/or for all of it if the model plate does not work out or look right.

What do you all think?
For heavy smoke, suggestions? We've done tires in barrels to good effect before, put those behind the real structure - do any rental smoke machine produce heavy enough smoke for the smoke coming out the windows?
Know any talented 3ds / CG geek kids who wanna give it a shot for a non-ILM rate?

 

[Mark L. Pederson]

This is one of those threads that just shows how cool Reduser is.

 

[Russ McDonald]

Save yourself time and money, building models and air canons. Action essentials 2k shot with a Red. Videocopilot.net has all the elements you need. A lot cheaper and a lot more controlable

 

[Craig Ryan]

You could do what they did for "Return of the King" when that funeral pyre was burning around the actors... they built an identical bonfire at a right angle to the first one, lit that, and reflected it over the non-burning funeral pyre using a sheet of glass in front of the camera lens. Now I don't expect you to build the barn in full-scale but perhaps you could build a basic shape, painted black, in 1/4 scale and reflect that over the real barn (or composite it later in post.) Or just create it all in post using CGI.

Wow, I was going to suggest the exact same thing as I read the OP. I just watched all 3 Extended Edition Appendices this week.

While the subject of miniatures is at hand, a while back I recall finding a formula used to calculate the appropriate frame rate for a given scale for miniature work. Does anyone know the formula?

 

[Anson Fogel]

Mark you are so right

Mark you are so right

Mark,

I passionately agree! I refer to RedUser as the Oracle only partially in jest. Where else can a relative rookie in rural nowhere Colorado ask a fairly complex esoteric question, and have it addressed by a well respected ASC Cinematographer, well, in minutes, then have a literal wealth of knowledge and experience thrown brought to bear further on the question within hours from around the globe? All from experienced folks, but not just that - with RESPECT and a genuine interest in helping. Wow.

Thank you all.

Now, back to the question - how about my proposed strategy and new related questions?

 

[Vladimir Cassel]

In Post, hire someone skilled with 3ds and such to composite it, using some/all/none of the FX plate, and add CG FX layers to the final image composite using FumeFX.

In post, we have the raw materials to have options - we have the right smoke and surrounding light from the actual location. We have the model burning for compositing fodder, and we use FumeFX for filler and/or for all of it if the model plate does not work out or look right.

What do you all think?
For heavy smoke, suggestions? We've done tires in barrels to good effect before, put those behind the real structure - do any rental smoke machine produce heavy enough smoke for the smoke coming out the windows?
Know any talented 3ds / CG geek kids who wanna give it a shot for a non-ILM rate?

FumeFX is great because you can render out seperate layers for the fire and smoke.

I'd offer to give it a shot for you, but I have no production work under my belt. It's a pretty simple procedure as I would just work the settings until it matches found footage of a real cabin fire, but I don't know if I'd do it justice on the compositing side.

 

[Anson Fogel]

The all CG approach composited onto the right wide scene with the right lighting effects, smoke, etc sure seems like the deal - I'm amazed at how good the FumeFX stuff looks - its not at all "CG-ey" - does anyone have examples of burning structures done via compositing and Fume or the like?

The Action Essential library is promising as well thanks, but there does not appear to be a way to see what actual FX are on the DVD's other than a typed list...

 

[Vladimir Cassel]

The all CG approach composited onto the right wide scene with the right lighting effects, smoke, etc sure seems like the deal - I'm amazed at how good the FumeFX stuff looks - its not at all "CG-ey" - does anyone have examples of burning structures done via compositing and Fume or the like?

The Action Essential library is promising as well thanks, but there does not appear to be a way to see what actual FX are on the DVD's other than a typed list...

Yeah, FumeFX is the real deal and the go to app for fluid dynamics in motion pictures. Would be even cooler if you can recreate parts of the cabin in 3D because Fume can interact with objects.

Another cool option is sprites in Particle Flow in Max. Basically particles that always face the camera with live footage of fire composited onto them. The Balrog in LOTR was done this way, I believe.

If you don't end up finding a pro to do this for you, let me know. I'll give it a shot.

 

[M Most]

Wow, I was going to suggest the exact same thing as I read the OP. I just watched all 3 Extended Edition Appendices this week.

While the subject of miniatures is at hand, a while back I recall finding a formula used to calculate the appropriate frame rate for a given scale for miniature work. Does anyone know the formula?

24 times the square root of the relative scale (size of the original/size of the miniature). For example, a 1/10 scale miniature would usually be shot at about 3.2*24fps, or about 76fps, to achieve "normal" motion.