I'm not sure how to do it, but I can tell you that if you use CGI fire it will look fake if you don't do something to light the walls of the burning room. Fire casts light after all. Bright flames in an otherwise dark room can look weird and is a give-away to CGI fire.

RJSchwarz
San Diego, CA

I can't quite remember, but if you check out the LOTR extended edition special features, they showed how they made it look like the character was burning in the pyre in Return of the King (it did involve real fire, but a camera trick to make it look like the fire was surrounding the character). It might help, anyway.

'In the life that man creates for himself, he too, creates his demise... and his legacy.'

In the movie BEASTMASTER they had an establishing shot of the city, which of course was a model, but they wanted it to look real so they put torches next to the front gate. To do this they put little mirrors where there torches should be and angled everything so that real fire was reflected in the little mirrors.

A trick you might be able to employ if you end up burning down a model house or something since burning models never look good. Mirrors in the windows could reflect a distant fireplace making it look like the fire was inside.

Okay, I think I should get bonus points for an answer that references BEASTMASTER, I mean how often does that movie come up in film conversations in a useful way. ;?)

RJSchwarz
San Diego, CA

You're getting into dangerous territory using real flames, but if you must have at least a small local flame,maybe the start of the conflagration, don't just buy some petrol, meths, whatever.

A comedy magician I made props for used a thixotropic glue for fire effects on stage. It smears on, so only goes where you put it and doesn't spread. It also burns for a limited time until the solvent vapours are gone and then stops. It will still make a mess of any clothing.

I can't suggest you do this, but take note of the dangers of using a liquid fuel that can spill, run, creap without you realising until you touch a match to it and it's too late.

In several films I've seen, they use footlights to light the character- who writhes and screams in agony- while shooting through flames in the foreground. It can be a very effective story-telling device.

Yadayadayada

If you're shooting in a live room, it might be a little harder, but still possible...it would be better if you used a simple 3-side room (2 walls and a floor) set, but shine orange lights at the scene for the lighting effect and then simply use CGI...as for the animation part, just keep asking around, I've met at least 3 people online that have done some CGI (flying bullets, 007 gunbarrel, etc.) for me. Good luck!

"'It doesn't bother you, killing those people?' 'Well I wouldn't be very good at my job if it did.'"
-Casino Royale

In that scene in LOTR, instead of using a mirror they used an angled pane of glass, so you could see through it to the pyre, but would still reflect the adjacent fire.

Prepare to Fecht!