video flames with alpha channel... help!?!!?

Jeff Waters wrote on 10/21/2006, 6:03 PM
Hi all,

I would like to layer some nice flames "licking" and "rolling" over the screen for a firefighter related video I am working on. Some of the flames would be used for a transition effect. Some would be used on title screens.

What options do I have for this? I'd like to use real flame footage (rather than CG stuff) if possible. But, I'd need it to have an alpha channel transparency so I can layer it "over" other things (text, video, etc) on the screen.

How can I achieve this? Is there stock footage with such transparency or perhaps some other application to help create it?

Thanks!
Jeff

Comments

Former user wrote on 10/21/2006, 6:35 PM
Particle Illusion has some very realistic flames (and render with an alpha channel)...

wondertouch.com

Jim
richard-courtney wrote on 10/21/2006, 7:01 PM
If you know someone with a wood burning fireplace you can get some
good flames. Darken the room and if you have ND filters add them to
hide seeing the back wall of the fireplace. Record at a low level at a safe
distance, remember there will be alot of infrared heat. Record just above the
top of the log without seeing the log. This should also hide any embers.

Place two copies of this video above your background. Make the second
copy a child and use MASK GENERATOR with the LUMINANCE type selected.
Set the compositing mode of parent to Multiply (Mask).
Adjust the LOW IN to start with.

Hope that will get you started..
TheHappyFriar wrote on 10/21/2006, 7:35 PM
let me see what I can get.. I've got a wood stove (close enough). But flames are real hard to do. I've tried it before with little success (a camera works great though).

If only I knew you wanted this... i burned a whole bunch of stuff yesterday night. :)

EDIT: i have particle illusion too, that would work great. I wouldn't use an alpha with real footage though, I'd probley do a chroma key. But that's something you'll have to expiriment with.
Spot|DSE wrote on 10/21/2006, 8:41 PM
All of the Artbeats flames libraries come with an alpha matte, making it clean and quick, but if you can get someone to shoot it clean for you, it's not terribly hard to matte it yourself.
TheHappyFriar wrote on 10/22/2006, 9:17 AM
i've got some flames I rendered out in particle illision. Want them? (they're screen wide DV files. ~1/6th screen hight flames, ~1/2 screen hight & ~1/4th with smoke)
Jim H wrote on 10/22/2006, 12:21 PM
Happy, If you're willing to share these files they would be a great part of anyone'e library. I for one, have overused the one low rez flames-with-alpha-channel clip that I have.
TheHappyFriar wrote on 10/22/2006, 5:20 PM
it might not be perfect but yeah, i'll let anyone use them.

It'll take me a few days to get them on my FTP (hopefully less though).
Mczet wrote on 10/23/2006, 1:22 PM
www.detonationfilms.com

There site is a bit of a disorganized mess but you can find free downloads of fire, smoke, expolsions, flashes and such.

TheHappyFriar wrote on 10/24/2006, 10:06 AM
http://www.sterlingshield.net/home/steve/video/flames_high.zip
http://www.sterlingshield.net/home/steve/video/flames_med.zip

i have another buy i'm having upload troubles. :(
TheHappyFriar wrote on 10/24/2006, 10:10 PM
the last one is up:

http://www.sterlingshield.net/home/steve/video/flames_low_smokey.zip
Jeff Waters wrote on 10/27/2006, 9:48 AM
Thanks everybody! Ok, I now have some flame footage and a corresponding matte of the flames. I'm a bit lost how to accomplish the effect, though.

Could someone treat me like a 2 year old and list out the specific steps? Thanks! In what order should the tracks for the flame footage, flame matte, and underlying video be? What are the compositing steps?


Ultimately here's what I'm looking for. I have some footage of a guy working out. I want to put flames over top of this footage. The flames should completely cover him up wherever I put it.

Thanks!
Jeff
TheHappyFriar wrote on 10/27/2006, 11:34 AM
Tracks in 1,2,3 order, 1 being topmost.

Guy on T3.
Flames on T2 & 1.
add a mask generator FX to track 1.
Make T2 a compositing child to T1 (the down arrow in on the T2 icon area).
on T1 change the compositing mode to Multiply (mask). that's directly to the right of the level slider.

All done! :)
richard-courtney wrote on 10/27/2006, 2:02 PM
You said it better than I did.
Jeff Waters wrote on 10/27/2006, 6:17 PM
Ok,
Pulling my hair out. I was able to get your method to work. Not sure I've wrapped my brain around it, though.

I purchased some Artbeats stock footage. It comes with fire footage and a corresponding fire matte. The matte has the fire as white and everything else as black. How do I use that?

Thanks!
Jeff
Jeff Waters wrote on 10/27/2006, 6:17 PM
Ok,
Pulling my hair out. I was able to get your method to work. Not sure I've wrapped my brain around it, though.

I purchased some Artbeats stock footage. It comes with fire footage and a corresponding fire matte. The matte has the fire as white and everything else as black. How do I use that?

Thanks!
Jeff
TheHappyFriar wrote on 10/27/2006, 6:25 PM
if you use the matte then put that on track 1 & don't bother using the mask plug in (i think). Do everything else though. I didn't bother with a matte because the mask generator & my particle-fire work good (if it was real fire a matte video would be a good idea).


re: rcourtney
I just spent the past two days editing words out of a pre-made video doing the exact same thing i described. it's burned in my eyes by now! ;)
jvincent wrote on 10/28/2006, 1:14 AM
To Jeff (Using ARTBEATS matte)

Track 1 : insert matte video, choose MULTIPLY MASK as COMPOSITING MODE for this track then insert SONY MASK GENERATOR in the track FX.

Track 2 : insert the fire video corresponding to the matte, then set track2 as a CHILD of the track 1

Track 3 : insert your backgorund video.

Then ... press PLAY
Jeff Waters wrote on 10/28/2006, 3:47 AM
Awesome, thank you! I think I'm starting to understand how this works now. I think I followed this to the letter and I still only see the background video.

Do I need to set anything special in the SONY MASK GENERATOR settings?

Thanks,
Jeff
jvincent wrote on 10/28/2006, 9:52 AM
Norhing to change on the sony mask genrator , just insert it with default setting.
Order of the tracks is very important.
On top : matte (trk1)
then fire (trk2)
and on the bottom the background (trk3).
Your problem is as if background was on top on track1 or as if track2 was muted.
Do you make your test with a new empty project ?
Vincent