Flags of our Fathers / Letters from Iwo Jima - Ongoing Q/A Session

Aruna · 05:32 PM

Welcome to another ongoing question and answer session about one of Eastwood's films from last year, Flags of our Fathers. In this Q/A session, I'll be going over some of the problems and solutions that I encountered while compositing the shots for this show. This was my first project with Nuke, as you may find out from some of the screen grabs.

Starting off with some of the simpler A over B comps, here are a couple from the sequence were one of the Marines falls overboard. In this sequence I finished about five or six shots. They involved several CG ships in the background with computer generated wake elements. While we could have used photograph plates for the wakes, it was deemed easier to generate our own CG water. These were all fairly straightfoward, but things like atmospherics and color and shadowing were all dialed in in the comp.

View the Quicktime.

View the Quicktime and the script.

Aruna · May 14th, 2007, 05:19 PM

The next big sequence I worked on was the Green beach landing sequence and battle, which was a fairly big sequence dealing with sand bombs, explosions, cannon blasts, ships sinking, flak elements, strafing hits, you name it. All these shots were done without greenscreen, at the request of the production department. This made our job a little difficult, as every shot had to have some amount of rotoscoping done! I could make do with a number of lumakeys and chromakeys to get the edges of the foreground correct. Because many of the shots were erratic, it was occasionally necessary to create more information so that the foreground could effectively be printed through so the edges were nice.

During the sequence we placed many of the explosions, smoke, flak hits, and Mt. Suribachi (the mountain in the background of many plates) into the plate using Nuke's 3D environment. The leads created Mt. Suribachi and environs, while our compositing supervisor set up a quick Gizmo allowing us to pick and choose among a variety of shrapnel and strafing hits to pepper along the ground.

View the Quicktime.

Aruna · May 14th, 2007, 05:31 PM

One of the sequences near the storming of Mt. Suribachi contained almost a 180 degree spin of the camera.

View the Quicktime and script.

In this shot there were a number of obstacles to overcome. This shot was again, not shot on bluescreen or green, but I actually benefited from not having that. I was able to get decent edge keys against the sky, and used a number of different feather techniques, as well as copious amounts of smoke near the end of the shot to cover up existing smoke that was over the characters. I also added strafing hits, shrapnel, and added some explosions to cover some of the original in the plate. The roto team did an excellent job in providing the necessary masks to complete the shot.

Feel free to ask about any of the techniques I used to overcome the obstacles on the show, and check out my personal site gallery to see more screen shots. I completed almost 20 shots on this show, while on its companion film, Letters from Iwo Jima, I completed close to 45, which were a little simpler, and even more invisible. I'll add the Letters work once the DVD comes out in a week!

gottony · May 14th, 2007, 06:43 PM

Wow. Your nuke scripts are huge. Any chance of some larger breakdowns of your last script so we can see a little closer what you did? Freaking amazing and that was your first nuke project. Awesome. Great job.

SalaTar · 07:17 PM

5 weeks !!!
Damn you need more coffee....;D
whats up with the growing shadow?

MartinL · May 15th, 2007, 01:30 PM

Ah this is so cool!!

Im reaally new to compositing. Im still learning the basics. So i barely know what to ask you.

Like gottony said. Could you give us a larger breakdown on one of the shots?

Anyway. Awesome work mate!!! Big thanks for sharing this with us!!

sorin · May 15th, 2007, 02:39 PM

first of all I would like to say..... woooooooow.
I'm noob in compositing and I don't know nuke, so if I'm not asking too much can u show some breakdowns? that would help a lot, but I know is not a 5 min. task.
thank you.

Aruna · May 16th, 2007, 01:49 PM

Unfortunately, breakdowns for these shots and close-ups of the scripts are unavailable, as the show has been offlined, and I no longer have access to the files to create breakdowns. The only breakdowns I can give are limited to being written!

That said, the majority of these shots were clean plate shots, as there was no bluescreen or greenscreen present, and there were no interactive effects shot at the same time as the actors (no shrapnel, flak, strafing hits, etc). The fx team created a library of elements that we could use and pull from, ranging from large sandbomb hits up to 30 meters high, to small shrapnel hits of a couple feet. The compositors combined all these elements, while color-correcting them to fit the plate, using Nuke's 3D environment. We were able to bring in scene cameras, and align our explosions and hits to the terrain below.

DJMartin · May 16th, 2007, 02:51 PM

Quote:

Originally Posted by Aruna

The fx team created a library of elements that we could use and pull from, ranging from large sandbomb hits up to 30 meters high, to small shrapnel hits of a couple feet.

These videos are so cool, do you know how they created those sandbomb hits? I mean what program, 3d or 2d video?
Thanks, and very well done

Aruna · May 16th, 2007, 03:24 PM

The fx team used Houdini, as well as proprietary DD tools (VoxelB, mentioned in several Siggraph papers and Cinefex, which is now Storm). The majority of the fx (water, shrapnel hits, flak, smoke, etc) were computer generated elements. Occasionally they would render a specific element for a shot, but otherwise the compositors would pull the element they wanted from a library of 3D rendered elements. There were a number of photographically shot explosions as well, which the compers could use in addition to the computer generated explosions.

MartinL · **Me likey -** May 16th, 2007, 05:16 PM

Quote:

Originally Posted by Aruna

Unfortunately, breakdowns for these shots and close-ups of the scripts are unavailable, as the show has been offlined, and I no longer have access to the files to create breakdowns. The only breakdowns I can give are limited to being written!

That said, the majority of these shots were clean plate shots, as there was no bluescreen or greenscreen present, and there were no interactive effects shot at the same time as the actors (no shrapnel, flak, strafing hits, etc). The fx team created a library of elements that we could use and pull from, ranging from large sandbomb hits up to 30 meters high, to small shrapnel hits of a couple feet. The compositors combined all these elements, while color-correcting them to fit the plate, using Nuke's 3D environment. We were able to bring in scene cameras, and align our explosions and hits to the terrain below.

So you tracked the scenes with a 3D tracker and then imported the data in to Nuke before you started to composit the scenes?

And the big sandbomb in the background in 26155.mov looks awesome.
Could you describe how you composited that one in to the live plate? I mean, how did you figure out how the shadow that the dust casts on the ground should look like (shape.. and how the shape gets deformed on the ground)

Thanks!!!!

clicknroll · May 16th, 2007, 05:19 PM

what were you using as main comp app before nuke?
what was your previous experience with nuke before this project? (rating 1 to 10)
how satisfied were you after completing this project, proffesionally speaking? (1to10)

as c&c: the shots look as having absolutely no vfx

great job!

Ajax · May 16th, 2007, 06:44 PM

Hey Aruna,

Long time fan of your work. My question is geared towards the begining of these shots, and how you go about starting the project. Lets say for the Marine that falls overboard, how is this shot presented to you? Do you start with the shot first, then think about what elements will be needed to complete the shot? I've always been curious to know how a compositor preps his or her shots. Do you ask for elements or are they provided to you? Another instance is the roto work that was done for this film and iwo jima lets say you know you need sections that werent shot on greenscreen to be roto'd, how does the communication method work within each department? Im trying to basically understand how you start your compositing process, cheers for the great breakdowns!

Cheers,

Aruna · May 16th, 2007, 09:30 PM

Quote:

Originally Posted by DGZ

So you tracked the scenes with a 3D tracker and then imported the data in to Nuke before you started to composit the scenes?

The 3D tracking was done by the matchmove department. We are able to bring in track data (both camera and object track data) into Nuke, which we can use to line up explosions and other events like the sandbombs and smoke.

Quote:

And the big sandbomb in the background in 26155.mov looks awesome.
Could you describe how you composited that one in to the live plate? I mean, how did you figure out how the shadow that the dust casts on the ground should look like (shape.. and how the shape gets deformed on the ground)

Thanks!!!!

This sandbomb was a combination of a live action plate element and a 3D element. I pulled the live action element from another shot in the sequence, where a sandbomb was actually triggered on set. Using that explosion from the ground and the 3D sandbomb which just sort of appears, I was able to blend the two elements together to give one seamless explosion in motion. The shadow which occurs is a combination of the live action sandbomb shadow as well as some quick rotoscoping to enlarge the shadow as the sandbomb goes higher.

Aruna · May 16th, 2007, 09:36 PM

My main comp app before Nuke was Shake. This was my first production show with Nuke, and I had an accelerated learning curve at the beginning, which was quite tough. I did do some fooling around before I came to DD on Nuke, but it wasn't production work, just figuring out the tools and the way to work around it.

I'm fairly satisfied with the work (there are some things I see in the quicktimes that I wish I could have addressed), and there are more things I felt I could improve after the shots are finalled! I'm much more comfortable with Nuke now, a year and change later.

Quote:

Originally Posted by clicknroll

what were you using as main comp app before nuke?
what was your previous experience with nuke before this project? (rating 1 to 10)
how satisfied were you after completing this project, proffesionally speaking? (1to10)

as c&c: the shots look as having absolutely no vfx

great job!