View Full Version : Advise Needed On Huge Project! Hd + Cg To Film

02 February 2008, 10:00 AM
Hello everybody at CG TALK! It is a real deal for me to be asking for advice to the most talented artists in the business!

My intention here is that my little expermient can benefit other filmakers with similar problems, and similar dreams...

Two years ago, I wrote a Sci-fi script for a seven minute short I had in mind for some time. It was kind of orwellian, dealing with social alienation, individual dispair, and some of the old technology vs humans premise that's around in films and literature since the 20's. (even earlier)

It had tons of cinematic and technical challenges, because it was soposed to be sort of a Fritz Lang's "Metropolis" but with new technology.
The movie is Black and white, soundless (dialog is made on inter titles just like in silent pictures) and depicts dark characters against a decaying urban setting.

My idea was to shoot characters in front of a blue screen and incorporate the city as a c.g. element.

Well, as weird as it could sound, I managed to win a Colombian Goverment grant for short production (I live In Colombia, more exactly, Bogota) and was able to hire the best DP around, rent a huge studio and a Sony CineAlta HD camera (F900),
and shot the god damn thing...
Now, I have almost a Terabyte of DPX files and a huge task over my shoulders. I don't have a nickle left (beacause the grant was only for production) so I have to do my own post.
My intended workflow is as follows:

Model, texture, light and animate the C.G. city
Track the camera
Arrange every C.G. element with the real world camera info.
Render out The C.G Plates
Remove Blue Screen
Compose C.G. with real footage
Export to targas, tiff's or cineaon's for 35mm Blowup
See it at theaters! (Got a prearrangment with a theater chain!)

So... What is the problem?

That real life is not like the movies and never anything is easy!
The C.G modelling part is taking forever, but it is almost done. The software I chose to work with is 3D Studio Max.

I am having some problems with the tracking part, because I started using Boujou and Matchmove, and neither one got me right tracking. I used before both these programs on other proyects and they seemed to work just fine. But here, with my HD 1080P sequences...they just went crazy and gave me very erratic results. A friend told me that the thing was that my shots were fixed shots and those programs are designed for complicated hand held shots. So, not very convinced by my friend's info, I made the tracking with the 3DStudio internal tracker. And to tell you the truth, the results don't satisfy me at all.
The characters Do seem to walk on the horizon and all, but the Lens never seems right. HELP PLEASE!

1.Do I have to use traditional artistic perspective theory to manualy track down the camera?
2. Or stick with the max Solution?

Well, i'm just on this fase of the post. I imagine that I will hve millions of other problems later on.

I am planning to do all the compositing on Discreet combustion 4 and remove the blue screen with it's internal chroma keyer. I don't now if I have to use my DPX sequences with the LOG to linear option..should I?
HERE is one of my greatest doubts...The project is intended for output for film and DVD... What is the correct workflow? Should I remove the chroma key converting the color space of my files to linear?...OR SHould I color correct and key in log?..How should I Export the final edit for the 35mm blowup?... Is it true that Gollum wasn't C.G, and was really Peter Jackson on a diet? What the F*&$·&! should I do!! i'm lost here.

IF anyone out there can give me a hand in anyway I wil be forever greatful (and of course will be compensated on the film's credits)

At this point i'm insecure of the technical choices i've made, and want to see other perspectives on the postproduction.

How do I do to never clamp or degrade my footage or plates?

Wich file type is better for this kind of rendering? (The C.G. elements)

I thank you for taking the time to read this long and bizzare PLEDGE, and hope that some of you talented artists can help me.

Overall, I would want to share with you guys out there, that the biggest lesson i've learned doing this proyect, is that risking yourself for your passion...risking yourself for your dreams is the only way in life to be happy.

THANKS AGAIN. Good luck!


02 February 2008, 01:45 AM
sounds like you have another years worth of work ahead of you. . .
but it also sounds like you are totally stoaked on doing this so here are some of your answers. . .I can't answer them all with 100% certainty

As far as tracking goes this can be really tedioius, and really takes a lot of man hours to get this right. . . However it sounds like your shots are lock-offs and therefore should not need tracking software, but really some on-set measurements, camera info. Maybe its just the boujou settings or plates aren't great for tracking. . .
my advice would be to hire someone who likes and is good at it. though a stuednt a hunderd bucks and they will work hours and hours to get their name in a credit and be able to use their work on a demo reel.

Colorspace is always a tricky situation. Linear space is a good choice, but you need to have a good lookup table to visualize this in vid space on your monitor. I would make everything linear, do all your work in linear and then output to cineon log10 for film output...and you will need vid 16 bit output for DVD... .But working in log on your monitor accurately can be a problem.

So as long as you render to a linear-float (or 16bit if you are tight on space) image type you should not loose too much image fidelity. Exr and tiff are good options.

good luck you have a huge task ahead of you..but it sounds like you have the passion to work it out

02 February 2008, 05:19 AM
Hello Friz Dog! You info is very VERY helpful! So i guess I would have to work on LIN and float all the time, doing all the keying, color correction and CG versus Live action matching... HOw do I setup my LUT's I have seen the Kodak tutorial and some other software especific out there on thenet..should I follow those?

Thanks again for your input. YOU WILL BE IN THE CREDITS!


02 February 2008, 08:48 AM
So your shots have some movement? Or absolutely no movement at all?
If they have even the slightest movement, they are no longer lock off shots, and need to be solved as nodal pan. If you have a camera that is sitting on a tripod, but is rotating to follow the action, when you import the footage into Boujou, you need to change it from "freemove" to "nodal" (it's one of the options that comes up when you import the image sequence.) Also a good idea if you have it, to use the focal length of your camera you shot at, and input it in the -edit - focal constraints. Try to initialize it to a value first (put your lens length in) and after if that isn't anygood, constrain it to the value, (I can't remember what it's called, user fixed or something)

If there was any ZOOM when you were shooting, you need to solve as a Variable length.

If the camera was moving even a little bit (not true nodal) meaning there is parallax, but not that much, Boujou, and most software out there, are going to have a heck of a time getting a solve that makes any sense. In this case, there is a couple of things you could try. If you can make an accurate model of the set, (background objects that were actually in you film) you can solve using object based solving, this goes a long way to getting a solve that actually works. (this is boujou 4 and higher)

If you can't do that, then it's off to something like maya live and it's time to do a hand matchmove, in which case if you don't have much experience, you probably will need someone to do it for you, as these can be painfully tedious and difficult, and the more frames, the worse it gets.

If you are dealing with anything beyond 100 frames, I would try a OBJ. based track in Boujou first.

hope it works out.

02 February 2008, 06:49 PM
Im not sure about setting up your own LUTs. . . I've only worked in video 16bit independently and professionally have hade LUTs already created. . .

Perhaps someone else can address this issue.

02 February 2008, 03:27 AM
Hello Guys! I'm posting a frame of my first shot, so anyone out ther can tell me with path should I take to key and camera match. The camera is fixed so one frame I guess will be enough. For keying, i'm thinking on using the combusion internal keyer or keylight with tight masks around each character. This is just one plate. I shot like three or four of these without the props and with other extas to fill up the street. I'm also going to do some C.G. Extras as well. Any input will be rewarded in heaven! (If you bother to go there anyway)


03 March 2008, 07:16 PM
By fixed.... do you mean there is absolutely no movement in the camera?

Ifso, you don't even need boujou, but you can use boujou (4 and above) to line up the camera in relation to your ground plane and export it in order to have your camera and your position lined up when you export it to your animation package.

If there is no motion, then I would go into maya or xsi or whatever, create a grid, export it as an OBJ. (If you don't have the option to export to OBJ, you need to go to the plugin manager and activate / put a checkmark beside objexport (maya) Xsi has it by default. Not sure about other packages.

Import mesh inside of Boujou after you have imported your plate (create user solve checked)
If there is ABSOLUTELY no movment, and it's one frame, you only need to line up the first frame. Go to frame one of your newly created user solve, it should ask you for the lens length, if not, don't worry about it, but if it does, to your best of your knowledge, put the right information in here. You should see something at the top that is a red circle, with a red arrow pointing diagonally down to the right. click that. Click on a point on your mesh and drag it to a feature on your road, then click on another point and pull it until it is where you want it. (your goal is to make the grid look like it lines up properly with the road / ground.) Once the lines on the grid look like the line up with the angle of the line on the road, then you can export 1 frame of your solve to whatever animation package that you use. (export solve) (in the frame options, put frame 1 to frame 1)

Inside your animation package, you need to save another position and rotation key at the end of your animation (sometimes depending on package)

Hope things turn out well.


03 March 2008, 01:10 PM
Colorspace is always a tricky situation. Linear space is a good choice, but you need to have a good lookup table to visualize this in vid space on your monitor. I would make everything linear, do all your work in linear and then output to cineon log10 for film output...and you will need vid 16 bit output for DVD... .But working in log on your monitor accurately can be a problem.

He's very right there. Colourspace can cause all sorts of confusion. If it helps at all, I wrote something ( a while back explaining what I understood of colour space (although this is more designed with film scans and film output in mind)

I don't know how Combustion copes with all of this kind of thing, but I'd definitely recommend working in Linear from a compositing point of view. You'll have to make sure that your CG renders aren't having some kind of gamma conversion done on them, too. And that all of your textures are in Linear first.

In terms of a custom viewer lookup, I just had a play with a LogLin node in Shake, and came up with the following numbers which give a result that's vaguely viewable. Please don't use this for anything other than viewing, though....!

I've got here:
Black: 95
White: 757
NGamma: 1.854
DGamma: 1.7 (this is the default. If the default in Combustion is 1, like it is in Fusion, leave it there)
Softclip: 50

This will give something reasonable for viewing Log images. (When working in Linear, you'll want to have the viewer LUT also convert from Lin to Log first.)

CGTalk Moderation
03 March 2008, 01:10 PM
This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.