Sunday, November 05, 2006

The Manufactured Image: Color, Tone & Texture

As we have seen in plenty of examples the deft use of color and detail are vital to the creation of an integrated artistic image. Handle them poorly and you are playing from a handicap from the start.

The task and asset tree in hand drawn animation is a much simpler system (generally) than CG. The entire image is thought out in workbook. Workbook is where you go from an approved storyboard for a scene and translate that into all the things needed to actually produce that scene for the film. This usually includes a rough color version of the scene. Along with this art comes call outs for specific assets and tasks. Workbook is basically the bible for the scene. It defines everything from color to layout to animation to FX to whatever (the art side) and every asset is identified, given a name and a task (the production management side). So from the workbook stage you would have the callouts for these basic assets:

Background line (traditional or CG. hand drawn made by one artist, CG by modelers & layout staff)
Animation line (anything that moves. Multiple artists create the line based on character, task, etc.)
Foreground line (traditional or CG)
Background color (painting or cel)
Animation color (cel)
Foreground Color (painting, more commonly cel)

More after the jump…

Assets like animation line are usually handled by a larger number of artists, but the end deliverable (from the standpoint of color/detail/etc/) is unified and simplistic- namely line drawings. The background, foreground and animation line finals are put together into a basic line composite. This is often what you see in ‘behind the scenes’ features on DVDs. Here’s a small example from Beauty & the Beast.

beauty_and_the_beast_work.jpg (click to enlarge)

Increasingly the backgrounds are being made in CG with models and 3d cameras. This has it’s own structure and task heirarchy, but the asset focus again is on line only. The Cg models are used to create line drawings without color usually. With cel shading being more common now this may change, but not many folks are making hand drawn big budget animation anymore. Thus the evolution of the process of integrating CG assets into traditional pipelines has kinda frozen for the time being.

Anyhow, at this line composite stage what you usually have is all lines, no colors. A background painting may already be in progress to define the background color. The look of this would be determined by the workbook color key. Anyhow, now a colorist goes back to the workbook and figures out the colors for the scene- specifically the cel colors for moving items (animation) and foreground elements. They’ll do this with an eye toward the rough color key for the scene that was made for the workbook. Once the colorist has defined the final colors for the whole image then new color tasks are assigned. The background is painted by one artist. The animation line is colored by another and the foreground by another. Animation line may be made up of several different line assets (per character, etc.) and thus the coloring tasks may fall along individual assets. (one artist colors Gaston’s line, another colors Belle’s line, etc.) But the color callouts for the whole scene all come back to one place- the colorist’s color call outs based on the workbook. The whole thing never strays very far away from the workbook and it is usually worked in context. The pool of tasks is fairly shallow and perhaps most importantly- individual asset color, detail and texture are defined generally once the entire animated scene is assembled in line form. Thus color is finalized with almost all of the information about staging already defined. Color, detail and texture can now be created to serve the overall staging of the scene. It’s all right there with no guesswork involved. In fact for most of the assets there is really no other way to do it until after the line has been assembled. So it only makes sense that the result of this system would be more cohesive (allowing that the artists involved are good at their jobs). So color, detail and texture (including “lighting” even thought lighting is just another form of color control) are all handled within a short section of the overall asset & task pipeline. First they are defined as a whole in workbook and then, after line assets have been assembled, colored as a whole to match the defined layout and animation. This is of course a somewhat simplified view of the system, but it is generally on target for most typical scenes.

CG has a much more wide spread asset and task structure. The whole concept of workbooking in CG films is still not well defined. Some do it, others don’t although by now most have some form of workbook in their systems. Some who do workbook don’t bother much with color and use workbook only as a way of translating 2d story images into CG camera data. Assuming a Cg film finds it’s way around the initial workbook challenge and they manage to define color, staging, assets, etc., the tasks only get more widely flung.

Currently most CG sets are made up of many sub assets. To meet scheduling demands it is difficult to allow one artist to build an entire set. It often would take too long. So the set is broken down into the parts that make it up. A chair, a desk, a sofa, a room, decorations, etc. By breaking up the task load you can have many assets in development in parallel. So now instead of having a single layout artist create the line drawing for the living room, you have 10 modelers creating models of pieces in the room. Then you have 10 material/shading artists creating the materials. And then 10 texture painting artists creating the textures. Each sub asset comes with it’s own concept art for shape, form, material, texture and color. And each stage for each sub asset is approved or revised in isolation. It’s very rare to review the textures of one asset (the table) while seeing it next to another asset (the sofa). And even more rare to review and approve them all as a whole in the context of the entire set. And it pretty much never happens within the context of any camera data at all. So you see the set colors, materials, textures and details all in pieces- and then never through an actual camera from the show. They’re designed as a whole, but approved and reviewed in isolation. It’s like looking at a jumbled picture of of someone’s body parts instead of a picture of the person. It’s all there, but it’s all broken up.
So after all the individual assets are modeled, have materials and textures applied, and after they’re all assembled into one file you have your background set. But it’s loaded with all kinds of different color and textures. All based off the original set design, but still done in pieces. It doesn’t have any lights added yet, though. So now it goes to a lighter. This person will create the master lighting recipe for the set- a lighting solution that looks good from most angles within the room. If they’re lucky they have some rough camera data to work from based on all the scenes that use this set. Most aren’t lucky. Once it arrives at the master lighting artist’s desk the materials and textures are pretty much set. So they go from design drawings for the set (outside the context of any one scene) to try and make it look good overall. Again- none of this is happening in the context of any one scene at all. The whole color, texture and detail development part of the pipeline is happening ‘offline’. As I have said before, this is no small distinction. This is only the background set. The characters are undergoing their own similar chain of development, as well as all the props and moving set pieces, etc.

The first time you see the animated characters, the background set, the props and all the pieces put together is usually in scene lighting- towards the end of the pipeline. By the time you get here you find that most of the color system is set- practically in stone. Contrast this to the traditional paradigm where at the same stage of assembly very little of the color and detail system is set. For typical Cg productions at this stage the character’s colors and materials have been approved months ago. The colors and textures of each piece that makes up the background set were approved long ago. The master lighting model for the scene has been approved a long time ago. The basic cameras and staging were approved ages ago (not counting minor tweaks in post animation layout). Currently is it only common to have animation working in parallel with scene lighting. So the very first artist to see everything all together is looking at months and months of approved colors, materials, textures, layout staging and base lighting. They’re also looking at most of the schedule and budget already having been spent. They cannot send anything back except in the most dire of occasions. And even then they need to sell it up the chain of command. Send backs at this stage are expensive. Never mind the time element involved because by the time a scene gets to scene lighting most of the schedule is gone and a production is often crunching. The end result is this- the first artist to see and have the whole scene assembled before them has the least amount of authority, time and budget to make it work as a whole.

So compare the two systems. One has fewer artists involved in creating color choices and most of the color choices occur pretty much in concert and at approximately the same time. The other has a wide array of artists involved where color & detail decisions are isolated, incremental and separated by significant gaps of time. All things being equal- great individual artists, equal budgets, etc. which one do you think will yield more cohesive and integrated results artistically?

Once again I stress that these are simplistic generalities, but they are not wholly inaccurate ones. What can be done to fix this? Well, there are no simple answers. You cannot ignore the technological, production and scheduling realities that drive so much of the CG feature film economy. You can’t make the Cg system just be the same as the hand drawn one- it’s not that easy and it won’t work. But you can rethink how you do some things, shift some things around and try things in different ways. And you can use your strengths (ie: technological solutions) to address your weaknesses. In the final installment of this series I propose some ideas that have been knocking around in my head- some experimental, some not so much. Some won’t work, others might. We’ll see.

1 comment:

Keith Lango said...

original comments here...