Sunday, September 19, 2010

A Preview of the 3D Process

The process of creating in 3D requires that you model or shape objects in a scene, give
them color and light, and render them through a virtual camera to make an image. In
essence, you create a scene that tells the computer what objects are where, what colors
and textures they have, what lighting there is, and what camera to use; it’s a lot like directing
an actual production, but without all the actor tantrums over bottled water.
Instead of a canvas on which to paint or copy and paste images, you have a 3D space—
an open area in which you define your objects, set their colors and textures, and position
lights as if you were setting up for a real photo shoot. CG is actually remarkably analogous
to the art and practice of photography and filmmaking.
Photographers lay out their scene by placing the subjects to form the frame. They light
the area for a specific mood and account for the film stock and lens they use and for the
colors of the scene. They choose the camera, film, and lenses according to their desired
result. They snap a picture, develop the negative, and print it to paper. Through this
process, a photo is born.
Once you build your scene in 3D using models, lights, and a camera, the computer
renders the scene, converting it to a 2D image. Through setup and rendering, CGI is born.
And with a little luck, a CG artist is also born.
Rendering is the process of calculating lights and shadows, the placement of textures
and colors on models, the movement of animated objects, and so on to give you a sequence
of 2D pictures that effectively “shoot” your virtual scene. Instead of an envelope of 4 × 6
glossy prints, you get a sequence of 2D computer images (or a movie file like a QuickTime
or AVI [Audio Video Interleave] file) that sit on your hard drive waiting to be seen, and
invariably commented on by your know-it-all friends.
And that, in a nutshell, is the CG process. It requires planning and patience, as CG follows
conventions that are so different than those for painting programs and image editors.
Its work flow is entirely based in building, arrangement, and relationships. But it is an easy
work flow to pick up and eventually master. And it can be done by anyone with the desire
and the patience to give it a try.
Fairly soon, you will begin to see CG as a bigger part of the everyday computing environment,
as we are seeing with image editors and digital-video editing software now.
The more familiar you are with it, whether with Autodesk Maya or another package, the
greater your part in the computing future. The day will soon be on us when we can
custom-make our own environments for our 3D Windows desktops.


Although Maya can be used to produce remarkably lifelike 3D still images, most Maya
artists also work with a fourth dimension, time. That is, most Maya art is animated.
Simply put, animation is change over time. A solid foundation in animation involves
understanding the simulation of something changing over a period of time. Underlying
all animation, from paper flipbooks to film and on to Maya, is the following principle:
when we see a series of rapidly changing images, we perceive the changing of the image
as continuous motion.
In creating CG animation yourself, you have to create scene files with objects that
exhibit some sort of change, whether through movement, color shift, growth, or other
behavior. But just as with flipbooks and film animation, the change you are animating
occurs between static images, called frames, an analogy with film. You define the object’s
animation using a “timeline” measured in these single frames.
You’ll learn more in the section “Basic Animation Concepts” later in this chapter.

The Stages of Production

The CG animation industry has inherited from the film industry a work flow, or pipeline,
a way of doing things that consists of three broad stages: preproduction, production, and
postproduction. In film, preproduction is the process in which the script and storyboards
are written, costumes and sets are designed and built, actors are cast and rehearsed, a crew
is hired, and the equipment is rented and set up. In the production phase, scenes are taped
or filmed in the most efficient order. Postproduction (simply called “post”) describes everything
that happens afterward: the scenes are edited into a story; a musical score, sound
effects, and additional dialogue are added; special visual effects may also be added. (In a
film that has special effects or animation, the actual CG creation is usually completed in
post but may have started in the preproduction phases of the film or project itself.)
Although the work performed at each stage is radically different, this is a useful framework
for understanding the process of creating CG as well.


Preproduction for a CG animation means gathering all reference materials, motion tests,
layout drawings, model sketches, and such together to make the actual CG production as
straightforward as possible.
Since the CG artist must define 3D scenes in the program, it is essential to have a succinct
plan of attack for a well-organized production. The more time spent planning and
organizing for CG, the better. Entering into production without a good plan of attack is
not only going to cause you trouble, it will stunt the growth of your project.
In the real world, preproduction is part of every CG animation project. For the tutorial
projects in this book, you’ll work with sketches and other files supplied on the accompanying
CD as your preproduction. Even for these tutorials, however, you’re encouraged to
gather as much information as you can about the objects you’ll create, even more than what
is presented to you. As with disappointing movies with terribly flawed preproduction stages,
a poorly thought-out CG production will invariably end in headaches and wasted time.

The Script

To tell a story, CG or not, you need to put it in words. A story need not contain dialogue
for it to benefit from a script. Even abstract animations can benefit from a highly detailed
explanation of timings and colors laid out in a script. The script serves as the initial blueprint
for the animation, to lay forth the all-important intent. It is then fleshed out.

The Storyboard

A storyboard is a further definition of the script. You break the script into scenes, and
then you break those scenes into shots. You then sketch out each shot on a panel of a storyboard.
The panels are laid out in order according to the script to give a visual and linear
explanation of the story. Storyboards are useful for planning camera angles (framing a
shot), position of characters, lighting, mood, and so on. Even rudimentary boards with
stick figures on notebook paper are useful to a production.

The Conceptual Art

Conceptuals are the design elements that are needed for the CG production. Typically, characters
are drawn into character sheets in three different neutral poses from the front, from
the side, and from an angle called a 3⁄4 view. Some are even sculpted into clay for better
reference. Color art can also be created of the various sets, props, and characters to better
visualize the colors, textures, and, later on, the lighting that will be needed. Props and sets
are identified from the script and boards and sketched out into model sheets. The better the
conceptual art is visualized, the easier it will be to model, texture, and light everything in CG.


Production begins when you start creating the models from the boards, model sheets, and
concept art. You model the characters, the sets, and the props, and you assign textures
(colors, patterns). The animators take the models and animate everything according to the
boards and script. The sequences are rendered in low quality for dailies and checked for
accuracy and content.
CG production itself has an involved number of steps that are usually defined by the
needs of the production. We’ll peer into 3D work flow in the next section, but to make a
long story short, 3D scenes are created, lit, and animated in the production phase. Most
of the CG techniques you’ll learn in this book are part of the production phase.


Once all the scenes have been set up with props and characters and everything is animated,
postproduction can begin. Postproduction for a CG project is similar to postproduction
for a film. This is where all of a CG film’s elements are brought together and
assembled into final form.


All CG scenes need to be rendered to their final image or movie files. Again, this is the
process by which the computer calculates how everything in the scene should look and
displays it. It is a process that makes great processing demands on your computer, usually
requiring the full attention of your PC, and it can take a good amount of time. As you’ll
learn throughout this book, decisions you make in creating the objects in a scene can
make a big difference in how the rest of the process goes.
You can render one scene while another scene is in production, but working on a system
that is rendering is not advisable unless you’re using a dual-processor machine with
plenty of memory. When everything is rendered properly, the final images are sorted and
the assembly of the CG project begins.
compositing, editing, and adding sound; you will find a multitude of books on these topics
available for further study.


Quite often, CG is rendered in different layers and segments and needs to be put back
together. In a particular scene, for example, multiple characters interact. Each character
is rendered separately from the others and from the backgrounds. They are then all put
together in compositing, the process of bringing together scene elements that were created
separately, to form the final scene. Maya makes this process easier with Render Layers
Compositing programs such as Shake and After Effects not only allow you to compose
CG elements together, they also give you some additional control over color, timing, and a
host of other additions and alterations you can make to the scene. Compositing can greatly
affect the look of a CG project; professionals consider it an integral part of CG creation.


The rendered and composited CG footage is collected and edited together to conform
to the script and boards. Some scenes are cut or moved around to heighten the story.
This process is essentially the same as in film editing, with one big difference: the amount
of footage.
Live-action filmmakers shoot much more footage than is needed for the film, to make
sure they have adequate coverage for all their scenes and to leave extra room for creativity
in the editing. The editor and the director sift through all the scenes and arrange them to
assemble the film in a way that works best with what they have shot. A typical film uses a
small fraction of all film or video that is shot.
Because CG creation and rendering is much more time-consuming and expensive to
generate than shooting most live action, scenes and shots are often tightly arranged in
preproduction boards so not much is wasted, if any. The entire production is edited with
great care beforehand, and the scenes are built and animated to match the story, almost
down to the frame. Consequently, the physical editing process consists mostly of assembling
the scenes into the sequence of the story.


Sound design is important to CG. Viewers like to associate visuals with audio. A basic
soundtrack can add a significant punch to a simple animation by helping provide realism,
mood, narrative, and so on, adding a greater impact of gestalt to the CG.
Sound effects such as footsteps are added to match the action on the screen; this type
of sound is also known in film as foley sound. Music is scored and added to match the film.
Again, this is much the same procedure as in film, with one exception. In the event that a
CG project requires dialogue, the dialogue must be recorded and edited before CG production
can begin. Dialogue becomes a part of the preproduction phase as well as post.
This is because animators need to hear the dialogue being spoken to match the lips of the
characters speaking, known as lip-synch. Quite often, the dialogue or musical score inspires
a character’s actions or body language as well.

(article compiled from the internet.)

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