Even before the first full-length computer-animated feature film, 1995's "Toy Story" from Disney/Pixar, American audiences have been in love with three-dimensional CG animation and special effects. Also referred to as CGI (computer-generated imagery), animation and other effects rendered using computer equipment are on the technological cutting edge of movie production. But how exactly does this type of technology work from a practical standpoint?
Four Stages to Bring Images to Life
- On the level of feature films, the computer animator's job starts once the story is written, characters are roughed out, and storyboards have been produced to guide the action. Then the process of modeling begins. Character, object and set drawings are used to create 3D models in one of two ways: either sculpted by hand and scanned into the computer, or modeled directly using the computer.
- Next, the models are animated using "avars" (animation variables), which are defined points on the character model that are manipulated in space to show the illusion of movement. Often, avars correspond to bones in the skeletal system or muscles and features on the face. Animators use animation software to set the character in motion by altering the values of the avars.
- The character is then manipulated in a series of poses called key frames, and the computer is used to "tween" or morph the action between frames. Films in the United States generally run at 24 frames per second, creating the appearance of smooth motion. An alternative method that is also frequently used in computer animation is motion capture, in which a live actor's movements are recorded using a video camera and sensors and then mapped onto the animated character using a computer.
- The final stage in the 3D computer animation process is rendering. In the hands of the computer animator, information about avars, models, movements, textures, lighting and shading are translated into a final image or frame of film. Of course, none of this would be possible without some very sophisticated, powerful hardware and software.
Behind the Scenes
Today it's possible for even home computer users to create animation using widely available software. However, in animation schools, you'll have access to much more efficient graphics-specific workstations, often with multiple processors and powerful graphics cards. These workstations are standard in animation careers as well.
At large commercial animation studios such as Pixar or DreamWorks, many such workstations are networked together into a large system known as a "render farm." With the computing power of a render farm, animation software such as Maya is used in conjunction with rendering programs like Mental Ray or Pixar's Renderman and film editing software to create a computer-animated movie in as short a period of time as a couple of years.
For more computer animator information, check out computer animation college programs to get the software and equipment training you'll need to start in the field.