3D computer animation is a type of animation created by making and manipulating a digital model in a three-dimensional (3D) graphics program. There are a number of ways in which this animation can be created, though it often includes keyframing methods somewhat similar to those that have been used in traditional two-dimensional (2D) animation. When a 3D computer animation scene is viewed in its entirety, it is quite likely that separate elements of a scene were animated and rendered individually, and then composited together to create the final animated sequence.
The creation of computer animation usually begins with modeling of the object that will be animated. Modeling is the process by which an object is created in virtual 3D space, using shapes and various tools to create the mesh for an object, and then applying different textures to that object. Once the model is created, then it can be used to create 3D computer animation. Different methods can be used for this type of animation, often depending on the particular program being used, but there are certain approaches to such animation that are common regardless of the software.
One of the easiest ways to create 3D animation is through a process called keyframing. This involves the creation of key frames, which are modified and adjusted to create a final animation. Someone who wants to have a ball roll across a table, for example, might create a first key frame of the ball in the beginning position, change the time of the animation, and then create a second key frame of the ball at the ending position. When the animator previews the animation, the ball will begin at the first key frame, and then move to the second key frame at a speed based on the time at which he or she set the second key frame.
Adding details, such as the rotation of the ball as it rolls and changing the speed of the ball to make it appear more realistic at the beginning and end, would be done in subsequent steps until the final 3D computer animation is complete. This process, of course, becomes more complicated based on the complexity of the object being animated. Animating a person smiling is much more complicated than making a ball roll across a table, but similar methods are still used.
A final scene of 3D computer animation is often created as individual pieces that are then composited together. If a scene consists of a man jumping up and down while a hose sprays water behind him and a dog stands nearby wagging its tail, each element can be created and animated separately. These three pieces will then be rendered, along with a separate background, and the various layers can be composited together to create a final scene.