Computer animation can be described as an art form that involves bringing still images to life using computer technology. Animation in this form can apply to images on a computer or to those in film. When is used for movies, this technology is often called computer-generated imagery (CGI).
To create computer animation, a still, or non-moving image, is first displayed. With speed in mind, this image is then replaced with another image. The new image is very similar to the first, but has been changed in some small way. Each subsequent image is changed slightly. This combination of rapid image replacement and slight alteration of images creates the illusion of movement. Though computer technology is used for animation, the technique of creating the look of movement is the same as that used for television and movie animation.
To understand how movement is created with computer animation, consider a blank screen. Now imagine a person drawn on the left side of the screen. Then imagine the screen is blank again, and the next time you see the image of the person, it is positioned just a little to the right of its initial position. Once more, the screen is blanked, and the person is moved a bit more to the right. At a high speed, this slight movement of the image will result in the appearance of smooth movement to the right.
Speed is key to the success of computer animation. To give the illusion of smooth movement, complete images, often called frames, must be shown at speeds of at least 12 images per second. At lesser speeds, the human eye is able to detect a certain amount of jerkiness. Interestingly, however, there is no advantage to showing images at speeds of 70 frames per second or more, as there is no noticeable improvement in movement perception at speeds this high.
When animation is created using conventional hand-drawn methods, it is not uncommon to use 15 frames per second. This is done to economize on the amount of drawings necessary to create the animation. However, computer animation is often used to create more realistic looking images. As such, the use of more frames per second is typically necessary.
A computer and special animation software are necessary for the creation of computer animation. There is a wide variety of animation software on the market today, with prices varying according to the intended use. In general, animation software intended for the novice to enjoy for fun or for simple animation is less costly. Software for more professional animation is not only more expensive, but also more comprehensive. However, even the most basic animation programs are capable of creating some amazing animations.