Animation techniques

Traditional animation began with each frame being painted and then filmed. Cel animation, developed by Bray and Hurd in the 1910s, sped up the process by using transparent overlays so that characters could be moved without the need to repaint the background for every frame. More recently, styles of animation based on painting and drawing have evolved, such as the minimalist Simpsons cartoons, or the roughly sketched The Snowman.

Computer animation has advanced rapidly, and is now approaching the point where movies can be created with characters so life-like as to be hard to distinguish from real actors. This involved a move from 2D to 3D, the difference being that in 2D animation the effect of perspective is created artistically, but in 3D objects are modeled in an internal 3D representation within the computer, and are then 'lit' and 'shot' from chosen angles, just as in real life, before being 'rendered' to a 2D bitmapped frame. Predictions that famous dead actors might even be 'brought back to life' to play in new movies before long have led to speculation about the moral and copyright issues involved. The use of computer animation as a way of achieving the otherwise impossible in conventionally shot movies has led to the term "computer generated imagery" being used, though the term has become hard to distinguish from computer animation as it is now used in referring to 3D movies that are entirely animated.

Computer animation involves modelling, motion generation, followed by the addition of surfaces, and finally rendering. Surfaces are programmed to stretch and bend automatically in response to movements of a 'wire frame model', and the final rendering converts such movements to a bitmap image. It is the recent developments in rendering complex surfaces like fur and clothing textures that have enabled stunningly life-like environments and character models, including surfaces that even ripple, fold and blow in the wind, with every fibre or hair individually calculated for rendering.

On the other hand, life-like motion can be created by a skilled artist using the simplest of models. A computer is nothing more than a very expensive and complicated drawing tool, as a pencil is a drawing tool. Even if a complex physics-simulating program were created complete enough to exactly mimic the real world, without an animator to guide the imagery produced, the end result may not be emotionally affecting. This is because a significant part of the craft of animation concerns the artistic choices that an animator makes, and of which a computer is incapable.

This guide is licensed under the GNU Free Documentation License. It uses material from the Wikipedia.