Powerful computers and computing capability have enabled    realism in computer generated imagery.  The animated films made today are realistic to a fault. For instance, Shrek 3.0 has been wildly popular because of the life like characters which inhabit the movie.

3D animation basically consists of   generating depth in 2D objects by various means. Lighting and shading is a powerful way to provide depth to objects and characters. At first the model of the object is created using a number of polygons. The density of polygons or the number of polygons for a given area defines the smoothness of an object. In applications like 3D video games where real time response is more important than faithful reproduction, the polygon density is obviously less. In applications such as a animated movie, realism of scenes take primary importance. The complexity of the objects requires a high polygon density.

Once the objects have been modeled, they have to be imparted motion or they have to be animated. Finally the animated objects which are essentially 3D in nature have to be converted to 2D. This process is called rendering. More the polygon density, more time it takes to render an object. It is often required to combine video and 3D images. This process is called compositing. Rendering process is one of the most important in generating a 3D image. A small bit of a movie   lasting just a few seconds can take days to be rendered. Render farms and piping are phrases associated with 3D animation.   Mental Ray is a renderer provided as a part of Soft image and Maya 3D packages. It is also gaining in popularity among other 3D developers.  Renderman is a renderer used by Pixar and some large film production companies, for development of feature films.

A number of operations are involved in creating 3D animations. The    three  most  popular software commercially available  for   3D modeling , lighting and shading   are Maya, 3ds Max and Soft image .Each of the software has its  strength and tools to address various requirements of 3D design and development.

Maya   was originally developed by Alias which has now merged with Auto desk. The developers of Maya claim its tools have superior capabilities for production of 3D animated movies.

3ds Max is also   a Auto desk product, originally from Discreet. Due to its high availability and competitive cost, 3ds Max claims to be the most popular 3D software.  It has an excellent game engine and   is extensively used for video game development.

Soft image 3D software is a part of Avid. The developers of this software claim mixed pipeline management leading to more efficiency, less time for development and uniquely suited for game development.

3D computer generated imagery has caught the imagination of the public. US based movie moguls are spending hundreds of millions of dollars to create realistic feature films. These in turn are grossing many millions of sales. The 3D computer graphics industry is therefore growing in leaps and bounds. Features like natural hair, skin and human expressions are being refined and polished, to give   life like appearance to animated objects.