A procedural interface for volume rendering

The author presents a simple, procedural interface for volume rendering. The interface is built on three types of objects: volumes, which contain the data to be visualized, environments, which set up viewing and lighting, and image objects, which convert results to a user-definable format. A volume is rendered against a particular environment with the results sent to an image object for conversion. By defining volume qualities such as color, opacity, and gradient in terms of user-definable transfer functions, the rendering process is made independent of the data set´s underlying representation