A new, machine-independent Java Applet, a program that runs in a browser, downloads both byte code and three-dimensional models from a remote Web site and displays them on a local computer. The code is a few hundred kilobytes in size and allows the viewer to control a two-dimensional view of a three-dimensional array, which can be represented by files as small as one byte per node. This code allows both the angle of view and the color map to be controlled by the user.
Representation of three-dimensional models by two-dimensional images is aided by the use of four-dimensional color maps. A three-dimensional color map shows each model value as a specific color, usually as a redgreen- blue (RGB) triplet. A four-dimensional color map associates each value with a four-component set-RGBA—where the A represents alpha, the transparency. This additional component allows vision through parts of the model—the reference or “uninteresting” parts—to the anomalous or “interesting” parts. But this is not a complete solution, since it does not provide depth perception.