Computer graphics displays in the neurosciences are classified into three categories: anatomical structures, physiological waveforms, and statistical summaries. The capabilities required in a line drawing system to present neuroscience displays are smooth rotation and translation of 3D structures, simple line rejection, orthographic projection, and flexible interactive hard copy capable of drawing dots. The general purpose computer is available to refresh the CRT. A simple graphics processor with the necessary capabilities is defined and its unique features are discussed.

A matrix transform processor (MTP) for an Evans and Sutherland LDS-2 graphics system has been designed and built at the University of North Carolina. The MTP performs all the important functions of a matrix multiplier, clipper, and perspective divider. Because of fast division logic in the MTP, the clipping and perspective division algorithms are straightforward and the machine is quite simple. One processor handles all the functions; it is not necessary to pipeline the processes. The worst-case line processing time is about 10 μs.