Computer rendering of lobster neurons

At Carnegie Mellon University, the PDP-10 and PDP-11 computers have been used to trace thin sections of stained neurons in a lobster swimmeret ganglion, and to reconstruct the global structure of the neuron from the sections. This paper will present two sorts of graphic pictures of the final reconstructed neuron; vector drawings with hidden lines, and shaded raster drawings of the neuron inside a transparent shell representing the outer surface of the ganglion. The hidden line program handles curving cylindrical tubes of varying radii, and shows only the visible contours. The raster program is a modification of Sproul's version of the Watkins Algorithm, and applies Phong shading to both opaque and semi-transparent surfaces. The shaded output is rendered on the Carnegie-Mellon video system.