Modelling 3D shaded solids of arbitrary shape using an edge-oriented algorithm

A fast hidden-line eliminating algorithm is introduced which enables creation of 3D shaded images. The algorithm also supports set operations on bodies. It deals only with solids bounded by planar patches (curved surfaces are approximated by polyhedra). This makes it possible to implement a simple shading technique. Bodies of arbitrary shape, both convex and concave, can be built by using such operations as translation and rotation of a polyline or polygon. The algorithm is designed to be able to run even on personal computers. The CPU time for an IBM AT is in the minute range for scenes composed of 400–500 faces. The program package can thus be used effectively in those cases when shaded images are not very complicated, short processing time is of primary importance and there is no need for pictures of “realistic” quality. Possible fields of application are animation, technical drawings and simulation.