A Display System for Processing Engineering Drawings

Abstract

The application of computer displays for processing engineering drawings has often been considered but practical systems have been difficult to achieve because of the limited resolution of the display screen and its associated device — the light pen. However, these disadvantages can be offset to some extent by data structure techniques which link the displayed points and lines with their exact dimensional values instead of their truncated screen coordinate values. The essential properties of these structures make it possible to break away from rigid sequential lists of coordinates and devise more natural computer structures to represent the geometry of the drawn part. Again the intrinsic flexibility of these systems is such that, at a slight increase in complexity, it is possible to keep track of a full three-dimensional description of the drawn part and this in turn could form the basis of a comprehensive data bank for design analysis problems concerned with 3D geometry.