The universal ruler for 2D drafting systems

Abstract

A set of point positioning and measuring techniques, which lets a traditionally trained draftsmen to establish simple analogies with his/her traditional drafting machine and compass, is described. Well-known interactive techniques organized in a manner which we call the “universal ruler” turn out to be very powerful, accurate, and simple to use. The universal ruler combines in a single entity the straight edge, measuring scale, compass, and protractor; it is based on transformations of a coordinate system used to measure the relative position of the graphic cursor. With the aid of five graphic potentiometers and gravity fields, it provides the means to input points at any desired angle and distance from a reference system, and permits the draftsmen to measure distances and angles in his drawing.