CAD DEVICE, OFFSET LINE DRAWING METHOD, AND CAD PROGRAM

摘要

PROBLEM TO BE SOLVED: To draw a parallel line or widened line of a clothoid curve without using any approximation.;SOLUTION: A user designates the clothoid curve that is a reference, and also designates an offset value and the side of drawing the offset line (parallel line or widened line) to the clothoid curve. The CAD device divides the designated clothoid curve at a predetermined dividing pitch p to specify division points. The CAD device determines, for each division point, an offset point which is located on the side designated by the user in a direction vertical to the tangent at the division point concerned and has a distance from the division point equal to the offset value. The offset points are complemented with a straight line to draw the offset line of the clothoid curve. When the offset values differ at one end side and the other end side of the clothoid curve, the difference in offset value between the one end side and the other end side is proportionally divided to the offset value at each division point according to the distance from the one end of the clothoid curve.;COPYRIGHT: (C)2005,JPO&NCIPI