AutoCAD Tip – Using Line Patterns to show real world objects

By Dennis Collin

AutoCAD has had the ability to display patterned lines since its initial versions. These linetype patterns such as dotted and dashed do not relate to real world elements. The intended display is for schematic purposes and although these linetypes can be customised, the patterns will always stretch from the centre of line segments making them unsuitable for real world object display like road markings.

A recent question I was asked was how to get a dashed line to represent line positions on a road? However, due to linetype limitations the dashed lines would not behave as desired.

To get the desired effect, create a block of a widened polyline, a metre long and 0.2 metres wide. This block can then be positioned along a setting out curve and arrayed along the path with the measure constraint spaced with an appropriate gap. The path array in AutoCAD is often missed or forgotten about by users, but it proves very useful in situations where elements need to be copied along and aligned to a curve. Its parametric nature means that if properties need to be changed, select the array and adjust the spacing rules to suit.