Editing Objects with AutoCAD - Section 4

CHAPTER 18: ADVANCED EDITION

Beyond editing operations that could be common to all programs, such as copy or delete, Autocad has an additional set of commands to modify objects that are typical of technical drawing. As you can see below, many of these specialized modification tools facilitate the creation of new objects and the type of CAD drawing.

18.1 Offset

The Offset command creates new objects at a specific distance from existing objects. These are not always duplicates of them. For example, in the case of circles, Offset creates new concentric circles that have, therefore, a radius different from the original circle, but the same center. In the case of arcs, the duplicate may have the same center and the same implicit angle, but more or less arc length depending on the side of the original in which it is placed. Instead, when we use the command with a line object, we get a new line exactly the same as the original, but at the specified distance.
When executing the command, Autocad asks us for the distance to which the new object will be or the indication of a point that it will have to cross. Then request the object to be duplicated and, finally, the side on which it will be placed. However, the command does not end here, Autocad again requests new objects, with the idea that we can create several duplicates at the same distance.
A typical application illustrating this command is the drawing of walls in a house room.

18.2 Symmetry

Symmetry creates, as its name indicates, objects symmetrical to the originals with respect to an axis. Colloquially, we can say that it duplicates the selected objects but as if they were reflected in a mirror. The surface of the mirror, viewed perpendicularly, would be the axis of symmetry.
When we activate the command and make our selection of objects, Autocad asks us for 2 points to establish the axis of symmetry as when we draw a line. The new symmetric object is located at the distance and angle of the axis of symmetry to which the original object is. After defining the axis, we can choose to delete the original or keep it.