Offset

the offset command is one of the most useful commands in AutoCAD it creates a new concentric circle a new parallel line or new parallel curve you can offset an object at a specified distance or through to a specific point let’s try these up start off by opening up the offset examples file
now here we have some basic in very simple contour lines each of them parallel to each other here we have the centerline of a road with some simple rectangular shaped lots
we can use the offset command to add new contour lines to our pond
start the offset command you do that by typing in the word offset
o FF s et
or just enter in the letter o now on the ribbon the offset command is found up here in the modify panel it has its own special button that’s right here in the bottom right
start the command and you have to give a distance this will be the distance from the selected object or the original object to the new object that we’re going to create let’s type in 20 units press ENTER this means that the command is going to create a parallel line that’s 20 units away from the original source line now select object to offset will go with the inside line
autocad will automatically generate a preview of where the new line is going to go
satisfactory just left click and your new line is created now you can see here these two lines are equally distant from each other all the way around its contour they’re parallel
offset command is typically still active whenever you go and use it so let’s start it up again we’ll go with 20 units again press enter select the inside line and there you go now we’re still in it we can pick our line again or a new line and start to offset now you can see here it created two different closed polylines that’s because the distance between this first line and where comes in again is smaller than our offset distance they couldn’t create the line so it creates closed areas where appropriate but that’s okay because that’s what we would want to do in this case
now maybe you don’t want to offset by a specific distance but maybe you want the new line to pass through a specific point so start the offset command again and instead of entering in the distance type then the letter T as you can see here is for the word through because we’re going to select an object and offset it through another point so let’s go up to our center line pick it and now pick the edge of one of these lots you can snap to it with an end point and this puts their new line parallel to the original line but travels through our specific point we can do that again on the other side of the road
and there you go you very quickly created to the center line of your road with your two right aways now let’s do something really fancy say you want to offset the line to a different layer a layer gives an object its
characteristics and it groups similar objects together especially objects that need to look the same or similar to each other we want this edge of our road to be on the road layer not the center so let’s activate the road layer by clicking up here in this box in the layer panel click the black arrow and select Road a road was already set as being active in the file but in case the change had been made that’s how you would do it now any new object that we draw for example line will be drawn on the road layer it’s a solid continuous line that’s magenta in color
so let’s use the offset command again press ENTER and hit the letter L or click on the word layer here in the command line
we have two options current or source current will draw the new object on our current layer source will draw the object on the same layer as the source object you selected and just like it did here with our center line it kept it on the center line but that’s not what we want to do we want to create a parallel line to our center line of our road but we want it to be drawn on the road layer pick the current option and now we’re going to do things the exact same way enter in a distance of twelve press enter and now pick the center line of the road again
and offset it
now we’ve drawn a road that has two lines each lane designated by those lines is 12 units and width so our road is 24 units wide