Home
 ACAD
 Computer Studies
 Graphical
 Knot Making
 Photoshop
 Sudoku


Modify Commands - Part 1

So far we have covered a lot of drawing commands, but sometimes we want to modify what we draw. Maybe we want to lengthen a line, trim it, move it or make a number of copies of the same item. In this tutorial we will go through a number of editing commands that will help you just do this. The modify commands are available through the command line, the modify toolbar (2008) or panel (2009) and modify pull down menu at the menu bar.

This is quite a long tutorial, and it is recommended that you do not only read through it but try out what you learn straight away. If you just read through the whole thing without trying out the various commands, not only will it get boring but you will also probably forget 90% of what you read before you know it! So go get yourself a drink, fire up AutoCAD and enjoy.



Erase

Command for erasing: erase or e

One of the most straight forward editing commands. Just invoke the command, select the item/s you wish to erase and press enter. A quicker method to erase an object would be to first select the object and then press the ‘delete’ button from the keyboard.

Command: e
ERASE
Select objects: 1 found
Select objects: 1 found, 2 total
Select objects: press enter
Move

Command for moving objects: move or m

If you have drawn an object that you wish to move to another position, this is the command to use. Initiate the command, select all the objects you wish to move and press enter to inform the program that you are done with your selection. After this you will be prompted to specify two points on the screen. Those two points will specify the vector by which the objects will move in the direction going from the first point towards the second. So, in other words if the first point you select is (100,80) and the second point is (160,180), the objects will move 60 units to the right on the x axis and 100 units up on the y axis. Try it out by drawing a few objects and moving them around.

Command: m
MOVE
Select objects: 1 found
Select objects: press enter
Specify base point or [Displacement] : click first point
Specify second point or : click second point
You can also specify the displacement of the objects rather than clicking on the screen. Follow the example given below to move an object 50 units to the right and 100 units up. Negative numbers can also be entered to specify movement in the opposite directions, i.e. to the left and downwards. Command: m
MOVE
Select objects: 1 found
Select objects: press enter
Specify base point or [Displacement] : d
Specify displacement <0.0000, 0.0000, 0.0000>: 50,100
You may also notice that the default displacement is set to 0,0,0. There are three zeros, and we have just specified a movement with two numbers. The third is only used when drawing in 3D which will be covered in later tutorials. For now just ignore it. Copy

Command for copying objects: copy, co or cp

The copy command works pretty much like the move command, the only difference is that you end up with two of the same objects, one in the original position and another one in the position specified. Again this is done just like it is with the move command, either by clicking and specifying a vector on screen, or by entering the displacement. Follow the example given to make two or more copies of an object.

Command: co
COPY
Select objects: 1 found
Select objects: press enter
Current settings: Copy mode = Multiple
Specify base point or [Displacement/mOde] : click first point
Specify second point or : click second point for first copy
Specify second point or [Exit/Undo] : click second point for second copy …keep selecting points for more copies as desired
Specify second point or [Exit/Undo] : press enter
Note that if you copy objects by using the displacement option, you will only be able to create one copy of the object/s at a time. You can also set the mode system variable and change it from multiple to single and you will only be allowed one copy at a time even when you use the default option of clicking on the screen. This may be useful to save time in situations where you make a lot of single copies of items but rarely make multiple copies.



Offset

Command for offset: offset or o

The offset command creates a similar copy of the object you apply it to. The copy is offset by a distance that you define. Offset copies of an object are not always exact similar copies, for example if you offset an arc on its outside, the offset copy will be a similar arc but of a larger radius. The following diagram shows an offset arc, line and polyline.

Command line example that will offset an object by 50 units:

Command: o
OFFSET
Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0
Specify offset distance or [Through/Erase/Layer] : 50
Select object to offset or [Exit/Undo] : select object
Specify point on side to offset or [Exit/Multiple/Undo] : click to select side
Select object to offset or [Exit/Undo] : press enter

If you select the through option, then you do not specify a distance by which the object will be offset, instead you pick a point through which the object would pass when offset. The vertical lines in the plan view shown in this example have all been offset using the through option (except for the first line).

The command line history for the offset part of this example is provided for reference:

Command: o
OFFSET
Current settings: Erase source=No Layer=Source OFFSETGAPTYPE=0
Specify offset distance or [Through/Erase/Layer] : press enter to select through option
Select object to offset or [Exit/Undo] : select line
Specify through point or [Exit/Multiple/Undo] : m multiple is activated here to draw multiple copies
Specify through point or [Exit/Undo] : select corresponding point on front elevation
Specify through point or [Exit/Undo] : select corresponding point on front elevation
Specify through point or [Exit/Undo] : select corresponding point on front elevation
Specify through point or [Exit/Undo] : press enter to terminate



Rotate

Command to rotate: rotate or ro

The rotate command allows you to rotate objects for any angle around a specified centre. Follow the example below to rotate an item 45 degrees counter clockwise. If a negative angle is entered then the object is rotated in a clockwise direction. If the ANGDIR system variable is changed from ‘0’ to ‘1’ objects will rotate clockwise when you input a positive angle and anticlockwise when you input a negative angle.

The rotation angle can also be specified on screen rather than input through keyboard.

Command: ro
ROTATE
Current positive angle in UCS: ANGDIR=counterclockwise ANGBASE=0
Select objects: select objects to rotate
Select objects: press enter
Specify base point: specify centre of rotation
Specify rotation angle or [Copy/Reference] <0>: 45

If the copy option is selected, the original object is kept in its original position while an other copy rotated at the angle specified will be created. If the reference option is selected then you will be prompted to select an angle to use as a reference for the object to be rotated at the same angle.


play free sudoku online

Quick links:
Home - Free vectors - pet health care - free stained glass patterns - Free Cross stitch - Free coloring pages - Colorful stained glass patterns for free - Eggart by Candice - Top Cocktail Recipes - Link to us - Paid Links