AutoCAD has many tools to help you as a designer. Some of these
you may have already used. The properties command gives
you a lot of information about an object you have selected
and allows you change most of them. AutoCAD also has
some commands used specifically for pulling information
from objects.
Most of these commands can be accessed
from the Home > Utilities tool panel. Here is a list of those commands (click on the
icon for more information) :
COMMAND 
KEYBOARD 
ICON 
DESCRIPTION 
Distance 
DISTANCE / DI 

Distance measures the distance and angle between two points 
Radius 
MEASUREGEOM 

Measures the radius of an arc or a circle. 
Angle 
MEASUREGEOM 

Measures the angle between two lines. 
Area 
AREA 

Area Calculates the area and perimeter of objects or of defined areas. 
Volume 
MEASUREGEOM 

Area Calculates the area and perimeter of objects or of defined areas. 
Mass Properties 
MASSPROP 

Mass Properties Calculates and displays the mass
properties of regions or solids. 
List 
LI 

List Displays
database information for selected objects. 
ID 
ID 

ID Point Displays the coordinate values of a location. 
The first one, DISTANCE (DI),
is quite straight forward. It allows you to select two
points on the screen and AutoCAD will tell you the total
distance as well as the changes in X,Y & Z.
Command: DI DIST
Specify first point: <SELECT ANY POINT>
Specify second point or [Multiple points]: <SELECT ANY POINT>
Distance = 12.5107, Angle in XY Plane = 25, Angle from XY Plane = 0
Delta X = 11.3228, Delta Y = 5.3208, Delta Z = 0.0000
MEASUREGEOM is used to for a few options, among them Radius which will measure the radius of a circle or arc. Enter the command and then choose radius from the list on the screen.
With Radius selected, just pick on any arc or circle to have the radius displayed.
AutoCAD is kind enough to give you both the radius and the diameter on the screen  and on the command line:
Command: measuregeom
Enter an option [Distance/Radius/Angle/ARea/Volume] <Distance>: R
Select arc or circle: <SELECT THE OBJECT>
Radius = 3.3780
Diameter = 6.7559
You are left in the command and can select another option like Angle. Now you're asked to select 2 lines and the screen will display the angle between them.
Volume measurements can be used on 3D objects or 2D objects (if you enter a height). You can either select and object or pick points.
AREA is
a command that can be very useful. This can used to calculate
square footage for floors, property lots, or even something
like sheet metal parts. To use this command, you can
type in AREA and
see this on your command line:
Command: AREA
<First point>/Object/Add/Subtract: O
Select objects:<SELECT
AN OBJECT>
Area = 56.7498, Perimeter = 30.6775
The default option is to pick a point on the screen. This
allows you to select the four corners of a room to find
the total area in square drawing units (usually inches).
You can pick as many points as you need and then press
enter when you're done. AutoCAD returns the area and
the perimeter length. If you select the next option (object),
you can select a circle, rectangle, polyline or some
other closed object. You also have the option of adding
to or subtracting from the initial area. You may need
to find the carpeting area of a room, but exclude where
you have tile. Or you may need to add several rooms together.
MASS
PROPERTIES is an option for finding information
about 3D solid objects. You can find out the total
volume and from there calculate the weight based on
volume. AutoCAD also figures out some important engineering
figures for you such as the center of gravity for an
object. This listing shows you all the information
you can get from MASSPROP:
Command: massprop
Select objects: 1 found
Select objects:
 SOLIDS 
Mass: 12.0984
Volume: 12.0984
Bounding box: X: 1.8644  4.1304
Y: 16.1318  18.3978
Z: 0.0000  3.0000
Centroid: X: 2.9974
Y: 17.2648
Z: 1.5000
Moments of inertia: X: 3646.3725
Y: 148.8749
Z: 3722.6569
Products of inertia: XY: 626.0851
YZ: 313.3141
ZX: 54.3957
Radii of gyration: X: 17.3607
Y: 3.5079
Z: 17.5413
Principal moments and XYZ directions about centroid:
Press ENTER to continue: <ENTER>
I: 12.9564 along [1.0000 0.0000 0.0000]
J: 12.9564 along [0.0000 1.0000 0.0000]
K: 7.7653 along [0.0000 0.0000 1.0000]
Write analysis to a file? [Yes/No] <N>: n
This
is a lot of information, so AutoCAD gives you the option
of saving it to a file after it is displayed.
LIST is
an inquiry that gives you some basic information about
a command. This is usually the information that AutoCAD
needs to know about it to keep track of it in its database.
Here is a listing of a line:
Command: LI LIST
Select objects: 1 found
Select objects:
LINE Layer: "0"
Space: Model space
Color: 1 (red) Linetype: "BYLAYER"
Handle = 2fd
from point, X= 9.2042 Y= 13.5272 Z= 0.0000
to point, X= 2.1187 Y= 8.2064 Z= 0.0000
Length = 12.5107, Angle in XY Plane = 205
Delta X = 11.3228, Delta Y = 5.3208, Delta Z = 0.0000
Here are the properties (CTRL+1) for the same line:
Notice that you can get the same information, but also have
the option of changing anything that you need to.
After List, the next option is ID POINT.
This allows you to select anywhere on the screen and
have AutoCAD return the X,Y&Z coordinates for that
point. Here is a listing of ID POINT:
Command: ID Specify point: <SELECT
POINT>
X = 155'2 1/2" Y = 48'9 3/16" Z = 0'0"
(You
can also get this information by selecting a grip and
looking at the status bar.)
OTHER
INQUIRY TOOLS:
Time Displays
the date and time statistics of a drawing. Type TIME.
Status Displays
drawing statistics, modes, and extents. Type STATUS.
Set
Variable Lists or changes the values of system
variables. Type SETVAR.
TIME and STATUS are
two inquiries that give you information about the system,
as opposed to objects.
Here
is a listing of TIME:
Command: TIME
Current time: Wednesday, November 07, 2007 6:00:11:671 PM
Times for this drawing:
Created: Sunday, April 28, 1996 10:11:02:620 AM
Last updated: Tuesday, August 10, 2004 1:24:52:328 AM
Total editing time: 0 days 12:00:49:244
Elapsed timer (on): 0 days 12:00:49:244
Next automatic save in: <no modifications yet>
You
can see the current date, when you last saved and when
AutoCAD will do its next automatic save. And yes, that file has been with me for 8 years.
Here
is a listing of STATUS:
Command: STATUS
120 objects in Drawing1.dwg
Model space limits are X: 0.0000 Y: 0.0000 (Off)
X: 12.0000 Y: 9.0000
Model space uses X: 4.1963 Y: 0.2930 **Over
X: 52.2702 Y: 34.7170 **Over
Display shows X: 9.5333 Y: 7.2543
X: 68.2812 Y: 37.6074
Insertion base is X: 0.0000 Y: 0.0000 Z: 0.0000
Snap resolution is X: 0.5000 Y: 0.5000
Grid spacing is X: 0.5000 Y: 0.5000
Current space: Model space
Current layout: Model
Current layer: "TEXT"
Current color: BYLAYER  3 (green)
Current linetype: BYLAYER  "Continuous"
Current lineweight: BYLAYER
Current elevation: 0.0000 thickness: 0.0000
Fill on Grid off Ortho off Qtext off Snap off Tablet off
Object snap modes: Center, Endpoint, Intersection, Midpoint,
Quadrant,
Extension
Free dwg disk (C:) space: 2797.3 MBytes
Free temp disk (C:) space: 2797.3 MBytes
Free physical memory: 13.6 Mbytes (out of 509.8M).
Free swap file space: 752.0 Mbytes (out of 1246.3M).
As you can see, there is a lot of information here, not
only about your drawing, but about the computer you are
working on.
The
last inquiry, SET VARIABLE (SETVAR),
allows you to change any system variables, or if you
like AutoCAD will list them for you. The details of this
command are not covered in this lesson. You must be VERY
careful when working with system variables. A brief overview
is given in Lesson 48
RETURN
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CONTINUE TO THE NEXT LESSON  47 >
