LESSON 4-1

AUTOCAD TEMPLATE FILES

LESSON 4-2

OBJECT SNAPS - OSNAPS

LESSON 4-3

LINETYPES IN AUTOCAD

LESSON 4-4

AUTOCAD FILE TYPES

LESSON 4-5

USING AND SETTING GRIPS

LESSON 4-6

AUTOCAD'S INQUIRY TOOLS

LESSON 4-7

EXTERNAL REFERENCE FILES - XREFS

LESSON 4-8

INTRODUCTION TO SYSTEM VARIABLES

LESSON 4-9

TABLES

LESSON 4-10

INTRODUCTION TO SET SHEETS

LESSON 4-11

MODIFYING AND CREATING DIMENSIONS

Notes about these lessons:

Most regular text is in burgundy on these pages. Anything you see on AutoCAD's command line is in blue Courier font. Important terms are usually highlighted in red and will also have hyper links attached. Whenever you see a icon, click on it for more information.

Topics covered in this Lesson:

System Variables

INTRODUCTION TO SYSTEM VARIABLES

AutoCAD is a complex program and one of its major selling points is that it is highly customizable. Every user will use AutoCAD differently. Some use icons, some use command line prompts. Each drawing is also different. You may have different text heights, or dimension styles from one drawing to the next. To keep track of these different parameters, AutoCAD uses a large number of system variables to do this. You have already used one system variable: LTSCALE. This could have been changed in the Linetype dialog box, but typing LTS is easier and quicker.

A system variable is a configuration setting that can be changed by the user. Some system variables can not be changed, these are known as read-only variables. Here is an example of each:

Most of AutoCAD's system variables are changeable. This allows for quick customization as well as easier programming.

Once you have used AutoCAD for a while, you may find that it is easier to redefine a system variable than to go through a dialog box to get the same result. In some cases, the only way to make these changes is through the system variable itself. Unfortunately, there are no shortcuts for entering these, you have to either remember them, or have a list nearby. Some of them are quite straightforward as to what they do, but some are rather cryptic and make it difficult for memorization.

**NOTE: In Level 3 (3-D), you were working with system variables to some degree.

Warning: Don't change system variables unless you know exactly what you're doing.

To see a list of all of the AutoCAD system variables, follow these steps:

Command: setvar <ENTER>
Variable name or ?: ? <ENTER>
Variable(s) to list <*>:<ENTER>

It shows you what the settings were for a particular drawing at a specific time. The list also shows you which system variables are read only. For a listing of these in AutoCAD 2007, click here.