Autocad tutorial part:3(visual reference)

The method we just used to create the freehand sketch is known as the interactive

method, where we use the cursor to specify locations on the screen. This method is

perhaps the fastest way to specify locations on the screen. However, it is rather difficult

to try to create a line of a specific length by watching the displayed coordinates. It would

be helpful to know what one inch or one meter looks like on the screen while we are

creating entities. 

AutoCAD® 2012 provides us with many tools to aid the construction of

our designs. For example, the GRID and SNAP MODE options can be used to get a

visual reference as to the size of objects and learn to restrict the movement of the cursor

to a set increment on the screen.

The GRID and SNAP MODE options can be turned ON or OFF through the Status Bar.

The Status Bar area is located at the bottom left of the AutoCAD drawing screen, next to The second button in the Status Bar is the SNAP MODE option and the third button is the

GRID DISPLAY option. Note that the buttons in the Status Bar area serve two functions:

(1) the status of the specific option, and 

(2) as toggle switches that can be used to turn

these special options ON and OFF. When the corresponding button is highlighted, the

specific option is turned ON. Using the buttons is a quick and easy way to make changes

to these drawing aid options.

Another aspect of the buttons in the Status Bar is these

options can be switched on and off in the middle of another command.

Option Buttons

GRID ON

1. Left-click the GRID button in the Status Bar to turn ON the GRID DISPLAY

option.  (Notice in the command prompt area, the message “<Grid on>” is

also displayed.)

2. Move the cursor inside the graphics window, and estimate the distance in

between the grid lines by watching the coordinates display at the bottom of

the screen.

The GRID option creates a pattern of lines that extends over an area on the screen.

Using the grid is similar to placing a sheet of grid paper under a drawing. The grid

helps you align objects and visualize the distance between them. The grid is not

displayed in the plotted drawing. The default grid spacing, which means the distance

in between two lines on the screen, is 0.5 inches. We can see that the sketched

horizontal line in the sketch is about 5 inches long.

SNAP MODE ON

1. Left-click the SNAP MODE button in the Status Bar to turn ON the SNAP

option.

2. Move the cursor inside the graphics window, and move the cursor diagonally

on the screen. Observe the movement of the cursor and watch the coordinates

display at the bottom of the screen.

The SNAP option controls an invisible rectangular grid that restricts cursor

movement to specified intervals. When SNAP mode is on, the screen cursor and

all input coordinates are snapped to the nearest point on the grid. The default snap

interval is 0.5 inches, and aligned to the grid points on the screen.

3. Click on the Line icon in the Draw toolbar. In the

command prompt area, the message “_line Specify

first point:” is displayed.

4. On your own, create another sketch of the five-point star with the GRID and

SNAP options switched ON.

5. Use the right-mouse-button and select Enter in the popup

menu to end the Line command if you have not done so.