ipbuker_graph09İİTTÜÜ--SUNY SUNY 20042004--2005 2005 FallFall

Graphic Graphic CommunicationsCommunications

Lecture 9: Introduction to AutoCAD

Assoc. Prof.Dr. Cengizhan Assoc. Prof.Dr. Cengizhan İİpbpbüükerker

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• Start AutoCAD by clicking on the Windows Startbutton (bottom left), then move the mouse to Programs then CAD and Modelling then "AutoCAD Architectural Desktop 2" and click on AutoCAD Architectural Desktop 2. A dialog giving various startup options will be displayed. Select the second option: "Start from Scratch" and click OK.

Starting AutoCAD (1)

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Once AutoCAD has loaded, move the mouse around until you see a crosshair cursor. The AutoCAD window has a number of important features:

1. The standard Windows drop-down menus. 2. The standard Windows toolbar below the

menus, it includes: File-New, File-Open, File-Save, Print and "Find and Replace"(!!).

3. In addition to the standard toolbar there will be a number of AutoCAD specific toolbars: Object Properties, Draw and Modify (there may be others...?).

Starting AutoCAD (2)

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4. View Tabs - these 'tabs' give access to different view of the current drawing. The "model" tab should be selected at present.

5. The command area - this small window (by default) has space for three lines of text - this is where you type commands.

6. The status area, at The graphics area - that's the area where you draw - note the scroll bars and the axis label.

7. the bottom of the AutoCAD window, this includes the current cursor position.

Starting AutoCAD (3)

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Starting AutoCAD (4)

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Command Entry (1)

Typically there are three ways of giving a command!

Not all commands are on the Menus and/or toolbars!

1. Type the command using the keyboard - the command is displayed in the command area.

2. Select the command from a menu. 3. Select the command's icon from a toolbar.

When I want you to type a command in the command area the AutoCAD command will be written like:

This means : type the text (qsave) and then press the Enter key (or the space-bar). type: QSAVE

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Command Entry (2)

When I want you to select a command from a menu, it will look like:

This means : click on the 'File' menu and then 'Save' (which should be one of the items on the 'File' menu). select File - Save

AutoCAD also supports common shortcuts like Ctrl-S for Save!!

When I want you to pick a command from a toolbar, I'll write:

select Save Here I'm trying to cover all the bases by giving you the

command to type, the menu options and showing you what the toolbar icon looks like!

Despite all of the above, I'll probably use a combination of the above like:

select File - Save (or type QSAVE )

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Draw a Rectangle

Select Rectangle (or type rectang ), then type: The text typed is displayed

in the command area at the bottom of AutoCAD's

window.

15,15 415,315 these are absolute cartesian coordinates

Hopefully AutoCAD drew a rectangle, which fits comfortably in the AutoCAD graphics area!? If you can't see the rectanlge, type z [space] a [space] (zoom all) - this instructs AutoCAD to redraw the view, "zooming out" to show all the graphics on the drawing.

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Saving a Drawing

Note that if you type

SAVE , you actually get "Save

As"!!

The quickest way to save is to press Ctrl-

S - this is the same as "qsave".

Select the Save icon from the standard toolbar. The drawing has not been saved before, so AutoCAD will display the SAVE AS dialog box, select the appropriate Drive and Directory (for example: S:\arch\u1234567), type the drawing name (for example TUT1), and then select "OK".

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Draw some Lines (1)

We will now draw some more graphics and then save and exit AutoCAD.

Type LINE

Instead of LINE, you can also type: L this is an "alias" -

which is a short-cut.

The exact positions of these lines is not important.

Move the crosshair to near the bottom-left of the rectangle and click the left mouse button, then move the crosshair to the top-right of the rectangle and again click the left mouse button.

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Draw some Lines (2)

Remember this! If you press after you finish a command, the command is re-

issued.

Press to terminate the command, and then press again to re-start the command!

Draw a line from the top-left to the bottom-right of the rectangle, and then press to end the command.

This will save the drawing and exit AutoCAD - don't PANIC!

Now type: QUIT

You will be prompted to save the changes you've made - click OK.

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Coordinate Systems

AutoCAD is a three dimensional CAD system, so

you can enter XYZ values instead of the XY values

shown here.

When specifying positions you can use Cartesian or Polar Coordinates. Cartesian coordinates are simply a X value, a comma, and a Y value, for example: 100,100. Polar coordinates are a Distance followed by a < symbol and an angle, for example: 10<25. Angles are measured in degrees, with 0 = East and 90 = North. Any of these numbers can have decimal values.

Consider relative coordinates simply as

distances!

The positions specified above are "absolute coordinates", because they specify a particular position. AutoCAD can also use "relative coordinates" to specify a position relative to the current position, for example: @5.6,-3.4 and @16.32<62.

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Snap Modes (1)

A simple way to turn Object Snap ON or OFF, is to click on "OSNAP" in the status Area. To see the various

snap options "right-click" on "OSNAP" (in the status area) and

select "Settings...".

It is often useful to be able to draw something from (for example) the end of another shape. AutoCAD has a large selection of "snap modes" for this purpose. The most commonly used snap modes are "Endpoint" (which snaps to the end of the selected graphics entity) and "Intersection" (which snaps to the intersection of two graphics entities).

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Snap Modes (2)

To get AutoCAD to display the Object Snap Modes toolbar, select "Toolbars" from the "View" menu

and then select "Object Snap".

The object snap modes can either be typed or they can be selected from the standard toolbar

or from the snap toolbar:

To display the "Drafting Settings" dialog, click on the

"horse-shoe" shaped icon on the end of the Object Snap Toolbar.

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Draw an Arc

Select Arc (or type ARC ), then select the midpoint snap mode (or type: MID ) and select the left side of the bottom of the "diamond" polyline you drew before. Then use the midpoint snap to enter points on the right side at the bottom and then the top of the polyline (see figure 2).

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Draw a Rectangle and a Circle

Draw the rectangle by selecting from the draw

toolbar (or type rectang )

Lastly, I want you to draw a rectangle in the diamond shape, another diamond inside that rectangle, a circle inside that diamond and a horizontal and vertical line also inside the last diamond (see figure 3)! Each shape should touch the Midpoints of the previous shape...

Alternatively select the circle icon and then type 2p then pick the points.

HINT: To draw the circle, select Draw - Circle - 2 Points and then (using midpoint snap) pick opposite sides of the inner diamond.

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Setting the Limits and Units (1)

It is normal when using AutoCAD to draw objects full size, so it's usually necessary to reset the drawing limits to (about) the size of the object being drawn (or in the case of a building the building's site). Type:

Alternatively, select Format - Drawing Limits and then

type the numbers shown.

limits 0,0

This sets the drawing "size" to 50x50 metres.

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Setting the Limits and Units (2)

If the coordinates in the status area didn't change

to no decimal places, move the mouse!

Next we need to get rid of the 4 decimal points! Select "Format - Units...", AutoCAD will display the "Drawing Units" dialog. Make sure Decimal is selected in the Units section and Decimal Degrees in the Angles section, then in Unit's Precision, click on the down arrow beside "0.0000" and select "0", and finally select "OK".

This sets the "model space" dimensions. To reset the drawing view to the whole of the (empty) drawing, select the zoom-all icon, which is hiding under the zoom-window icon (on the standard toolbar) - hold the button down and then rest of the zoom toolbar is displayed (or type: Z [space] A [space] ).

Zoom All Zoom Window

Z is the alias (shortcut) for ZOOM. Remember that [space] is the

same as . Move the cursor around now and note that the coordinates are now bigger numbers!

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Let the Drawing Begin!!

This shows us the "drawing area".

Firstly draw a rectangle from 0,0 to 50000,50000, you should remember how to do that from the first tutorial!

Circle "C" is the alias for CIRCLE.

Then draw a circle, centred at 30000,24000 with a 6000 radius. Select circle (or type: C ), then type: 30000,24000 the circle centre 6000 the circle radius

Centre snap

To get AutoCAD to display the Object Snap Modes toolbar,

select "Toolbars" from the "View" menu and then select

"Object Snap".

Next you will draw another circle, with the same centre, but with a 9500 radius. Press: to "recall" the last command. Select the centre snap mode (or type: CEN ), then pick the first circle (NOT the centre of the circle), then type: 9500 the circle radius

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Exploding Objects!

For convenience, in the following section, I'll talk of the "top-right wing" and the "bottom-

right wing". By the "top-right wing" I mean the first rectangles and arc that you drew, and the

"bottom-right wing" is the rectangles and arc in the bottom-right corner!!

Now we need to erase some of the lines we've drawn. When the rectangle command is used the rectangle that is drawn is a "polyline" which means that all the lines that make up the object are joined together, the lines must be "exploded" before any parts of the rectangle can be erased.

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Exploding Objects!

Explode Be aware that explode does not appear to do

anything! It doesn't say - "yes, I've done that" and the display doesn't change, but

AutoCAD will dispaly an error message if it failed to explode the objects.

Select explode from the modify toolbar (or type X which is the alias for "explode") select both the rectangles in the "top-right corner" and then press . If AutoCAD doesn't display any error messages then the explode command worked!

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Erasing Objects

Erase Select erase from the modify toolbar (or type: E ). Click on the right edge of the inner rectangle (from the "top-right" corner), and press . AutoCAD should automatically redraw the area around the erased line.

Now we erase the other line

there!

An alternate way to delete is to click on the object to be deleted and then press the keyboard's "Delete" key. Click on the line in the same place and press "Delete".

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Layers (1)Most CAD systems have some kind of overlay concept. AutoCAD uses layers. Layers are used to separate and structure drawings; layers can be turned on and off (for example to vary the amount of detail in a drawing), and can have linetypes associated with them....

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Layers (2)

Layers icon The current layer is the layer to which new graphics is added. The properties

command (which was introduced in the previous tutorial) cann be used to

change a graphics object's layer (or linetype or colour).

Select the Layers icon or select Format - Layers..., AutoCAD will display the "Layer Properties Manager" dialog. Click on the "New" button and then type CONST (to change the default "layer1" name to something more meaningful), then click on the "Current" button to make this the current layer.

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Draw "Construction" Lines (1)

Line icon Draw a line from the centre of the building: select then line icon (or type L ), and then type:

0,0 0,-17500 @3000,0 terminate the command

Zoom Window

Before continuing, you should "zoom in" to the lines, select zoom-window (or type Z W ), enclose the lines in the selection rectangle.

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Draw "Construction" Lines (2)

Offset Select offset from the Modify toolbar (or type [the letter 'o'] O ), and then type:

The offset command makes it easy to set up a series of grid line or (drawing) construction lines.

250 the offset distance

select the short horizontal line pick a spot anywhere above the line select the new line pick a spot anywhere above it

terminate the command

This should produce one vertical and three horizontal lines.

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Zoom Dynamic

If you don't like the dynamic zoom

command, there's always the scroll

bars...

One of the most powerful of the zoom options is zoom-dynamic, it allows for zooming and panning at the same time. Type Z D or select the command from the zoom flyout (flydown?) shown in figure 8.

AutoCAD should draw the whole drawing, a green (or purple) rectangle showing the current view and the cursor will turn into a rectangle with a X cross at the centre. If you click with the left mouse button you can resize the zoom window's size (click again to fix the new size).

Figure 8 Zoom Dynamic

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Hatching

Hatch icon Create a new layer, called hatch, and make it current, and then select hatch from the Draw toolbar, make sure the pattern type is "Predefined", and set the patern to AR-SAND, set the scale to 2, select "Pick Points", pick inside the two areas, press to end the selection process, pick "OK". AutoCAD should draw lots of dots, almost filling-in the wall area.

Note that the hatch style we are using may appear solid, but it is not! Zooming in will show that hatch is a

"sand" pattern. To have the hatch "solid" simply select the SOLID style

instead of "AR-SAND"...

Finally, you need to erase the three lines you added to close the wall areas so you could hatch them (see figure 15). Use the Layer Controls to turn the "HATCH" layer OFF first. If you accidentally pick the wrong thing, type: R (remove) to remove selections, and then type: A to restart adding selections. Once you've erased the three lines, turn the "HATCH" layer back ON.

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Text (1)

Select Format - Text Style, in the top section of the dialog select "New", click on OK (to accept the default name) then choose a font from the Font Name drop-down list - choose a true-type font (look for the TT icon), for example Arial, set the Height to 10, select "Apply" then select "Close".

Create a TEXT layer, set it's colour and make it current.

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Text (2)

Text icon The Text command can also be used to

add text in MODEL SPACE, but the height of the text must be the text height x the plot scale, for example if you want

the text 5mm high and the drawing at scale 1:100, the height must be 500.

Make sure you're in Paper Space, then select text (or type: MT which is short for MTEXT), you will now enter two points that will define the "boundary" of the text area. When you to type a paragraph of text, AutoCAD will wrap the text to fit inside the boundary! Pick a position below the bottom-left corner of the building, and a second point near the right edge of the 20mm border try to make sure there's enough height for the text...

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Text (3)

Type: Graphic Communications!

You can change the properties of the text (within the dialog box) by selecting the property that you want to alter: select "Graphic" then select the colour drop-down list (it should show "ByLayer" at present), select a colour, then click on "OK" to dismiss the dialog box.

Depending on the way AutoCAD is configured, you may enter the text into a dialog box or the word processor. This section assumes you are using the "Multiline Text Editor" dialog box.

This text is obviously wrong.

Properties icon Select properties, pick the text and press , AutoCAD will display the Modify MText dialog, take a moment to look at the various options available...

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Creating the Plot File

Print icon

Select print or select File - Print (or type: PLOT ), the Plot Configuration dialogue box will be displayed. This complicated dialog box has six areas:

• Device and Default Information • Pen Parameters • Additional Parameters • Paper Size and Orientation • Scale, Rotation, and Origin • Plot Preview

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http://www.fbe.unsw.edu.au/learning/autocad

Reference

AutoCAD 2000 Tutorialsby Jim Plume

Email: j.plume@unsw.edu.au