Selecting Objects Individually

Selecting objects individually is the default selection mode. Any time AutoCAD prompts you to Select objects: to create a selection set, the cursor crosshairs change to what is referred to as the pickbox.

The size of the pickbox is used to determine how close you need to be to an object in order to select it. To select an object, it must be within or touching the pickbox. By default, objects that are within the pickbox are previewed by highlighting the objects so that they become thicker and darker or lighter depending on the screen background color (see Figure 7-3). This selection preview feature provides you feedback regarding what object will be selected before you pick with your mouse so that you don’t pick the wrong object unintentionally.

Picking an object adds it to the current selection set and highlights it. See Figure 7-4.

You also get feedback at the command line informing you that one object was found:

Select objects: 1 found

Select objects:

AutoCAD stays in the selection mode until you press the <Enter> key without selecting anything to accept the selection set. This allows you to continue to add to the selection set by selecting more objects. As objects are selected, AutoCAD prompts you if the object was found and keeps a running tally of how many total objects are part of the current selection set:

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Select objects: 1 found, 2 total

Select objects:

You can enter U<Enter> in response to the Select objects: prompt to undo, or deselect, the last object selected. If you have more than one object selected, you can enter U<Enter> repeatedly to deselect multiple objects in the order they were selected.

If you try to select an object and you miss because the object isn’t within the pickbox, you may automatically be put in what is known as implied windowing mode, depending on whether it is turned on or not.

Implied windowing is turned on and off on the Selection tab of the Options dialog box shown in Figure 7-2. If Implied windowing mode is on, AutoCAD automatically initiates the Window option. The Window option is discussed in detail a little later in this section. For the time being, you can hit the <Esc> key to exit the window selection mode and return to selecting objects individually.

Toggling Between Adding and Removing Objects from a Selection Set. It is possible to toggle between adding and removing objects from a selection set using the A (Add) and R (Remove) selection set options. If you type R<Enter> in response to the Select objects: prompt, AutoCAD enters the Remove object mode, and the prompt changes to Remove objects:. Objects you then select are removed from the selection set so that they are no longer highlighted. AutoCAD stays in the Remove object mode until you enter A<Enter> in response to the Remove objects: prompt to switch back to Add object mode. Switching to Add object mode changes the prompt back to the familiar Select objects: prompt.

Using the <Shift> Key to Add to a Selection Set. When selecting objects individually, it is possible to change the selection mode so that you must use the <Shift> key when adding objects to the current selection set. If you select the Use Shift to add to selection check box in the Selection modes area on the Selection tab of the Options dialog box (see Figure 7-2) so that it is turned on, you must hold down the <Shift> key when selecting more than one object. When the Use Shift to add to selection mode is on and you try to select more than one object without using the <Shift> key, the first object is deselected so it is no longer highlighted. By default, the Use Shift to add to selection mode is off.

Selecting Stacked and Overlaid Objects. It is possible to easily select overlapping objects either by picking the Selection Cycling button on the AutoCAD status bar shown in Figure 7-5 or by using the <Ctrl>+W keyboard combination.

When selection cycling is turned on and you try to select an object that overlaps one or more other objects, AutoCAD displays a list of all the overlapping objects that you can select from, so you can select the desired object. When you pass your cursor over an object in the list, AutoCAD highlights the object in the drawing so you know which object in the list it is associated with, as shown in Figure 7-6.

Select the object from the list, and it becomes part of a new or existing selection set.

Selecting Multiple Objects

Oftentimes, you need to select more than one object when modifying a drawing. Suppose you need to erase a large portion of your drawing—you don’t want to have to pick each object individually. Doing so would be very time-consuming. Fortunately, AutoCAD provides a number of selection set options that expedite the process of selecting multiple objects. All these options are entered via the keyboard in response to the Select objects: prompt. The following sections explain each of these selection set options.

W—Window Option. The Window option allows you to define a rectangular window selection area by prompting you to pick two corner points as shown in Figure 7-7.

By default, the windowed area is shaded a semitransparent blue color to make it obvious which objects will be selected before the second corner point is picked. This selection preview feature helps you avoid the unintentional selection of objects.

Using the Window option, only objects that are completely within the window boundary area are selected. Objects that cross the window boundary are ignored (see Figure 7-8).

C—Crossing Option. The Crossing option allows you to define a rectangular window selection area by picking two corner points similar to the Window option, as shown in Figure 7-9.

To distinguish between the Window option and the Crossing option, the Crossing option window boundary is dashed (see Figure 7-9), whereas the Window option window boundary is solid (see Figure 7-7). In addition, the Crossing option windowed area is, by default, shaded a semitransparent green color (see Figure 7-9) instead of the default blue color used with the Window option (see Figure 7-7).

The major difference between the Crossing option and the Window option is that the Crossing option will select objects that cross over the rectangular window boundary in addition to the objects that lie completely within the window boundary area (see Figure 7-10).

Implied Windowing. As mentioned earlier in the section “Selecting Objects Individually,” it is possible to initiate the Window, Crossing, or Lasso option automatically by relying on a feature called implied windowing. Implied windowing can be turned on and off on the Selection tab of the Options dialog box shown in Figure 7-2.

When Implied windowing is on, you can initiate the Window, Crossing, or Lasso option by picking an empty space in your drawing so that no objects fall within your pickbox in response to the Select objects or prompt. If you pick and release the mouse button, AutoCAD interprets the pick point as the first corner point of a rectangular window area and prompts you to select the second corner point as follows:

Specify opposite corner:

This is where it gets interesting. If you move your cursor to the right of the first pick point, you initiate the Window option—the window boundary outline is solid, and the default shade color is blue (see Figure 7-7).

If you move your cursor to the left of the first pick point, you initiate the Crossing option—the window boundary outline is dashed, and the default shade color is green (see Figure 7-9).

In addition to the implied Window and Crossing options, it is also possible to select objects using an implied Lasso option. This option allows you to select the objects you want to by holding the mouse button down after clicking in an empty space in the drawing and dragging a lasso around the objects as shown in Figure 7-11.

WP—Window Polygon Option. The Window Polygon option allows you to define a polygonal window area using multiple pick points so that you can select multiple objects in a complex drawing that you might not be able to select using a simple rectangular window. When you enter the WP option, AutoCAD prompts you for the first polygon point and then prompts you for line endpoints until you press <Enter> as shown in Figure 7-12.

Similar to the Window option, the Window Polygon option selects only objects that are completely within the window boundary area. Objects that cross the window boundary are ignored (see Figure 7-13).

CP—Crossing Polygon Option. The Crossing Polygon option works similarly to the Window Polygon option. It also allows you to define a polygonal window area using multiple pick points except that, like the Crossing option, objects that cross the polygon window are also selected. When you enter the CP option, AutoCAD prompts you for the first polygon point and then prompts you for line endpoints until you press <Enter>, as shown in Figure 7-14.

As noted, the Crossing Polygon option selects objects that cross over the polygon window boundary in addition to the objects that lie completely within the window boundary area (see Figure 7-15).

F—Fence Option. The Fence option allows you to define a multisegmented fence line that selects everything it crosses, similar to the Crossing option. When you enter the F option, AutoCAD prompts you for the first fence point and then prompts you for additional fence endpoints until you press <Enter> as shown in Figure 7-16.

The Fence option selects all objects that the fence line crosses over or touches (see Figure 7-17).

Advanced Selection Techniques

The following selection set options provide additional ways to select objects without having to pick any points in your drawing.

All—All Option. The All option selects all the objects in a drawing—even those objects that lie outside the visible drawing window! Because of this, care should be taken when using it. When used properly, it can be a handy way to modify everything in a drawing.

L—Last Option. The Last option selects the last object created in a drawing. For instance, if you draw a line in a drawing and then enter the ERASE command, entering L in response to the Select objects: prompt highlights and selects the line you just drew.

P—Previous Option. The Previous option recalls the last selection set created so that you can modify the same objects again. If no previous selection set exists, AutoCAD displays the following at the command line:

No previous selection set.

Selecting Similar Objects

The Select Similar tool allows you to select an object and then automatically include all of the other objects in the drawing that are of the same type and share the same properties. The easiest way to use the Select Similar tool is to select one or more objects and right-click to display the Edit shortcut menu shown in Figure 7-18, which includes the tool.

You can control which properties are matched when creating the selection set by entering SELECTSIMILAR at the command line. The SELECTSIMILAR command has a Setting option that displays the Select Similar Settings dialog box shown in Figure 7-19 so you can select the properties to filter by.

Mirroring Text

Usually, when you mirror text you want it to retain its original left-to-right orientation so that the text isn’t reversed, as shown in Figure 7-31.

The AutoCAD MIRRTEXT system variable controls whether or not text is reversed when it is mirrored. Setting MIRRTEXT to 1 (on) will cause text to be reversed when it is mirrored, as shown in Figure 7-31. Setting MIRRTEXT to 0 (off) retains the text’s original orientation, as shown in Figure 7-32.

By default, the MIRRTEXT system variable is set to 0 (off).

Rotating and Copying Objects

It is possible to rotate and copy objects using the Copy option. When you select the Copy option, AutoCAD displays the following at the command line:

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Rotating a copy of the selected objects.

You can use any of the methods explained earlier to specify a rotation angle. Figure 7-37 shows the results of using the Copy option and rotating the objects shown in Figure 7-34A 90° from horizontal.

Scaling and Copying Objects

It is possible to scale and copy object(s) using the Copy option. Using the Copy option, AutoCAD displays the following at the command line:

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Scaling a copy of the selected objects.

You can use any of the methods explained earlier to specify a scale factor.

Multifunctional Grips

Some AutoCAD objects, such as lines, arcs, and dimensions, have grips that can perform multiple functions. Hovering your cursor over a grip displays a shortcut menu similar to those shown in Figure 7-46 so you can select the desired command using your mouse or the arrow key on your keyboard.

Controlling Grips

Grips are controlled on the Selection tab of the Options dialog box shown in Figure 7-47.

The different grip features and their settings are as follows:

• Grip size Controls the display size of grips

• Grip Colors... Determines the color of grips in various modes

• Show grips Displays grips on an object when it is selected

• Show grips within blocks Controls how grips are displayed on a block after you select it. If this option is selected, AutoCAD displays all grips for each object in the block. If this option is cleared, AutoCAD displays one grip located at the insertion point of the block

• Show grip tips Displays grip-specific tips when the cursor hovers over a grip on a custom object that supports grip tips. This option has no effect on standard AutoCAD objects

• Show dynamic grip menu Controls the display of a dynamic menu when pausing over multifunctional grips used by polylines and splines

• Allow Ctrl+cycling behavior Allows the <Ctrl> key cycling behavior for multifunctional grips used by polylines and splines

• Show single grip on groups Displays a single grip for an object group

• Show bounding box on groups Displays a bounding box around the extents of grouped objects

• Object selection limit for display of grips Suppresses the display of grips when the initial selection set includes more than the specified number of objects. The valid range is 1 to 32,767. The default setting is 100.

For the best results, make sure that your grip settings closely match those shown in Figure 7-47. Failure to do so can cause some of the examples and exercises in the following sections to behave differently than anticipated.

Selecting Grips

To select a grip, you must place your cursor within the grip box and pick with your mouse. When a grip is selected, it changes color (default = red), and you are placed in Grip Edit mode, as shown in Figure 7-48.

It is possible to select multiple grips by holding down the <Shift> key before selecting the first grip. You can continue to select grips until you release the <Shift> key. In Figure 7-49, two grips have been selected.

To “unselect” all grips that have been selected (default = red), as shown in Figure 7-48, press the <Esc> key once. This changes the grips to the unselected mode (default = blue), as shown in Figure 7-48. To turn off all the grips that are unselected (default = blue), you must press the <Esc> key again. This will result in the object(s) being simply highlighted with no grips displayed.

Grip Modes

After at least one grip is selected (default = red) and you are in Grip Edit mode, as shown in Figure 7-49, the desired grip mode can be selected either at the command line or via the right-click Grip shortcut menu.

The command line approach allows you to cycle through the five different grip modes starting with Stretch mode by pressing the spacebar or the <Enter> key as follows:

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** STRETCH **
Specify stretch point or [Base point Copy Undo eXit]:
** MOVE **
Specify move point or [Base point Copy Undo eXit]:
** ROTATE **
Specify rotation angle or [Base point Copy Undo Reference eXit]:
** SCALE **
Specify scale factor or [Base point Copy Undo Reference eXit]:
** MIRROR **
Specify second point or [Base point Copy Undo eXit]:

Each time you press the spacebar or <Enter>, AutoCAD cycles to the next grip mode in the order shown above, repeating the modes again when it gets back to Stretch mode.

The other option is to right-click with your mouse to display the Grip shortcut menu shown in Figure 7-50.

This approach allows you to go directly to the desired grip mode option without having to hit your spacebar or the <Enter> key multiple times.

Using either approach, the different grip modes work similarly to their traditional modify command counterparts, explained earlier in the chapter, and share most of the same options. Each grip mode shares the following options:

• Base Point Allows you to specify a new base point to use with the current grip mode. By default, the base point is set to the selected grip

• Copy Allows you to create a copy of the selected object(s) to use with the current grip mode

• Undo Undoes the last grip mode operation

• Exit Exits the current grip mode and leaves grips on but unselected

In addition, the Rotate and Scale modes also have a Reference option that works exactly the same as described earlier in the ROTATE and SCALE modify command sections.

After selecting the desired grip mode either at the command line or via the Grip shortcut menu, the different grip mode options can be selected by selecting the first letter of the option at the command line, by selecting the option from the right-click shortcut menu, or by using your arrow keys if you are using dynamic input.

Multiple Choice

Circle the correct answer.

1. Selecting objects first and then selecting a modify command is referred to as what type of editing process?

a. Noun/verb

b. Verb/noun

c. Grip mode

d. Cut and paste

2. A selection set is:

a. A set of commands used to select objects

b. All currently selected objects

c. A group of similar objects

d. None of the above

3. The box that appears at the mouse crosshairs when you are prompted to select objects is called:

a. Grip

b. Aperture

c. Pickbox

d. Window area

4. When you are creating a selection set, you can remove objects by:

a. Typing U<Enter>

b. Holding down the <Shift> key while selecting objects

c. Entering Remove object mode by typing R<Enter>

d. All of the above

5. The difference between the window selection method and the crossing selection method is:

a. A window boundary is a solid line, and a crossing boundary is a dashed line

b. The window method selects only objects inside the boundary, and the crossing method selects objects inside and objects that cross the boundary

c. By default, the window area preview is blue, and the crossing area preview is green

d. All of the above

6. Implied windowing allows you to:

a. Automatically create a window, crossing, or lasso selection

b. Turn off window, crossing, and lasso selection options

c. Turn on window, crossing, and lasso selection options

d. Select objects with your mind

7. The system variable that controls whether text is reversed when it is mirrored is:

a. MIRRORTEXT

b. MIRRTEXT

c. TEXTMIRROR

d. MTEXT

8. To select multiple grips, you must hold down which key when picking the first grip?

a. <Ctrl>

b. <Shift>

c. <Esc>

d. Spacebar

9. Grip modes can be selected via:

a. Command line

b. Right-click shortcut menu

c. Keyboard shortcuts

d. All of the above

10. The keyboard key that turns off (deselects) grips is:

a. <Ctrl>

b. <Enter>

c. <Esc>

d. <Alt>

Matching

Write the number of the correct answer on the line.

True or False

Circle the correct answer.

1. True or False: The traditional approach to modifying objects in AutoCAD is to select the command first and then select the objects to modify.

2. True or False: The traditional approach to modifying mentioned in question 1 is referred to as the noun/verb approach.

3. True or False: It is possible to select more than one grip at a time using the <Shift> key.

4. True or False: The window, crossing, and lasso selection options can be initiated automatically.

5. True or False: It is possible to create a window, crossing, or lasso selection using only one pick point.

6. True or False: The Previous selection option will select the previous object that was added to a drawing.

7. True or False: The displacement distance for the MOVE, COPY, and STRETCH commands is always relative.

8. True or False: Text is always mirrored when you use the MIRROR command.

9. True or False: It is possible to enter a negative rotation angle when using the ROTATE command.

Project 7-1: Classroom Plan, continued from Chapter 6 [BASIC]

1. Open drawing P6-1 from Chapter 6.

2. Draw the floor plan shown in Figure 7-51 using the A-Door and A-Wall layers for the doors and walls. Place the heater on the A-Eqpm layer. The wall next to the heater is 8″ thick; all other walls are 4″ thick. The doors are each 3″-0″ wide, and the heater is 1″-0″ wide. Do not draw dimensions or text.

   

3. Use the MOVE, COPY, and MIRROR commands to place the desks in the configuration shown. Use object snaps and the Polar Tracking and/or Ortho Mode settings to ensure the desks are aligned.

4. Save the drawing as P7-1.

Project 7-2: Socket Head Cap Screws— English Units [INTERMEDIATE]

1. Start a new drawing using the acad.dwt template.

2. Create two socket head cap screws based on the table shown in Figure 7-52. Do not draw dimensions or table.

   

3. Save the drawing as P7-2.

Project 7-3: Motorcycle Head Gasket— Metric [ADVANCED]

1. Start a new drawing using the acadiso.dwt template.

2. Create the following layers:

   Name	Color	Linetype	Lineweight	Description
   Object	7	Continuous	0.60 mm	Object lines
   Hidden	1	Hidden	0.30 mm	Hidden lines
   Center	2	Center	0.30 mm	Centerlines
   Hatch	4	Continuous	0.30 mm	Hatch patterns and fills
   Notes	3	Continuous	0.30 mm	Text and notes
   Dims	2	Continuous	0.30 mm	Dimensions

3. Draw the motorcycle head gasket shown in Figure 7-53 using the appropriate layers.

   

4. Adjust the LTSCALE system so linetypes appear properly.

5. Do not include dimensions.

6. Save the drawing as P7-3.

Project 7-4: Electrical Distribution Panel [BASIC]

1. Start a new drawing using the acad.dwt template.

2. Create the following layer:

   Name	Color	Linetype	Lineweight	Plot/Noplot	Description
   E-Powr-Panl	7	Continuous	Default	Plot	Electrical power panels

3. Set the grid to .5 and the snap to .25, and draw the electrical distribution panel shown in Figure 7-54. Do not draw grid lines. Hint: The grid lines shown are spaced at .5 intervals.

   

4. Save the drawing as P7-4.

Project 7-5: Residential Architectural Plan, continued from Chapter 6 [ADVANCED]

1. Open drawing P6-5 from Chapter 6.

2. Draw the door and window symbols shown in Figure 7-55 using the A-Door and A-Glaz layers.

   

3. Add the walls and place the doors and windows as shown in Figure 7-56 according to the schedules. Use appropriate object snaps to ensure the proper placement of the symbols. Doors and windows that are not dimensioned are either centered on the interior wall or located 3″ from the nearest wall. Hint: Use the Offset option of the XLINE command to locate the door and window symbols.

   

4. Do not draw the door schedule or identifier symbols. Do not draw dimensions or text.

5. Save the drawing as P7-5.