AutoCAD provides many options for selecting objects. This section has two parts: The first part deals with object selection methods unique to AutoCAD, and the second part deals with the more common selection method used in most popular graphic programs, the Now till Verb method. Because these two methods play a major role in working with AutoCAD, it’s a good idea to familiarize yourself with them early on.
Selecting Objects in AutoCAD
Many AutoCAD commands prompt you to Select objects: .. \ long with this prompt, the cursor changes from cross hairs to a small square. Whenever you see the Select objects: prompt and the square cursor, you have several options while making your selection. Often, as you select objects on the screen, you will change your mind about a selection or accidentally pick an object you do not want. Let’s take a look at most of the selection options available in AutoCAD, and learn what to do when you make the wrong selection.
Before you continue, you’ll turn off two features that, while extremely useful, can be confusing to new users. These features are called Running Osnaps and Osnap Tracking. You’ll get a chance to explore these features in depth later in this book.
1. First, check to see if either Running Osnaps or Osnap Tracking is turned on. To do this, look at the buttons labeled OSNAP and OTRACK in the status bar at the bottom of the AutoCAD window. If they are turned on, they look like they are depressed.
If they look like this graphic, proceed.
2. To turn off Running Osnap or Osnap Tracking, click the button labeled OSNAP or OTRACK in the status bar at the bottom of the AutoCAD window. When turned off, they will look like they are not depressed.
Now let’s go ahead and see how to select an object in AutoCAD.
1. Choose Move from the Modify toolbar.
2. At the Select objects: prompt, click the two.horizontal lines that comprise the door. As you saw in the last chapter, whenever AutoCAD wants you to select objects, the cursor turns into the small square pick box. This tells you that you are in Object Selection mode. As you pick an object, it is highlighted, as shown.
3. After making your selections, you may decide to deselect some items. Click Undo in the Standard toolbar, or enter U↵ from the keyboard.
Notice that one line is no longer highlighted. The Undo option deselects objects, one at a time, in reverse order of selection.
4. There is another way to deselect objects: Hold down the Shift key and click the remaining highlighted line. It reverts to a solid line, showing you that it is no longer selected for editing.
By now you have deselected both lines. Let’s try using another method for selecting groups of objects.
5. Another situation for selecting objects is to window them. Type W↵. The cursor changes to a Point Selection cursor, and the prompt changes to
6. Click a point below and to the left of the rectangle representing the door. As you move your cursor across the screen, the window appears and stretches across the drawing area.
7. Once the window completely encloses the door but not the arc, click this location and the entire door is highlighted. This window selects only objects that are completely enclosed by the window, as shown.
8. Now that you have selected the entire door but not the arc, press ..1. It is important to remember to press ..1 as soon is you have finished selecting the objects you want to edit. Pressing ..1 tells AutoCAD when you have finished selecting objects. Anew prompt, Specify base point or displacement:, appears. The cursor changes to its Point Selection mode.
Now you have seen how the selection process works in AutoCAD-but you’re in the middle of be Move command. The next section discusses the prompt that’s now on your screen. and describes how to enter base points and displacement distances.
Providing Base Points
When you move or copy objects, AutoCAD prompts you for a base point, which is a difficult concept to grasp. AutoCAD must be told specifically from where and to where the move occurs. The base point is the exact location from which you determine the distance and direction of the move. Once the base point is determined, you can tell AutoCAD where to move the object in relation to that point.
1. To select a base point, hold down the Shift key and press the right mouse button. A menu pops up on the screen. This is the Object Snap (Osnap) menu.
2. Choose Intersection from the Osnap menu. The Osnap menu disappears.
3. Move the cursor to the lower-right corner of the door. Notice that as you approach the comer, a small x-shaped graphic appears on the comer. This is called an Osnap marker.
4. After the x-shaped marker appeared hold the mouse motionless for a second or two. A tool tip appears telling you the current Osnap point AutoCAD has selected.
5. Now press the left mouse button to select the intersection indicated by the Osnap marker. Whenever you see the Osnap marker ,It the point you wish to select, you don’t have to point exactly at the location with your cursor. Just left click the mouse and the exact Osnap point is selected. In this case, you selected the exact intersection of two lines. .
6. At the Specify second point of displacement or <use first point as displacement>: prompt, hold down the Shift key and press the right mouse button again. You’ll use the Endpoint Osnap this time, but instead of clicking the option with the mouse, type E.
7. Now pick the lower-right end of the arc you drew earlier. (Remember that you only need to move your cursor close to the endpoint until the Osnap marker appears.) The door moves so that the comer of the door connects exactly with the endpoint of the arc.
As you can see, the Osnap options allow you to select specific points on an object. You used Endpoint and Intersect in this exercise, but other options are available. this discusses some of the other Osnap options. You may have also noticed that the Osnap marker is different for each of the options you used. You’ll learn more about Osnaps. Now let’s continue with our look at point selection.
If you want to specify an exact distance and direction by typing in a value, select any point on the screen as a base point. Or you can just [email protected] followed by ↵ at the base point prompt; then enter the second point’s location in relative coordinates. Remember that @ means the last point selected In this next exercise, you’ll try moving the entire door an exact distance of 1 unit in a -15° angle. Metric users will move the door 3 units in a 45° angle.
1. Click the Move tool from the Modify toolbar.
2. Type P↵, The set of objects you selected in the previous command is highlighted. P is a selection option that selects the previously selected set of objects.
3. You’re still in the Object Selection mode, so click the arc to include it in the set of selected objects. Now the entire door, including the arc, is highlighted.
4. Now press ↵ to tell AutoCAD that you. have finished your selection. The cursor changes to Point; Selection mode.
5. At the Base point or displacement: prompt, choose a point on the screen between the door and the left side of the screen.
6. Move the cursor around slowly and notice that the door moves as if the base point you selected were attached to the door. The door moves with the cursor, at a fixed distance from it. This demonstrates how the base point relates to the objects you select.
7. Now type @1<45-‘. Metric users should type @3<45-1. The door moves to a new location on the screen at a distance of 1 unit (or 3 for metric users) from its previous location and at an angle of 45°.
This exercise illustrates that the base pint does not have to be on the object you are manipulating. The base point can be virtually anywhere on your drawing. You a also saw how to re-select a group ,of objects that were selected previously, without having to duplicate the selection process.