Crossing Polygon Selection

The Crossing Polygon option can be used in exactly the same way as the Window Polygon option but it has the same selection criteria as the Crossing Window option, i.e. objects will be selected if they fall entirely within or touch the polygon boundary. This option is invoked by typing CP at the "Select objects" prompt.

Note: Lines, polygons and windows drawn using the selection options do not exist as drawing objects. Once the selection has been made they disappear.

Using a Previous Selection

AutoCAD always remembers the last selection set you defined. This is very useful because you may need to make a number of changes using different commands to the same group of objects. In order to re-select the last selection set you can use the Previous option. The previous option is invoked by typing P at the "Select objects" prompt.

Selecting the Last Object

You can select the last object created by entering L at the "Select objects" prompt.

Object Cycling

When drawings become complicated it is sometimes difficult to select the particular object you want because it is either very close to or overlies another object. In such a case it may happen that the other object is selected and not the one you want. Object cycling is designed to overcome this problem. If you make a pick whilst holding the Control (Ctrl) key down, AutoCAD will respond with "". If you continue to pick, each object near the pick point is highlighted in rotation. Just keep picking until the object you want is highlighted, then right-click or , AutoCAD responds "", the required object is added to the selection set and you can continue to select more objects as normal.

Adding and Removing Objects

AutoCAD provides two methods for adding and removing objects to and from a selection set. As you know, objects can be added to a selection set simply by picking them or by using one of the methods outlined above. You can remove selected objects from a selection set just as easily by shift picking. If you hold the Shift key down on the keyboard while picking a selected object, that object will be deselected (removed from the current selection set). You can tell when a selected object has been deselected because it is no longer highlighted. You can remove more than one object at a time by holding down the Shift key while using implied windowing. However, none of the other selection options which require keyboard input will work using the shift pick method.

If you need to remove a more complex selection from the current selection set you should use the Remove option to switch to Remove mode. If you enter R at the "Select objects" prompt, AutoCAD will respond:

Remove objects:

Objects now picked or selected using any of the above methods will be removed from the current selection set. When you have finished removing objects, you can return to Add mode by entering A at the "Remove objects" prompt.

You can use any combination of picking, selection options and add/remove modes to define your selection set. Once you are happy that you have selected all the objects you need, just hit to complete the selection process and to continue with the current command.

When you feel confident with the basic selection tools, have a look at the Advanced Selection tutorial to find out how to use AutoCAD's advanced selection tools for creating complex selection sets.

Tips & Tricks

• When you are picking objects in a complex drawing, use the ZOOM command transparently to make object selection easier. All Zoom options selected from the toolbars are automatically transparent but if you invoke the command from the keyboard you will need to enter 'zoom.