Copyright Goodheart-Willcox Co., Inc. Chapter 3 Viewing and Displaying Three-Dimensional Models 63 Plan Command Options Plan Command Options The PLAN command, introduced in Chapter 1, allows you to create a plan view of any user coordinate system (UCS) or the world coordinate system (WCS). The PLAN command automatically performs a ZOOM Extents. This fi lls the drawing window with the plan view. The command options are: • Current UCS. This creates a view of the object that is plan to the current UCS. • UCS. This displays a view plan to a named UCS. The preset UCSs are not considered named UCSs. • World. This creates a view of the object that is plan to the WCS. If the WCS is the current UCS, this option and the Current UCS option produce the same results. This command may have limited usefulness when working with 3D models. The dynamic capabilities of the view cube are much more intuitive and may be quicker to use. However, you may fi nd instances where the PLAN command is easier to use, such as when the view cube is not currently displayed. Displaying Models with Steering Displaying Models with Steering Wheels Wheels Steering wheels, or wheels, are dynamic menus that provide quick access to view- navigation tools. A steering wheel follows the cursor as it is moved around the drawing. Each wheel is divided into wedges and each wedge contains a tool. See Figure 3-15. The NAVSWHEEL command is used to display a steering wheel, but a quicker method is to pick Steering Wheels from the Viewport Controls fl yout in the viewport controls. The steering wheel drop-down menu on the navigation bar can also be used. All of the steering wheel formats discussed in this chapter can be selected in the drop-down menu on the navigation bar. AutoCAD provides two basic types of wheels: View Object and Tour Building. Most of the options contained in these two wheels are included in the Full Navigation wheel. Each of these three types can be used in a full-wheel display or a minimized format. This section discusses the Full Navigation wheel and the two basic wheels in their full and mini formats. There is also a 2D Wheel that is displayed in paper (layout) space or when the NAVSWHEELMODE system variable is set to 3. The 2D Wheel provides basic view-navigation tools for 2D drafting. PLAN Type Plan NAVSWHEEL Ribbon View Navigate Steering Wheels Type NAVSWHEEL WHEEL Toolbar Navigation Bar Steering Wheels ZOOM PAN ORBIT REWIND CENTER WALK UP/DOWN LOOK CENTER ZOOM ORBIT REWIND FORWARD LOOK UP/DOWN REWIND A B C Figure 3-15. A—Full Navigation wheel. B—View Object wheel. C—Tour Building wheel.