Copyright Goodheart-Willcox Co., Inc. 348 AutoCAD and Its Applications—Advanced surfaces. By default, this option is set to No. If this option is set to Yes, you can specify whether tangent edges are shortened to distinguish them from object lines that overlap. The Bend extents option is only available when working with a model that includes a view with sheet metal bends. The Thread features option controls thread displays on models with screw thread features. The Presentation trails option is used to control the display of trails in views created from presentation fi les. Additional drawing view options can be accessed in the Appearance panel of the Drawing View Creation contextual ribbon tab. Selecting the dialog box launcher button at the bottom of the panel opens the View Options dialog box. The options in the View Justification drop-down list determine the justifi cation of the view. The justifi cation refers to how the view is “anchored.” When changes are made to the model, such as a change in size, the view updates based on the justifi cation setting. If the justifi cation is set to Fixed, geometry in the view unaffected by the edit does not change from the original location. If the justifi cation is set to Centered, the geometry updates about the center point of the view. NOTE NOTE The Representation option of the VIEWBASE command is used to create a view based on a model representation and is only available when working with models created in Autodesk Inventor. Working with Drawing Views Creating a base view creates an AutoCAD drawing view object. A drawing view has a view border, a base grip, and a parameter grip for changing the scale. The scale and certain other properties of the view can be edited, as discussed later in this chapter. However, the content of the drawing view cannot be edited. When a base view is created, new layers are created by AutoCAD for the drawing view geometry. The layers are created based on support for the type of geometry represented. Object lines (visible lines) in the view are placed on a newly created layer named MD_Visible. Hidden lines in the view are placed on a newly created layer named MD_Hidden, and so on. The drawing view object is placed on the current layer or on the 0 layer. Additional layers may be created by AutoCAD, depending on the type of model, display style used, and edges displayed in the view. However, the layers are only created to organize the drawing view geometry. The layer properties can be modifi ed to change the appearance of the drawing view geometry, but the geometry cannot be otherwise modifi ed. A B C D Figure 14-5. Display style options available for drawing views. A—Visible Lines. B—Visible and Hidden Lines. C—Shaded with Visible Lines. D—Shaded with Visible and Hidden Lines.