Copyright Goodheart-Willcox Co., Inc. Chapter 16 Visual Style Settings and Basic Rendering 419 create a true display of the silhouette edge of a 3D model. For the 2D Wireframe visual style, the DISPSILH variable can also be set in the Visual Styles Manager palette. The variable is controlled by the Draw true silhouettes property in the 2D Wireframe options category. Setting this property to Yes turns on silhouettes. Controlling Surface Smoothness The smoothness of curved surfaces in hidden, shaded, and rendered displays is controlled by the FACETRES system variable. This variable determines the number of polygon faces applied to the model. The value can range from .01 to 10.0 and the default value is .5. This system variable can be changed by typing FACETRES or by changing the Rendered object smoothness setting in the Display resolution area of the Display tab in the Options dialog box. Refer to Figure 16-2. For the 2D Wireframe visual style, the variable can be set in the Visual Styles Manager palette. The Solid smoothness property in the Display resolution category controls the variable. Figure 16-4 shows the effect of two different FACETRES settings. FACETRES Type FACETRES FACETRES setting ISOLINES setting DISPSILH setting Figure 16-2. The ISOLINES, FACETRES, and DISPSILH values can be set in the Options dialog box. A B Figure 16-3. A—The HIDE command used when DISPSILH is set to 0. Objects are displayed faceted. B—The HIDE command used when DISPSILH is set to 1. Facets are eliminated and only the silhouette is displayed.