Chapter 1 Introduction to Three-Dimensional Modeling 9 Copyright Goodheart-Willcox Co., Inc. The Visual Style Controls fl yout, Figure 1-10C, allows you to quickly display the drawing in one of 10 different visual styles. The default setting when you start a new drawing with the acad3D.dwt template is Realistic. Use of visual styles is introduced in this chapter and discussed completely in Chapter 16. Isometric and Orthographic Viewpoint Presets A 2D isometric drawing is based on angles of 120° between the three axes. AutoCAD provides preset viewpoints that allow you to view a 3D object from one of four isometric locations. See Figure 1-11. Each of these viewpoints produces an isometric view of the object. In addition, AutoCAD has presets for the six standard orthographic views of an object. The isometric and orthographic viewpoint presets are based on the world coordinate system (WCS). The four preset isometric views are southwest, southeast, northeast, and north- west. The six orthographic presets are top, bottom, left, right, front, and back. To switch your viewpoint to one of these presets, pick the view name in the View Controls fl yout in the viewport controls, as previously discussed. Refer to Figure 1-10B. You can also select one of the presets in the View panel in the Home tab of the ribbon. See Figure 1-12. The presets are also available in the Views panel in the Visualize tab. NOTE NOTE You can also change the viewpoint to one of the orthographic or isometric presets by using the VIEW command to access the View Manager dialog box. Once you select a view, the viewpoint in the current viewport is automatically changed to display an appropriate isometric or orthographic view. Since these presets are based on the WCS, selecting a preset produces the same view of the object regard- less of the current user coordinate system (UCS). A view that looks straight down on the current drawing plane is called a plan view. An important aspect of the orthographic presets is that selecting one not only changes the viewpoint, but, by default, it also changes the UCS to be plan to the ortho- graphic view. All new objects are created on that UCS instead of the WCS (or previous UCS). Working with UCSs is explained in detail in Chapter 4. However, in order to VIEW Ribbon Home View SW Isometric SE Isometric NE Isometric NW Isometric VIEW Ribbon Home View Top Bottom Left Right Front Back NW Isometric SW Isometric NE Isometric SE Isometric Figure 1-11. There are four preset isometric viewpoints in AutoCAD. This illustration shows the direction from which the cube will be viewed for each of the presets. The grid represents the XY plane of the WCS.