28 AutoCAD and Its Applications—Advanced Copyright Goodheart-Willcox Co., Inc. If polar tracking is on when using the Axis endpoint option, you can rotate the cylinder axis 90° from the current UCS Z axis and then turn the cylinder to any preset polar increment. See Figure 2-9A. If the polar tracking vector is parallel to the Z axis of the current UCS, the tooltip displays a positive or negative Z value. See Figure 2-9B. Polysolid The polysolid primitive is simply a polyline constructed as a solid object by applying a width and height to the polyline. Many of the options used to create poly- lines are used with the POLYSOLID command. The principal difference is that a solid object is constructed using POLYSOLID. When the command is initiated, you are prompted to select the start point or enter an option. By default, the width of the polysolid is equally applied to each side of the line you draw. This is center justifi cation. Using the Justify option, you can set the justifi cation to center, left, or right. The justifi cation applies to all segments created in the command session. See Figure 2-10. If you select the wrong justifi cation option, you must exit the command and begin again. The default width is .25 units and the default height is 4 units. These values can be changed using the Height and Width options of the command. The height value is saved in the PSOLHEIGHT system variable. The width value is saved in the PSOLWIDTH system variable. Using these system variables, the default width and height can be set outside of the command. The Object option allows you to convert an existing 2D object into a polysolid. AutoCAD entities such as lines, circles, arcs, polylines, polygons, and rectangles can be converted. The 2D object cannot be self intersecting. Some objects, such as 3D poly- lines, cannot be converted. Once you have set the fi rst point on the polysolid, pick the endpoint of the fi rst segment. Continue adding segments as needed. The Undo option allows you to remove the last segment drawn and continue from the previous point without exiting the command. To complete the command, press [Enter]. POLYSOLID Ribbon Home Modeling Solid Primitive Polysolid Type POLYSOLID PSOLID A B Figure 2-7. A—A circular cylinder. B—An elliptical cylinder. A B Figure 2-8. A—A cylinder is drawn inside of another cylinder using the Axis endpoint option. B—The large cylinder has a hole after SUBTRACT is used to remove the small cylinder.