Creating 3D Geometry - AutoCAD 2011 and AutoCAD LT 2011: No Experience Required - page 858

Copy the box you just made and move it in front of the back wall,
and then select the copy to expose its grips. Use Ortho mode, key-
board input, or the Move grip tool to ensure that the box is moved
along the x-axis only.
8. Turn on Polar Tracking, and then select each of the four outward-
pointing triangular grips along the perimeter and move them 1 ″ (25
mm) toward the inside of the box (see the left image of Figure 16.31).
Click the triangular grip on the back of the box, and drag it until the
box extends all the way through the back wall (see the right image of
Figure 16.31).
9. Switch to the 3D Wireframe visual style and turn on the Selection
Cycling tool in the status bar if it's not already.
10. Using the Subtract Boolean function, subtract the block-out from the
frame. Switch back to the Conceptual or X-Ray visual style, and your
window should look similar to Figure 16.32.
11. Create a new layer named A-GLAZ-3DOB, give it a light blue color
such as 151, and make it current.
12. A polyline can be drawn only in the XY plane, but a 3D polyline can be
drawn along any axis. Click the 3D Polyline button in the Draw panel,
enter 3DPOLY ↵ at the command line, or choose Draw ➢ 3D Polyline
from the menu bar.
13. Turn on the Midpoint running osnap, and then draw the 3D polyline
using the midpoints of the frame's four, 4 ″ (100 mm)-wide inner
corners.
Switch to the 3D Wireframe visual style and freeze the A-WALL-
EXTR-3DOB layer if you have trouble locating the midpoints. Be sure
to switch back to the Conceptual or X-Ray visual style and thaw the
layer when you are done.
14. Use the Extrude tool to extrude the glazing 0.25 ″ (6 mm). If you have
trouble selecting the 3D Polyline, enter L ↵ to use the Last option at
the Select Objects: prompt. Your kitchen window should look like
Figure 16.33.