Creating 3D Drawings - Mastering AutoCAD for Mac - page 521

FIGURE 19.30
Select the Union tool.
Isolating Coordinates with Point Filters
AutoCAD offers a method for 3D point selection that can help you isolate the X, Y, or Z coordi-
nate of a location in 3D. Using point fi lters , you can enter an X, Y, or Z value by picking a point on
the screen and telling AutoCAD to use only the X, Y, or Z value of that point or any combination
of those values. For example, suppose you want to start the corner of a 3D box at the X and Y
coordinates of the corner of the unit plan but you want the Z location at 3´ instead of at ground
level. You can use point fi lters to select only the X and Y coordinates of a point and then specify
the Z coordinate as a separate value. The following exercise demonstrates how this works:
1. Zoom in to the balcony door, and turn on the F-RAIL layer.
2. Click the Box tool near the top of the Tool Sets palette.
3. At the Specify first corner or [Center]: prompt, A-right-click to display the
Object Snap menu, and then choose Point Filters  .XY. As an alternative, you can enter
.XY ↵. By doing this, you are telling AutoCAD that first you're going to specify the X and
Y coordinates for this beginning point and then later indicate the Z coordinate.
You may have noticed the .X, .Y, and .Z options on the Object Snap menu (A-right-click).
These are the 3D point fi lters. By choosing one of these options as you select points in a
3D command, you can fi lter an X, Y, or Z value, or any combination of values, from that
selected point. You can also enter fi lters through the keyboard.
4. At the Specify first corner or [Center]: .XY of: prompt, pick the location at the
base of the wall, as shown in Figure 19.31.
5. At the (need Z): prompt, enter 36 ↵ (the Z coordinate). Metric users enter 92 ↵. The outline
of the box appears at the 36˝ (or 92 cm) elevation and at the corner you selected in step 4.
6. At the Specify other corner or [Cube/Length]: prompt, A-right-click to display the
Object Snap menu again, and choose Point Filters  .XY. Select the other endpoint indi-
cated in Figure 19.31.