3ds Max 2012 Bible - Kelly L. Murdock [160]
Reverse
The Reverse button is available only for Spline subobjects. It reverses the order of the vertex numbers. For example, a circle that is numbered clockwise from 1 to 4 is numbered counterclockwise after using the Reverse button. The vertex order is important for splines that are used for animation paths or loft compound objects.
Outline
The Outline button creates a spline that is identical to the one selected and offset by an amount specified by dragging or specified in the Offset value. The Center option creates an outline on either side of the selected spline, centered on the original spline. When the Center option is not selected, then an outline is created by offsetting a duplicate of the spline on only one side of the original spline. To exit Outline mode, click the Outline button again or right-click in the viewport. Figure 12.30 shows an arc that has had the Outline feature applied. In the right image, the Center option is enabled.
FIGURE 12.30
The Outline button creates a duplicate copy of the original spline and offsets it.
Boolean
Boolean operations work with two or more splines that overlap one another. There are three different operations that can happen: You can combine the splines to create a single spline (union), you can subtract the overlapping area from one of the splines (subtract), or you can throw away everything except the overlapping area (intersection).
Cross-Reference
You can also use Booleans to combine or subtract 3D volumes, which are covered in Chapter 27, “Working with Compound Objects.” •
The Boolean button works on overlapping closed splines and has three different options—Union, Subtraction, and Intersection—shown in Table 12.3. The splines must all be part of the same object. The Union option combines the areas of both splines, the Subtraction option removes the second spline's area from the first, and the Intersection option keeps only the areas that overlap.
To use the Boolean feature, select one of the splines and select one of the Boolean operation options. Then click the Boolean button, and select the second spline. Depending on which Boolean operation you chose, the overlapping area is deleted, the second spline acts to cut away the overlapping area on the first, or only the overlapping area remains. To exit Boolean mode, right-click in the viewport.
Note
Boolean operations can be performed only on closed splines that exist within a 2D plane. •
Figure 12.31 shows the results of applying the Spline Boolean operators on a circle and star shape. The first image consists of the circle and star shapes without any Boolean operations applied. The second image shows the result of the Union feature; the third (circle selected first) and fourth (star selected first) use the Subtraction feature; and the fifth image uses the Intersection feature.
FIGURE 12.31
Using the Boolean operations on two overlapping shapes
Mirror
You can use the Mirror button to mirror a spline object horizontally, vertically, or along both axes. To use this feature, select a spline object to mirror and then locate the Mirror button. To the right of the Mirror button are three smaller buttons, each of which indicates a direction—Mirror Horizontally, Mirror Vertically, and Mirror Both—shown in Table 12.4. Select a direction, and then click the Mirror button. If the Copy option is selected, a new spline is created and mirrored. The About Pivot option causes the mirroring to be completed about the pivot point axes.
Figure 12.32 shows a little critter that has been mirrored horizontally, vertically, and both. The right image was horizontally mirrored with the About Pivot option disabled. Notice that the eye spline was mirrored about its own pivot.
FIGURE 12.32
Mirroring a shape is as simple as selecting a direction