Graphics Programs Reference
In-Depth Information
Editing with the 3D Edit Bar
You've seen how a NURBS surface can be set up to add additional CVs, which in turn allow you
to adjust the shape of the surface. But the CVs by themselves allow you to adjust their pull on
the surface only by moving the CVs closer to or farther away from the surface.
The 3D Edit bar gives you more control over the behavior of individual CVs. With the 3D Edit
bar, you can change the strength and direction of the “pull” exerted by a CV.
Try the following exercise to see firsthand how the 3D Edit bar works:
1.
Type
3DEDITBAR
↵.
2.
Select the NURBS surface. Now as you move the cursor across the surface, you see two
red lines that follow the U and V directions of the surface (see Figure 23.52).
FIGURE 23.52
The 3D Edit bar's
U and V directions
are shown by two
red lines.
Red Lines
3.
Click the point shown in Figure 23.52. A Move gizmo appears along with two other fea-
tures called the magnitude handle and the expansion grip (see Figure 23.53).
FIGURE 23.53
The magnitude
handle and expan-
sion grip
Expansion grip
Magnitude handle
The Move gizmo gives you a bit more control over the location of the CV since it allows you
to isolate movement in the X, Y, or Z direction. The expansion grip lets you change the tangency
of the CV, while the magnitude grip lets you control the strength of the CV.
