Graphics Programs Reference
In-Depth Information
Editing NURBS Surfaces
As you've experienced, Maya provides numerous NURBS tools that you'll find useful
when editing your surfaces. In addition to tools for moving CVs, some important func-
tions and tools allow you to add realism to your model. This section gives you a quick
overview of these tools—some you've already used, and others you'll need to try out for
yourself.
The following functions are all accessed through the Edit NURBS menu. Open and
tear off the Edit NURBS menu so it remains open as you follow along. (For more on tear-
off menus, see Chapter 3.)
Project Curve on Surface
The ability to project a curve onto a surface allows you to cut holes in the surface using
the Trim tool (choose Edit NURBS
➔
Trim Tool). It also lets you create, using History,
another surface that is attached, following the outline of your projected curve, as you
saw in the section “Combining Techniques” earlier in this chapter.
Similar to drawing a curve on a surface, projected curves project an existing curve
onto the selected surface. That curve on the surface is now useful for patch modeling as
well as tracing animation paths for objects to follow along a surface. For example, you
can project a curve around a hilly landscape surface and assign a car to animate (drive)
along that projected curve. The car will stick to the surface of the road with ease.
To use Project Curve on Surface, select the surface and the curve to project, and then
choose Edit NURBS
➔
Project Curve on Surface.
Trim and Untrim Surfaces
Trimming
a surface (choose Edit NURBS
➔
Trim Tool) creates holes in the surface using
curves that are either drawn or projected onto the surface.
If you have a surface that has already been trimmed, and it's too late to reverse the
function with Undo, you can use Untrim Surfaces to remove either the last trim per-
formed or all the surface trims. Choose Edit NURBS
➔
Untrim Surfaces.
Attach Surfaces
Attach Surfaces does exactly that—it attaches two contiguous NURBS surfaces along
two selected isoparms. Select an isoparm on the edge of the first surface, Shift+click an
edge isoparm on a second surface, and choose Edit NURBS
➔
Attach Surfaces to create a
new surface from the two. As shown in Figure 5.18, the attach point is along the selected
isoparms.
