9

1090 Chapter 9: Surface Modeling
be used with their own controls, and lose their
usefulness when you collapse them.
The modifiers with Soft Selection controls treat
NURBSmodelsthesamewaytheytreateditable
meshes. As with editable mesh vertices, CVs are
colored proportionally according to how severely
the region affects them.
If Relational Stack is turned off (see Nonrelational
NURBS Surfaces (page 1–1116)), the Affect
Neighbors togg le can affect all surface CVs, curve
CVs, and points in neighboring sub-objects.
If Relational Stack is on, Soft Selection affects
neighboring sub-objects only if they are at the
same sub-object level.
Soft Selection works with Scale and Rotate as well
aswiththeMovetransform.
NURBS Objects and the UV W Map
Modifier
When you apply a UVW Map (page 1–922)
modifier, it affects the NURBS object the same way
it affects a mesh . If you then collapse the stack,
UVW mapping is still in effect. However, you
can override the mapper for individual surface
sub-objects. Todoso,turnonthesurface’s
Generate Mapping Coords check b ox, if necessary.
Whenthecheckboxison,yougetthenatural
mapping of the surface; when it is off, you get the
mapping from the collapsed UVW modifier.
Tip: Don’t u se UVW Map to assi gn a texture to
an animated surface. The texture will shift as the
surface animates.
NUR B S Sel ection M odif ier
The NURBS Surface Selection (NSurf Sel) (page
1–747) lets you place a NURBS sub-object
selectiononthemodifierstack. Thisletsyou
modify only the selected sub-objects. Also,
selected curve sub-objects are Shape (page 1–262)
objects that you can use as p aths and motion
trajectories.
NSurf Sel can select any kind of NURBS sub-object
except im ports. Each sub-object selection is of one
sub-object level only.
Procedure
To u se a NU R B S sel ect modif ier:
1.
With a NURBS object selected, go to the
Modify panel a nd apply NSurf Sel.
The selection modifier has no controls at the
object level.
2. Click to open the modifier’s hierarchy, and
choose a sub-object level.
The selection modifier has the same select ion
controls you see for the corresponding
sub-object type.
While applying the modifier, you can also select
NURBS sub-objects by name. Turn on the
K eyboard Shortcut Override Toggle button on
the status bar, and then press the
H key. This
displays a version of the Select Objects dialog
(page 1–78) that lists only sub-objects at the
current level. Choose one or more objects in
the list, and then click Select. Press
Ct rl +H to
have the Selec t Objects dialog list only objects
direc tly beneath the mouse cursor.
3. Usetheselectioncontrolstocreateaselection
set of the chosen sub-object ty pe.
With the NSurf Sel modifier, you can select
NURBS sub-objects at any level except imports.
Note: To select point, curve, or cur ve CV
sub-objects,youmustgototheNURBSobjectand
turn on Relational Stack.
Once you have used the modifier to create the
selection, you can apply other modifiers to it. If
the selected sub-object is a curve, you can also use
it as a path or trajectory.