9

1196 Chapter 9: Surface Modeling
ULoftSurface
SelectNURBSobject. >Modifypanel>CreateSurfaces
rollout > Dependent Surfaces group box > U Loft
Select NURBS object. > Modify panel > NURBS toolbox >
Create U Loft Surface button
A U loft surface interpolates a surface across
multiple curve sub-objects. The curves b ecome
U-axis contours of the surface.
UsingmultiplecurvestocreateaULoftsurface
Tips
• A U loft can be an extremely dense surface.
To i mpro ve pe r for m a n c e w h i l e w ork i n g w i t h
viewports, set the surface approximation (page
1–1239) for viewports to Curvature Dependent.
• You can speed up U loft creation by making
sure that the curves you loft have the same
number of CVs in the same order (that is, the
cur ves point in t he same direction). Also, CV
curves have a performance advantage over
point curves.
• Turning off display of dependent sub-objects,
including the U loft itself, also speeds up
interactive performance when you create a U
loft. The default keybo ard togg le for dependent
sub-object display is
Ct rl +D (the Keyboard
Shortcut Override Tog g le (page 3–872) button
must be on.)
Closed U lofts
Automatic Cur ve Attachment
When you create a U loft, you can select curves
that are not a lready sub-objects of the a ctive
NURBS mo del. You can select another curve or
spline (page 1–266) object in the scene. When you
select that curve, it is automatically attached to the
currentobjectasifyouhadusedtheAttachbutton.
Wa rn in g : If the curve you attach is a sub-object of
anotherNURBSmodel,theentiremodel(thatis,the
curve’s parent NURBS object) is attached as well.
Asyoumovethemouseoveracurvethatisnot
part of the active NURBS object, the cursor
changes shape to indicate you can pick the curve,
but the curve is not highlighted in blue.
Procedures
To create a U l of t surfa ce:
1.
In a NURBS object that contains at least
two curves, tu
rn on U Loft.
2. Click the firs
tcurve.
3. Click addition
al curves in succession.