8
1108 Chapter 9: Sur face Modeling
Creating and Editing Point Sub-Objects (page
1–1220)
Common Sub-Objec t Controls (page 1–1123)
Editing Point Sub-Objects (page 1–1124)
Editing Cur ve CV Sub-Objects (page 1–1128)
Editing Surface CV Sub-Objects (page 1–1132)
Editing Curve Sub-Objec ts (page 1–1136)
Editing Surface Sub-Objects (page 1–1142)
Note: Like an object-level
NURBS surface (page
1–1102)
, an object-level NURBS curve is a
top-level
NURBS model (page 3–1074)
that can
contain NURBS cur ve, NURBS surface, and
NURBS point sub-objects. A NURBS curve
remains a Shape object u n less you add a surface
sub-object to it; if you do, it converts to a NURBS
surface (without changing its name).
Creating Independent Surfaces from NURBS
Curve Objects (page 1–1116)
You can also create NURBS curve sub-objects by
attaching or importing other objects such as other
NURBS curves or spline shapes.
Attaching and Importing 3ds Max Objects (page
1–1121)
Display Controls for NURBS Models (page
1–1119)
Both NURBS curves and NURBS surfaces have a
DisplayareaintheModifypanel.Thesecontrols
affect which portions of the NURBS geometry are
displayed. Next to the Display area is the button
that turns on the toolbox for creating sub-objects.
Poi nt Curv e
Create panel > Shapes but ton > NURBS Curves > Point
Curve button
Createmenu>NURBS>PointCurve
Point curves are
NURBS curves (page 1–1107)
whose points are constrained to lie on the curve.
Apointcurvecanbethebasisofafull
NURBS
model (page 3–1074)
.
Points lie on the curve they define.
Drawing T hree-Dimensional Curves
When you create a point curve, you can draw it in
threedimensions.Therearetwowaystodothis:
• Draw In All Viewports: This toggle lets you use
any viewport to draw the curve, enabling you
to draw three dimensionally.
•UsingCTRLtodragpoints:Whileyoudraw
acurve,youcanusetheCTRLkeytodraga
point off of the construction plane.
With the C TRL key method, further mouse
move ment lift s the latest point off the construction
plane. There are two ways to use CTRL:
• Click-drag.IfyouholddownCTRLandalso
hold down the mouse button, you can drag
to change the height of the point. The point’s