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1176 Chapter 9: Sur face Modeling
Automatic Reparameterization group
Theradiobuttonsinthisgroupboxletyou
choose automatic reparameterization. With
reparameterization, the curve maintains its
parameterization as you edit it. Without
reparameterization, the curve’s parameterization
doesn’t change as you edit it, and can b ecome
irregular.
None—Do not reparameterize.
Cho rd L e n g t h —Chooses the chord-length
algorithm for reparameterization.
Chord-length reparameterization spaces knots
(in
parameter space (page 3–1082)
)basedonthe
square root of the length of each curve segment.
Chord-length reparameterization is usually the
best choice.
Unifor m—Spaces the k nots uniformly.
A uniform knot vector has the advantage t hat the
curve will change only locally when you edit it.
With the other two forms of parameterization,
moving any CV can change the entire curve.
Replace Surface—Lets you replace the parent
surface. Click a button, then click a surface to
replace the original parent surface.
Edit—Click to display the
Edit Curve on Surface
dialog (page 1–1230)
, which lets you edit the curve
in a two-dimensional (UV) representation of the
surface.
To edit multiple curves on a surface, select more
than one CV curve sub-object on the same surface,
then click Edit.
Rebuild—Displays the
Rebuild CV Curve dialog
(page 1–1237)
to let you rebuild the CV curve on
surface.
Reparam—Displays the
Reparameterize dialog
(page 1–1238)
to let you reparameterize the CV
cur ve on surface.
Poi nt Curve on S urf a ce
Select NURBS object. > Modify panel > C reate Curve s
rollout>DependentCurvesgroupbox>PointonSurf
button
Select N URBS obj ect. > Modify pane l > NURBS toolbox >
Create Point Curve on Surface button
Apointcurveonsurfaceissimilartoaplainpoint
curve,butitliesonasurface. Youcreateitby
drawing rather than project ing from a different
curve. You can u se this curve type for
trimming
(page 1–1082)
the surface on which it lies.
Trimming a surface with a point curve on surface
There are two methods for drawing and editing
curves on surfaces: drawing in a viewport, or
using the Ed it Curve on Surface dialog. The choice
is useful b e cause you draw in two dimensions, with
a mouse or other pointing device, while the curve