9

CV Curve Sub-Object 1153
Create a dependent point curve on surface
(page 1–1175).
Create a dependent surface offset curve (page
1–1167).
Create a dependent surface edge curve (page
1–1177).
CV Cu rve S u b-O b je ct
Selec t NURBS o b je ct. > M odify panel > Create Curves
rollout > CV Curve button
Select NURBS ob ject. > Modify panel > NURBS toolbox
>CreateCVCurvebutton
CV curve sub-objects are similar to object-level
CV c urves (page 1–1110).Themaindifference
is that you can’t give CV curves a renderable
thickness at the sub-object level.
Dra wing T hree-Dimensi onal Cur ves
WhenyoucreateaCVcurve,youcandrawitin
threedimensions.Therearetwowaystodothis:
• Draw In All Viewports: T hi s toggle lets you use
any v iewport to draw the curve, enabling you
to draw three dimensionally.
•Using
Ct rl to dr ag CVs: While you draw a
cur ve, you can use the
Ctrl key to drag a CV
offoftheconstructionplane.
With the
Ct rl –key metho d, further mouse
movement lifts the latest point off the construction
plane.Therearetwowaystousethis:
•Click-drag.Ifyouholddown
Ct rl and a ls o
hold down the mouse button, you can drag to
change the height of the CV. The CV’s location
is set when you release the mouse button.
This method is probably more intuitive.
•Click-click.Ifyou
Ct rl +click and then release
the mouse button, the height changes as you
dragthemouse.Clickingthemouseasecond
time sets the CV’s location.
This method is less prone to repetitive stress
injury.
WhileyouareoffsettingtheCV,areddotted
lineisdrawnbetweentheoriginalCVonthe
construction plane and the ac tual CV offset
fromtheplane.Youcanmovethemouseintoan
inactive viewport, in which case the software sets
the height of the CV using the CV’s Z axis in the
inactive viewport. This lets you set the heig ht of
the CV with accurac y.
Snaps (page 2–41) also work w hen you change the
height of a CV. For example, if you turn on CV
snapping, you can set a CV to have the same height
as another CV by snapping to that other CV in an
inactive viewport.
Procedure
To create a CV curve sub-object:
1.
Turn on CV Cur ve.
2. In a viewport, click and drag to create the first
CV, as well as the
first curve segment. Release
the mouse button to add the second CV. Each
subsequent location you click adds a new CV to
the curve. Righ
t-click to end curve creation.
Note: If you beg
in the curve by clicking without
dragging, this also creates the curve’s first CV.
However, if you release the mouse button more
than five pixe
ls away from where you initially
pressed it, this creates an additional C V.
While you are creating a CV curve, you can
press
Backspace to remove the last CV you
created, and
then previous CVs in reverse order.
If Draw In All
Viewports is on, you can draw in
any viewpor t, creating a 3D curve.