8

CV Curve 1113
from the plane. You can move the mouse into an
inact ive viewport, in which case the software sets
the height of the CV using the CV’s Z axis in the
inactive viewpor t. This lets you set the height of
the CV with accurac y.
Snaps (page 2–38) also work when 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 C V by snapping to that other CV in an
inactive viewport.
Procedure
To creat e a NURBS CV curve:
1.
Go to the Create p anel.
2. Turn on Shapes, and choose NURBS
Curves from the drop-down list.
3. Tur n o n CV Cu r ve.
4. In a viewport, click and drag to create the
first CV, as well as the first curve segment.
ReleasethemousetoaddthesecondCV.Each
subsequent location you click adds a new CV to
the curve. Right-click to end curve creation.
Note: If you begin the curve by clicking without
dragging, this also creates the curve’s first CV.
However, if you release the mouse more than
five pixels away from where you initially pressed
it, this creat es an additional CV.
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 viewp ort, creating a 3D curve.
To lift a CV off the construction plane, use
theCTRLkeyasdescribedearlierinthistopic
under "Drawing Three-Dimensional Curves."
As with splines, if you click over the curve’s
initial CV, a
Close Cur ve dialog (page 1–1230)
is displayed. This dialog asks w hether you
want the curve to be closed. Click No to keep
the curve open or Yes to close the curve. (You
canalsocloseacurvewhenyouedititatthe
Curve sub-object level.) When a closed curve
isdisplayedattheCurvesub-objectlevel,the
initial CV is displayed as a green circle, and a
green tick mark indicates the curve’s direction.
5. Adjust the curve ’s creation parameters.
6. (Optional) To add a new NUR BS curve
sub-object,youcanturnofftheStartNew
Shape check box, and t hen repeat the preceding
steps.
Interf ace
Thecreationparametersarethesameforboth
point cur ves and CV curves.
Rendering rollout