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1238 Chapter 9: Surface Modeling
Inter face
Relational Copy—The cloned object is the same
typeastheoriginal. Iftheoriginalobjectwasa
dependent object, the clone includes copies of the
parents. For example, when you clone a Blend
surface, the clone remains a Blend surface and its
two paren t surfaces are copied along with it.
Because all related sub-objects are copied,
Relational Copy can be time-consuming.
Independent Copy —The cloned object is an
independent CV curve or CV surface. It has
thesameshapeastheoriginal,butitsrelational
dependencies aren’t copied. This method of
cloning uses less time and memory, although
you lose the relational properties. For example,
when you clone a Blend surface, the clone is an
independent CV surface.
Copy as Transform Object(s)—The "clone" is
actually a transform curve or transform surface,
based on the original object and still dependent
on it. This lets you create transform curves and
surfaces based on a rotation and scale as well as
on translation.
Include Parent(s)—(Available only for Independent
Copy or Copy as Transform Object(s).) Tells the
system whether or not to include the parents of
the dependent object. For example, if Include
Parent(s) is on when you clone a blend surface, the
two parent surfaces are also cloned as independent
CV surfaces. If Include Parent(s) is off, only the
onecurveorsurfaceiscloned.Cloningisslower
when Include Parent(s) is on, although quicker
than Relational Copy.
Select By Material ID Dialog
Modify panel > Select NURBS object. > Stack display >
Curve sub-object level > Select By ID button.
This dialog lets you select curve sub-objects by the
material ID number assig ned to them.
Interfa ce
ID—Specifies the material ID you want to select.
Clear S election—When on, replaces the current
selection (if any) by the material ID selection.
When off, adds the material ID selection to the
cur rent selection set.
Curve and Surface
Approx imation
Curve Approxim ation
Modifypanel>Selecttop-levelNURBSobject.>Curve
Approximation rol lout
Although NURBS curves are analy tically
generated, in order to generate and display them
they must b e approximated by line segm ents.