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1188 Chapter 9: Surface Modeling
Mirror Axis group
The Mirror Axis buttons control the direction in
which the or iginal sur face is mirrored.
You can’t transform the mirror surface directly
(that would simply transform the mirror surface
and its parent surface at the same time). You
transform it by transforming its gizmo. By using
transforms you can mirror about an arbitrary axis,
rather than using one of the Mirror Axis presets.
When you transform a mirror surface, you are
actually transforming the mirror plane, so Rotate
has the effect of rotating the plane about which
the surface is mirrored. (This is like rotating the
mirror gizmo in the Mirror modifier.)
Tip: A convenient wa y to guarantee that a surface
is symmet rical is to create one side of the surface,
mirror that sur face, and then create a blend
between the two sides.
Offset—Controls the mirror’s distance from the
original surface. This parameter is animatable.
Flip Normals—Lets you flip the surface normals.
Mirror Surface rollout (modification tim e)
Mirror Axis group
The Mirror Axis buttons control the direction in
which the or iginal sur face is mirrored.
You can’t transform the mirror surface directly
(that would simply transform the mirror surface
and its parent surface at the same time). You
transform it by t ransforming its g izmo. By using
transforms you can mirror about an arbitrary axis,
rather than using one of the Mirror Axis presets.
When you transform a mirror surface, you are
actually transforming the mirror plane, so Rotate
has the effect of rotating the plane about which
the surface is m irrored. (This is like rotating the
mirror gizmo in the Mirror modifier.)
Tip: A convenient way to guarantee that a sur face
is sy mmetrical is to create one side of the surface,
mirror that surface, and then create a blend
between the two sides.
Offset—Controls the mirror’s distance from the
original surface. This parameter is animatable.
ReplaceBaseSurface—Lets you replace the parent
surface. Click the button, then click the new
surfaceonwhichtobasethemirror.
Ex trude Sur fa ce
Select NURBS object. > Modify panel > Create Surfaces
rollout > Dependent Surfaces group box > Extrude
Select NURBS object. > Modify panel > NURBS toolbox >
Create Extrude Surface button
An extrude surface is extruded from a curve
sub-object. It is similar to a surface created with
the Extrude modifier. The advantage is that an
extrudesub-objectispartoftheNURBSmodel,so
you can use it to construct other curve and surface
sub-objects.