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1190 Chapter 9: Surface Modeling
rather than a property (or parameter) of extr ude
surfaces.
To f l ip t h e nor m a l o f a n e x t r u de c ap, s elec t it a s a
Surface sub-object and use the Flip Normals toggle
on the Surface Common rollout.
Extrude Surface rollout (modification time)
Amount—The distance the surface is extruded
fromtheparentcurveincurrent3dsMaxunits.
Direction group
X, Y a nd Z— Cho ose the axis of ext rusion.
Default=Z.
Start Point—Adjusts the position of the curve’s
start point. This can help eliminate unwanted
tw ists or "buckles" in the surface.
Thiscontrolisdisabledifthecurveisnotaclosed
cur ve.
Thestartpointisdisplayedasabluecircle.
Replace Base Curve—Lets you replace the parent
curve. Click the button, then click the new curve
on which to base the extruded surface.
Lathe Sur face
Select NURBS object. > Modify panel > Create Surfaces
rollout>DependentSurfacesgroupbox>Lathe
Select NURBS object. > Modify panel > NURBS toolbox >
Create Lathe Surface button
A lathe surface is generated from a cur ve
sub-object. It is similar to a surface created with
the Lathe modifier. The advantage is that a lathe
sub-object is part of the NURB S model, so you
can use it to construct other curve and surface
sub-objects.
Surface created by lathing a curve
Procedure
To create a lat he surf ace:
1.
In a NURBS object that contains at least
one curve, turn on Lathe.
2. Click the curve to lathe.
The lathe surface rotates about the NURBS
model’s local Y axis. The initial lathe amount
is 360 degrees. A gizmo (yellow by default)
indicates the axis of the lathe. Transforming the
lathe surface’s gizmo changes the shape of the
lathe,andletsyoulathearoundanaxisthatisn’t
aligned with a local coordinate axis.