9

Extrude Surface 1189
Surface extruded from a cu rve
Procedure
To create a n ex tr ude su r f a ce:
1.
In a NURBS object that contains at least
one c urve, turn on Extrude.
2. Move the cursor over the curve to extrude, and
drag to se t the ini
tial amount.
By default, the sur
face extr udes along the
NURBS mo del’s local Z axis. A gizmo (yellow
by default) indicates the direction of extrusion.
Transfor m in g the
extrude surface’s gizmo
changes the direction of the extrude, lett ing you
extrude a long an axis that isn’t aligned with a
local coordina
te axis.
The Flip Normal
scontrolletsyouflipthe
surface normals at creation time. (After
creation, you can flip normals using controls on
the Surface Co
mmon rollout.)
3. Adjust the ext
rusion parameters.
Inter face
While an extrude sub-object is selected, a rollout
w ith the extrusion parameters is displayed at the
bottom of the
Modify panel.
Extrude Sur face rollout (creation time)
Amount—Thedistancethesurfaceisextruded
from the parent curve in current 3ds Max units.
This parameter is animatable.
Direction group
X, Y a nd Z—Choose the axis of extrusion.
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.
This control is disabled if the curve is not a closed
curve.
Thestartpointisdisplayedasabluecircle.
Flip Normals—Lets you flip the surface normals
at creation time. (After creation, you can flip
normals using controls in the Surface Common
rollout.)
Cap—When on, two surfaces are generated to close
theendsoftheextrusion.Whiletheyarepresent,
the c ap surfaces are maintained so they match the
dimensions of the extrude surface. The parent
curvemustbeaclosedcurve.
The Cap check box appears only on the creation
rollout. If you want to remove the caps later, simply
select them as sur face sub-objects and delete them.
Think of extrude capping as a workflow shortcut