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1216 Chapter 9: Sur face Modeling
Multicur ve Tr immed S ur face
SelectNURBSobject.>Modifypanel>CreateSurfaces
rollout > Dependent Surfaces group box > Multi-Trim
Select NU RB S object. > Modify panel > NURBS toolbox >
Create a Multicurve Trimmed S urface bu tto n
Creating a multicurve trimmed sur face
A multicurve trimmed surface is an existing
surface trimmed by multiple curves that form a
loop.
When you create a multicur ve trimmed surface,
you create only
one trimmed hole. If you want
to create multiple holes, first create holes in the
surface using other techniques, and as the final
step create the multicur ve t rim.
You can’t trim across the edge between two
surfaces, or across a "seam" w here a surface
touches itself, as at the back of a spherical surface
created by converting a Sphere pr imitive.
Procedure
To create a multicurve trim:
1.
Create a loop out of multiple curve sub-objects.
2. AttheCurveCVorPointsub-objectlevel,use
Fuse to connect the ends of the curves.
The curv es must form a single closed loop, or
completely traverse the surface.
3. Project the curves onto the surface by creating
a normal or vector projected curve for each
curve in the loop.
Tip: YoucanalsouseCVorpointcurveon
surfaceforthesecurves.
4. Turn on Multicurve Trimmed Surface
in the toolbox or Multi-Trim on the Create
Surfaces rollout.
5. Click the surface to trim, then click each of the
curves in the loop. Right-click to e nd creation.
TheTrimlistshowsthenamesofthecurves
you select. Flip Trim inverts the direction of
trimming. Flip Normals lets you flip the surface
normals at creation time. (After you have
created the sur face, you c an flip norma ls u sing
controls on the Surface Common rollout.)
Interf ace
While a multicurve trimmed sub-object is selected,
arolloutwiththemulticurvetrimparameters
appears. This rollout appears only when
one
multicur ve trimmed sub-object is selected. It
isn’tpossibletoeditmorethanonemulticurve
trimmedobjectatatime,sounlikesomeother
NURBS sub-objects, the rollout doesn’t appear
when multiple multicurve trimmed sub-objects
are selected.
Tip: When you edit a multicurve trimmed
sub-object, close the Surface Common rollout
to see the Multicurve Trim Surface rollout more
easily.