8
602 Chapter 8: Modifiers
• A MultiSegment in the attempted seam contains
segments that are not contiguous and that are
not linked by any seam.
Cross S ecti on M odif i er
Select a spline object w ith spline cross sec tions. > M odify
panel > Modifier List > CrossSection
Make a selection. > Mo difiers menu > Patch/Spline
Editing > CrossSection
The CrossSection modifier creates a "skin" across
multiple splines. It works by connecting the
vertices of 3D splines to form a skin. The resulting
object is another spline object that can be used
w ith the
Surface modifier (page 1–833)
to create
a patch surface. These two modifiers, when used
together, are sometimes referred to collectively as
“Surface Tools.”
CrossSection uses splines to create a model of a boat.
CrossSectioncanbuildaskinacross
various-shaped splines with different ver tex counts
and open/closed status. The more different the
splines in vertex count and complexity, the more
likelytheskinwillhavediscontinuity.
Note: Similar functionality is provided by the
Editable Spline object (page 1–284)
.Atthe
Editable Spline > Segment and Spline sub-object
levels, you can creat e a spline cage using Connect
CopyandCrossSection. Usingthismethod,
you need to region-select the created vertices to
transform t hem. A lso, this method lets you define
the ordering of the spline more easily than does
the CrossSection modifier.
Procedures
Ex ample: To ex plor e t he CrossS ection modi fi er:
1.
OntheCreatepanel,clickShapes,
then click Circle.
2. Drag in the Top viewport to create a circle about
100 units in radius.
3. On the Modify panel, choose Edit Spline
from the Modifier List.
4. In the modifier stack display, turn on Spline
sub-object, then selec t the circle.
5. In the Front viewport, SHIFT+Move the spline
up to copy it.
6. SHIFT+Movethecopyuptocreateathird
circle.
Note: The order that you attach or clone splines
is importa nt: this is the order that CrossSe ction
uses to create the skin.
7. On the Modif y panel, choose
CrossSection from the Modifier List.
CrossSection joins the vertices of the three
circles. A basic spline cylinder is displayed.