8

152 Chapter 5: Creating Geometry
NURB S Cur ves—
A Point Curve and CV Curve
provide the starting points for complex surfaces.
See
Introduction to NURBS Modeling (page
1–1079)
.
Extended S plines—More complex 2D shapes
including Walled Rectangle, Channel Spline,
Angle Spline, Tee Spline, and Wide Flange Spline.
Extended spline s can be used in architectural an d
similar applic ations.
Varying the Parameters
Unlike physical building blocks, with fixed shape
and s ize, you can change the parameters of objects
and shapes to dramatically a lter topology. Here are
some examples of changes you can make:
• Turnaconeintoafour-sidedpyramidby
reducing the number of s ides and tur ning the
Smooth option off.
• Slice any circular object as if it were a pie.
• Animate almost all creation parameters, and
interactively change their settings during
animation playback.
• Render splines directly at any assigned width.
• Break, detach, and divide wal l segments.
• Change the number of risers without affecting
theoverallriseofthestairs.
Colla psing Pr imitives to B ase Geometr y
You can collapse a building-block object to one
of a variety of base geometric types once you no
longer need access to its creation parameters. For
example, you can convert any standard primitive
to an
editable mesh (page 1–984) , editable poly
(page 1–1012)
, editable patch (page 1–950) ,or
NURBS (page 1–1093) object, and you can conv ert
asplineshapetoaneditablemesh,
editable spline
(page 1–284)
,orNURBSobject.Theeasiestway
to collapse an object is to select it, right-click it,
and choose a "Convert to" option from the quad
menu > Transform quadrant. This lets you use
explicit editing methods with the object, such as
transforming vertices. You can also use the Modify
panel to collapse a primitive.
Ma pping Coordina tes
MostGeometryobjectshaveanoptionfor
generating mapping coordinates. Objects need
these mapping coordinates if you plan to apply
amappedmaterialtothem. Mappedmaterials
include a wide range of rendered effects, from
2D bitmaps to reflections and refractions. See
Mapping Coordinates (p age 2–1249) and Using
Maps to Enhance a Material (page 2–1247)
.If
mapping coordinates have a lready b een applied to
an object, the check b ox for this feature is turned
on.
Cre ating an O b ject
With some variations, the steps show n in the
following images apply to creating any type of
object on the Create panel. F or specific examples,
see the Procedures sect ion in any object’s topic.
1. Diameter defined
2. Height defined