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156 Chapter 5: Creating Geometry
Tor us, Plane, Cone, GeoSphere, Tube, Teapot, and
Pyramid.
Extended Primitives—More complex 3D objects
such as Capsule, OilTank, Spindle, Hedra, Torus
Knot, and Prism.
Co mpound Objects—Compound objects include
Scatter, Connect, ShapeMerge, Bo oleans, Morph,
BlobMesh,Terrain,andLoft.Booleanscombine
the geometry of two objects using union,
int ersection, and difference operations. Morphs
are animated objects that change one geometric
shape into other shapes over time. ShapeMerge
lets you embed a spline shape into a geometric
mesh. Loft (page 1–352) uses shapes as cross
sect ions along a path to produce a 3D object.
Particle Systems—Animated objects that simulate
spray, snow, blizzard, and simi lar collect ions of
small objects.
Patch Gr i ds—Simple 2D surfaces ready for
modeling or repairing existing meshes.
NURB S S ur fa ces—Analytically generated sur faces
especially suited for modeling surfaces with
complicated curves.
AE C Extended—Elements useful for AEC desi gn,
including Terrain, Foliage (plants and t rees),
Railing, for creating custom railings, and Wall, for
the production of Wall objects.
Stairs—Four t ypes of stairs: Spiral, L-Type,
Straight, and U-Type.
Doors —Parametric door styles include Pivot,
BiFold, and Sliding.
Windows—Parametric window styles include
Awning,Fixed,Projected,Casement,Pivoted,and
Sliding.
Note: Default materials are automatically applied
to Foliage, as well as to the following object ty pes:
Railing, Stairs, Doors, and Windows.
Dynamics Objects—Objects designed for use in
dynamics simulations.
Shape Types
Splines—Common 2D shapes such as a Line,
Rectangle,Circle,Ellipse,Arc,Donut,NGon,and
Star. Text shapes support Tr ueTy pe fonts. Sect ion
creates a spline from the cross-section of an object.
Helix is a 3D shape.
NUR B S Curves —A Point Curve and CV Curve
provide the starting points for complex surfaces.
See Introduction to NURBS Modeling (page
1–1078).
Ex tended Splines—More complex 2D shapes
including Walled Rectangle, Channel Spline,
AngleSpline,TeeSpline,andWideFlangeSpline.
Extended splines can be use d in architectural and
similar applications.
Var ying the Parameters
Unlike physical building blocks, with fixed shape
and size, you can change the parameters of objects
and shapes to dramatically alter topolog y. Here are
some examples of changes you can make:
• Turnaconeintoafour-sidedpyramidby
reducing the number of sides and turning the
Smooth option off.
• Slice any circular object as if it were a pie.
• Animate almost al l creation parameters, and
interactively change their settings during
animation playback.
• Render splines directly at any assigned width.
• Break, detach, and divide wall segments.
• Change the number of risers without affecting
the overall rise of the st a irs.
Collapsing Primitives to B ase Geometry
You can collapse a building-block object to one
of a variety of base geometric types once you no