2004

308 | Chapter 16 Draw Geometric Objects
Create 3D Solids
A solid object represents the entire volume of an object. Solids are the most
informationally complete and least ambiguous of the 3D modeling types.
Complex solid shapes are also easier to construct and edit than wireframes
and meshes.
You create solids from one of the basic solid shapes of box, cone, cylinder,
sphere, torus, and wedge or by extruding a 2D object along a path or
revolving a 2D object about an axis.
Once you have created a solid in this manner, you can create more complex
shapes by combining solids. You can join solids, subtract solids from each
other, or find the common volume (overlapping portion) of solids. For more
information, see “Create a Composite Solid” on page 312.
Solids can be further modified by filleting, chamfering, or changing the color
of their edges. Faces on solids are easily manipulated because they don’t
require you to draw any new geometry or perform Boolean operations on the
solid. AutoCAD also provides commands for slicing a solid into two pieces or
obtaining the 2D cross section of a solid (see “Modify 3D Solids” on page
429).
Like meshes, solids are displayed as wireframes until you hide, shade, or
render them. Additionally, you can analyze solids for their mass properties
(volume, moments of inertia, center of gravity, and so on). You can export
data about a solid object to applications such as NC (numerical control)
milling or FEM (finite element method) analysis. By exploding a solid, you
can break it down to mesh and wireframe objects.
The
ISOLINES system variable controls the number of tessellation lines used
to visualize curved portions of the wireframe. The
FACETRES system variable
adjusts the smoothness of shaded and hidden-line objects.
Create a Solid Box
You can use
BOX to create a solid box. The base of the box is always parallel
to the XY plane of the current UCS.
1
3
2