Graphics Programs Reference
In-Depth Information
Chapter 22
Editing and Visualizing 3D Solids
In the previous 3D chapters, you spent some time becoming familiar with the AutoCAD 3D
modeling features. In this chapter, you'll focus on 3D solids and how they're created and edited.
You'll also learn how you can use some special visualization tools to show your 3D solid in a
variety of ways.
You'll create a fictitious mechanical part to explore some of the ways you can shape 3D sol-
ids. This will also give you a chance to see how you can turn your 3D model into a standard 2D
mechanical drawing. In addition, you'll learn about the 3D solid editing tools that are available
through the Tool Sets palette and the menu bar.
In this chapter, you'll learn to do the following:
Understand solid modeling
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Create solid forms
Create complex solids
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Edit solids
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Streamline the 2D drawing process
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Visualize solids
Understanding Solid Modeling
Solid modeling is a way of defining 3D objects as solid forms. When you create a 3D model by
using solid modeling, you start with the basic forms of your model—cubes, cones, and cylin-
ders, for example. These basic solids are called
primitives.
Then, using more of these primitives,
you begin to add to or subtract from your basic forms.
For example, to create a model of a tube, you first create two solid cylinders, one smaller in
diameter than the other. You then align the two cylinders so that they're concentric and tell
AutoCAD to subtract the smaller cylinder from the larger one. The larger of the two cylinders
becomes a tube whose inside diameter is that of the smaller cylinder, as shown in Figure 22.1.
Several primitives are available for modeling solids in AutoCAD (Figure 22.2).
You can join these shapes—polysolid, box, wedge, cone, sphere, cylinder, pyramid, and donut
(or
torus
)—in one of four ways to produce secondary shapes. The first three, demonstrated in
Figure 22.3 using a cube and a cylinder as examples, are called
Boolean operations.
(The name
comes from the nineteenth-century mathematician George Boole.)
