Chapter 1 Introduction to Three-Dimensional Modeling
15
Copyright Goodheart-Willcox Co., Inc.
3D Construction Techniques 3D Construction Techniques
Before constructing a 3D model, you should determine the purpose of your
design. What will the model be used for—manufacturing, analysis, or presentation?
This helps you determine which tools you should use to construct and display the
model. Three-dimensional objects can be drawn as solids, meshes, or surfaces and
displayed in wireframe, hidden-line removed, and shaded views.
A wireframe object, or model, is an object constructed of lines in 3D space.
Wireframe models are hard to visualize because it is diffi cult to determine the angle
of view and the nature of the surfaces represented by the lines. The
HIDE
command
has no effect on a true wireframe model because there is nothing to hide. All lines are
always visible because there are no surfaces or faces between the lines. True wireframe
models have very limited applications.
Surface modeling represents solid objects by creating a skin in the shape of the
object. However, there is nothing inside of the object. Think of a surface model as a
balloon fi lled with air. A surface model looks more like the real object than a wire-
frame and can be used for rendering. Surface models are often constructed for applica-
tions such as civil engineering terrain modeling, automobile body design, sheet metal
design and fabrication, and animation. Surface modeling techniques are discussed in
Chapter 10.
Rendered
image
Renderings
completed in
this drawing
session
Figure 1-17.
The rendered model is displayed in the
Render
window.
Figure 1-16.
Rendering produces
the most realistic
display of a scene.