174 Exploring Drafting
Figure 7-20 A solid model represents the entire mass of an object and the material
used in its construction. (Designed with Solid Edge from Siemens PLM Software)
are used in mechanical drafting applications
because they can be analyzed for properties
such as mass and volume.
Models created in surface modeling are g
similar to solid models, but the objects are
not defined as solid. Surface models have an
outer “skin” to represent exterior surfaces.
See Figure 7-21. While a surface model is not
considered as realistic as a solid model, the
quality of the representation is very similar.
Therefore, surface models are primarily used
for presentation purposes.
Parametric modeling is an advanced g
form of modeling that allows feature dimen-
sions, or parameters, to be modifi during fied
the construction of a model. In this type of
Figure 7-21 A surface model is a representation of
the outer “skin” of the various surfaces simulating the
object. (Discreet, a division of Autodesk)