Chapter 7: Selecting Features
the middle, a loft is a better choice because it enables you to explicitly define the cross-section at
any point. However, if the outline is more important than the cross-section, you should choose a
sweep. In addition, if the path between ends is important, choose a sweep.Both types of features are extremely powerful, but the sweep has a tendency to be fussier about
details, setup, and rules, while the loft can be surprisingly flexible. I am not trying to dissuade you
from using sweeps, because they are useful in many situations. However, in my own personal
modeling, I probably use about ten lofts for every sweep. For example, while you would use a loft
or combination of loft features to create the outer faces of a complex laundry detergent bottle, you
would use the sweep to create a raised border around the label area or the cap thread.A good example of the interpolated nature of a loft is to put a circle on one plane and a rectangle
on an offset plane and then loft them together. This arrangement is shown in Figure 7.8. The tran-
sition between shapes is the defining characteristic of a loft, and is the reason for choosing a loft
instead of another feature type. Lofts can create both Boss features and Cut features.FIGURE 7.8A simple loft
Both shapes are two-profile lofts. The two-profile loft with default end conditions always creates a
straight transition, which is shown in the image to the left. A two-point spline with no end tan-
gency creates a straight line in exactly the same way. By applying end conditions to either or both
of the loft profiles, the loft’s shape is made more interesting, as seen in the image to the right in
Figure 7.8. Again, the same thing happens when applying end tangency conditions to a two-point
spline: it goes from being a straight line to being more curvaceous, with continuously variable cur-
vature. The Loft PropertyManager interface is shown in Figure 7.9.