Graphics Programs Reference
In-Depth Information
FIGURE 20.58
The 3D solid
representing
the excavation
FIGURE 20.59
The Command
Line palette
expanded to show
the mass and vol-
ume information
from the Massprop
command
Understanding the Loft Command
As you've seen from the exercises in this chapter, the Loft command lets you create just about
any shape you can imagine, from a simple sling to the complex curves of a contour map. If your
loft cross sections are a set of closed objects like circles or closed polygons, the resulting object
is a 3D solid instead of a surface when the Mode option is set to solid. Setting Mode to Surface
causes the Loft command to create a surface instead of a 3D solid when lofting closed objects.
The order in which you select the cross sections is important because Loft will follow your
selection order to create the surface or solid. For example, Figure 20.60 shows a series of circles
used for a lofted solid. The circles are identical in size and placement, but the order of selection
is different. The solid on the left was created by selecting the circles in consecutive order from
bottom to top, creating an hourglass shape. The solid on the right was created by selecting the
two larger circles fi rst from bottom to top; the smaller, intermediate circle was selected last. This
selection order created a hollowed-out shape with sides that are more vertical.
