Graphics Programs Reference
In-Depth Information
Figure 17.34
Extrusion constrained to the reference line
Althoughreferencelinesworkwellforthistypeofconstraintandparametric
behavior, they can cause undesired results when the angle of solid geometry
is supposed to change while the geometry remains in a fixed location. The
solid geometry shown in
Figure 17.35
is a sweep with a rectangular profile.
The path of the sweep is an arc that is locked to the reference line and to the
reference plane. As the Angle parameter is modified, the length of the sweep
increases. A Radius parameter has also been applied for the sweep path.
Figure 17.35
Sweep constrained to the reference line
This type ofparametric relationship will behave as expected—up toa certain
point. Flexing the family reveals that, at larger angles, the geometry may
not stay associated to the reference line, which could cause an incorrect
representation of the solid, as shown in
Figure 17.36
. Notice that the solid
