Graphics Programs Reference
In-Depth Information
2.
Click the blue Jordan Court FGCL profile to display its grips. Click
the upright triangular grip located in the circle marked A1, and drag
it to the center of the circle marked A2, as shown in Figure 7.3.
◀
This is an example of
moving the PVI grip,
which changes the
slope of both tangents,
maintains the length
of the curve, and keeps
the curve tangent at
both ends.
This type of grip moves
the PVI along the slope
of one of the tangents.
FiGuRE 7.3
Moving a PVI grip
3.
At the circle marked B1, click the triangle grip on the right and drag
it to the center of the circle marked B2, as shown in Figure 7.4.
◀
This grip moves a
tangent while keeping
its slope constant. The
result is that the PVIs
at either end of the
tangent are raised or
lowered, and the curve
geometry associated
with them must update.
FiGuRE 7.4
Moving a tangent slope grip
4.
Click the square grip at the center of circle C1, and move it to the
center of circle C2, as shown in Figure 7.5.
◀
For vertical curves, the
curve length refers to
the horizontal distance
from the beginning of
the curve to the end.
5.
Click the circular grip located at the center of circle D1, and move it
to the center of circle D2, as shown in Figure 7.6.
This is an example of moving the pass-through grip, forcing the curve
to pass through a given point while adjusting the length of the curve.
6.
Click the circular grip at the center of circle E1, and move it to the
center of circle E2, as shown in Figure 7.7.
This is an example of moving the endpoint grip of the curve, which
also moves the start point to adjust the length of the curve.
◀
