2012

TIP Not visible in the illustration is a blue axis arrow grip that points toward you.
This axis is visible in other views such as a 3D isometric view, and can be used to
modify the shape of a spline in 3D.
Click the downward-pointing triangular grip to switch to the Move Tangent
Direction option as illustrated below. Even though the axes of the gizmo
change their location, the base point remains the same. With this option,
moving the square grip changes the slope of the tangent at the base point.
The tangent arrow grip changes the magnitude of the tangent at the base
point, creating either a sharper or a flatter curvature at the base point. In the
illustration, the magnitude of the tangent is being increased.
Edit Splines with a Palette
The Properties palette provides access to several spline parameters and options,
including the degree of the spline, the weight for each control point, the knot
parameterization method used in conjunction with fit points, and whether the
spline is closed. For more information, see
Draw Splines on page 723.
Trim, Extend, and Fillet Splines
Trimming a spline shortens it without changing the shape of the portion that
remains. Extending a spline lengthens it by adding a linear portion that is
tangent to the end of the spline (C1 continuity). If the shape of the spline is
later changed, the tangency of the linear portion is not maintained.
Trimming a spline shortens it without changing the shape of the portion that
remains.
Filleting a spline creates an arc that is tangent to the spline and the other
selected object. The spline might be extended with a linear portion to complete
the fillet operation.
856 | Chapter 19 Select and Modify Objects